diff options
Diffstat (limited to 'net/packet/af_packet.c')
| -rw-r--r-- | net/packet/af_packet.c | 4791 |
1 files changed, 4791 insertions, 0 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c new file mode 100644 index 0000000000..7adf48549a --- /dev/null +++ b/net/packet/af_packet.c @@ -0,0 +1,4791 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * PACKET - implements raw packet sockets. + * + * Authors: Ross Biro + * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> + * Alan Cox, <gw4pts@gw4pts.ampr.org> + * + * Fixes: + * Alan Cox : verify_area() now used correctly + * Alan Cox : new skbuff lists, look ma no backlogs! + * Alan Cox : tidied skbuff lists. + * Alan Cox : Now uses generic datagram routines I + * added. Also fixed the peek/read crash + * from all old Linux datagram code. + * Alan Cox : Uses the improved datagram code. + * Alan Cox : Added NULL's for socket options. + * Alan Cox : Re-commented the code. + * Alan Cox : Use new kernel side addressing + * Rob Janssen : Correct MTU usage. + * Dave Platt : Counter leaks caused by incorrect + * interrupt locking and some slightly + * dubious gcc output. Can you read + * compiler: it said _VOLATILE_ + * Richard Kooijman : Timestamp fixes. + * Alan Cox : New buffers. Use sk->mac.raw. + * Alan Cox : sendmsg/recvmsg support. + * Alan Cox : Protocol setting support + * Alexey Kuznetsov : Untied from IPv4 stack. + * Cyrus Durgin : Fixed kerneld for kmod. + * Michal Ostrowski : Module initialization cleanup. + * Ulises Alonso : Frame number limit removal and + * packet_set_ring memory leak. + * Eric Biederman : Allow for > 8 byte hardware addresses. + * The convention is that longer addresses + * will simply extend the hardware address + * byte arrays at the end of sockaddr_ll + * and packet_mreq. + * Johann Baudy : Added TX RING. + * Chetan Loke : Implemented TPACKET_V3 block abstraction + * layer. + * Copyright (C) 2011, <lokec@ccs.neu.edu> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/ethtool.h> +#include <linux/filter.h> +#include <linux/types.h> +#include <linux/mm.h> +#include <linux/capability.h> +#include <linux/fcntl.h> +#include <linux/socket.h> +#include <linux/in.h> +#include <linux/inet.h> +#include <linux/netdevice.h> +#include <linux/if_packet.h> +#include <linux/wireless.h> +#include <linux/kernel.h> +#include <linux/kmod.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <net/net_namespace.h> +#include <net/ip.h> +#include <net/protocol.h> +#include <linux/skbuff.h> +#include <net/sock.h> +#include <linux/errno.h> +#include <linux/timer.h> +#include <linux/uaccess.h> +#include <asm/ioctls.h> +#include <asm/page.h> +#include <asm/cacheflush.h> +#include <asm/io.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/poll.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/mutex.h> +#include <linux/if_vlan.h> +#include <linux/virtio_net.h> +#include <linux/errqueue.h> +#include <linux/net_tstamp.h> +#include <linux/percpu.h> +#ifdef CONFIG_INET +#include <net/inet_common.h> +#endif +#include <linux/bpf.h> +#include <net/compat.h> +#include <linux/netfilter_netdev.h> + +#include "internal.h" + +/* + Assumptions: + - If the device has no dev->header_ops->create, there is no LL header + visible above the device. In this case, its hard_header_len should be 0. + The device may prepend its own header internally. In this case, its + needed_headroom should be set to the space needed for it to add its + internal header. + For example, a WiFi driver pretending to be an Ethernet driver should + set its hard_header_len to be the Ethernet header length, and set its + needed_headroom to be (the real WiFi header length - the fake Ethernet + header length). + - packet socket receives packets with pulled ll header, + so that SOCK_RAW should push it back. + +On receive: +----------- + +Incoming, dev_has_header(dev) == true + mac_header -> ll header + data -> data + +Outgoing, dev_has_header(dev) == true + mac_header -> ll header + data -> ll header + +Incoming, dev_has_header(dev) == false + mac_header -> data + However drivers often make it point to the ll header. + This is incorrect because the ll header should be invisible to us. + data -> data + +Outgoing, dev_has_header(dev) == false + mac_header -> data. ll header is invisible to us. + data -> data + +Resume + If dev_has_header(dev) == false we are unable to restore the ll header, + because it is invisible to us. + + +On transmit: +------------ + +dev_has_header(dev) == true + mac_header -> ll header + data -> ll header + +dev_has_header(dev) == false (ll header is invisible to us) + mac_header -> data + data -> data + + We should set network_header on output to the correct position, + packet classifier depends on it. + */ + +/* Private packet socket structures. */ + +/* identical to struct packet_mreq except it has + * a longer address field. + */ +struct packet_mreq_max { + int mr_ifindex; + unsigned short mr_type; + unsigned short mr_alen; + unsigned char mr_address[MAX_ADDR_LEN]; +}; + +union tpacket_uhdr { + struct tpacket_hdr *h1; + struct tpacket2_hdr *h2; + struct tpacket3_hdr *h3; + void *raw; +}; + +static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, + int closing, int tx_ring); + +#define V3_ALIGNMENT (8) + +#define BLK_HDR_LEN (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT)) + +#define BLK_PLUS_PRIV(sz_of_priv) \ + (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT)) + +#define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status) +#define BLOCK_NUM_PKTS(x) ((x)->hdr.bh1.num_pkts) +#define BLOCK_O2FP(x) ((x)->hdr.bh1.offset_to_first_pkt) +#define BLOCK_LEN(x) ((x)->hdr.bh1.blk_len) +#define BLOCK_SNUM(x) ((x)->hdr.bh1.seq_num) +#define BLOCK_O2PRIV(x) ((x)->offset_to_priv) + +struct packet_sock; +static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pt, struct net_device *orig_dev); + +static void *packet_previous_frame(struct packet_sock *po, + struct packet_ring_buffer *rb, + int status); +static void packet_increment_head(struct packet_ring_buffer *buff); +static int prb_curr_blk_in_use(struct tpacket_block_desc *); +static void *prb_dispatch_next_block(struct tpacket_kbdq_core *, + struct packet_sock *); +static void prb_retire_current_block(struct tpacket_kbdq_core *, + struct packet_sock *, unsigned int status); +static int prb_queue_frozen(struct tpacket_kbdq_core *); +static void prb_open_block(struct tpacket_kbdq_core *, + struct tpacket_block_desc *); +static void prb_retire_rx_blk_timer_expired(struct timer_list *); +static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *); +static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *); +static void prb_clear_rxhash(struct tpacket_kbdq_core *, + struct tpacket3_hdr *); +static void prb_fill_vlan_info(struct tpacket_kbdq_core *, + struct tpacket3_hdr *); +static void packet_flush_mclist(struct sock *sk); +static u16 packet_pick_tx_queue(struct sk_buff *skb); + +struct packet_skb_cb { + union { + struct sockaddr_pkt pkt; + union { + /* Trick: alias skb original length with + * ll.sll_family and ll.protocol in order + * to save room. + */ + unsigned int origlen; + struct sockaddr_ll ll; + }; + } sa; +}; + +#define vio_le() virtio_legacy_is_little_endian() + +#define PACKET_SKB_CB(__skb) ((struct packet_skb_cb *)((__skb)->cb)) + +#define GET_PBDQC_FROM_RB(x) ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc)) +#define GET_PBLOCK_DESC(x, bid) \ + ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer)) +#define GET_CURR_PBLOCK_DESC_FROM_CORE(x) \ + ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer)) +#define GET_NEXT_PRB_BLK_NUM(x) \ + (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \ + ((x)->kactive_blk_num+1) : 0) + +static void __fanout_unlink(struct sock *sk, struct packet_sock *po); +static void __fanout_link(struct sock *sk, struct packet_sock *po); + +#ifdef CONFIG_NETFILTER_EGRESS +static noinline struct sk_buff *nf_hook_direct_egress(struct sk_buff *skb) +{ + struct sk_buff *next, *head = NULL, *tail; + int rc; + + rcu_read_lock(); + for (; skb != NULL; skb = next) { + next = skb->next; + skb_mark_not_on_list(skb); + + if (!nf_hook_egress(skb, &rc, skb->dev)) + continue; + + if (!head) + head = skb; + else + tail->next = skb; + + tail = skb; + } + rcu_read_unlock(); + + return head; +} +#endif + +static int packet_xmit(const struct packet_sock *po, struct sk_buff *skb) +{ + if (!packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS)) + return dev_queue_xmit(skb); + +#ifdef CONFIG_NETFILTER_EGRESS + if (nf_hook_egress_active()) { + skb = nf_hook_direct_egress(skb); + if (!skb) + return NET_XMIT_DROP; + } +#endif + return dev_direct_xmit(skb, packet_pick_tx_queue(skb)); +} + +static struct net_device *packet_cached_dev_get(struct packet_sock *po) +{ + struct net_device *dev; + + rcu_read_lock(); + dev = rcu_dereference(po->cached_dev); + dev_hold(dev); + rcu_read_unlock(); + + return dev; +} + +static void packet_cached_dev_assign(struct packet_sock *po, + struct net_device *dev) +{ + rcu_assign_pointer(po->cached_dev, dev); +} + +static void packet_cached_dev_reset(struct packet_sock *po) +{ + RCU_INIT_POINTER(po->cached_dev, NULL); +} + +static u16 packet_pick_tx_queue(struct sk_buff *skb) +{ + struct net_device *dev = skb->dev; + const struct net_device_ops *ops = dev->netdev_ops; + int cpu = raw_smp_processor_id(); + u16 queue_index; + +#ifdef CONFIG_XPS + skb->sender_cpu = cpu + 1; +#endif + skb_record_rx_queue(skb, cpu % dev->real_num_tx_queues); + if (ops->ndo_select_queue) { + queue_index = ops->ndo_select_queue(dev, skb, NULL); + queue_index = netdev_cap_txqueue(dev, queue_index); + } else { + queue_index = netdev_pick_tx(dev, skb, NULL); + } + + return queue_index; +} + +/* __register_prot_hook must be invoked through register_prot_hook + * or from a context in which asynchronous accesses to the packet + * socket is not possible (packet_create()). + */ +static void __register_prot_hook(struct sock *sk) +{ + struct packet_sock *po = pkt_sk(sk); + + if (!packet_sock_flag(po, PACKET_SOCK_RUNNING)) { + if (po->fanout) + __fanout_link(sk, po); + else + dev_add_pack(&po->prot_hook); + + sock_hold(sk); + packet_sock_flag_set(po, PACKET_SOCK_RUNNING, 1); + } +} + +static void register_prot_hook(struct sock *sk) +{ + lockdep_assert_held_once(&pkt_sk(sk)->bind_lock); + __register_prot_hook(sk); +} + +/* If the sync parameter is true, we will temporarily drop + * the po->bind_lock and do a synchronize_net to make sure no + * asynchronous packet processing paths still refer to the elements + * of po->prot_hook. If the sync parameter is false, it is the + * callers responsibility to take care of this. + */ +static void __unregister_prot_hook(struct sock *sk, bool sync) +{ + struct packet_sock *po = pkt_sk(sk); + + lockdep_assert_held_once(&po->bind_lock); + + packet_sock_flag_set(po, PACKET_SOCK_RUNNING, 0); + + if (po->fanout) + __fanout_unlink(sk, po); + else + __dev_remove_pack(&po->prot_hook); + + __sock_put(sk); + + if (sync) { + spin_unlock(&po->bind_lock); + synchronize_net(); + spin_lock(&po->bind_lock); + } +} + +static void unregister_prot_hook(struct sock *sk, bool sync) +{ + struct packet_sock *po = pkt_sk(sk); + + if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) + __unregister_prot_hook(sk, sync); +} + +static inline struct page * __pure pgv_to_page(void *addr) +{ + if (is_vmalloc_addr(addr)) + return vmalloc_to_page(addr); + return virt_to_page(addr); +} + +static void __packet_set_status(struct packet_sock *po, void *frame, int status) +{ + union tpacket_uhdr h; + + /* WRITE_ONCE() are paired with READ_ONCE() in __packet_get_status */ + + h.raw = frame; + switch (po->tp_version) { + case TPACKET_V1: + WRITE_ONCE(h.h1->tp_status, status); + flush_dcache_page(pgv_to_page(&h.h1->tp_status)); + break; + case TPACKET_V2: + WRITE_ONCE(h.h2->tp_status, status); + flush_dcache_page(pgv_to_page(&h.h2->tp_status)); + break; + case TPACKET_V3: + WRITE_ONCE(h.h3->tp_status, status); + flush_dcache_page(pgv_to_page(&h.h3->tp_status)); + break; + default: + WARN(1, "TPACKET version not supported.\n"); + BUG(); + } + + smp_wmb(); +} + +static int __packet_get_status(const struct packet_sock *po, void *frame) +{ + union tpacket_uhdr h; + + smp_rmb(); + + /* READ_ONCE() are paired with WRITE_ONCE() in __packet_set_status */ + + h.raw = frame; + switch (po->tp_version) { + case TPACKET_V1: + flush_dcache_page(pgv_to_page(&h.h1->tp_status)); + return READ_ONCE(h.h1->tp_status); + case TPACKET_V2: + flush_dcache_page(pgv_to_page(&h.h2->tp_status)); + return READ_ONCE(h.h2->tp_status); + case TPACKET_V3: + flush_dcache_page(pgv_to_page(&h.h3->tp_status)); + return READ_ONCE(h.h3->tp_status); + default: + WARN(1, "TPACKET version not supported.\n"); + BUG(); + return 0; + } +} + +static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec64 *ts, + unsigned int flags) +{ + struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); + + if (shhwtstamps && + (flags & SOF_TIMESTAMPING_RAW_HARDWARE) && + ktime_to_timespec64_cond(shhwtstamps->hwtstamp, ts)) + return TP_STATUS_TS_RAW_HARDWARE; + + if ((flags & SOF_TIMESTAMPING_SOFTWARE) && + ktime_to_timespec64_cond(skb_tstamp(skb), ts)) + return TP_STATUS_TS_SOFTWARE; + + return 0; +} + +static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame, + struct sk_buff *skb) +{ + union tpacket_uhdr h; + struct timespec64 ts; + __u32 ts_status; + + if (!(ts_status = tpacket_get_timestamp(skb, &ts, READ_ONCE(po->tp_tstamp)))) + return 0; + + h.raw = frame; + /* + * versions 1 through 3 overflow the timestamps in y2106, since they + * all store the seconds in a 32-bit unsigned integer. + * If we create a version 4, that should have a 64-bit timestamp, + * either 64-bit seconds + 32-bit nanoseconds, or just 64-bit + * nanoseconds. + */ + switch (po->tp_version) { + case TPACKET_V1: + h.h1->tp_sec = ts.tv_sec; + h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; + break; + case TPACKET_V2: + h.h2->tp_sec = ts.tv_sec; + h.h2->tp_nsec = ts.tv_nsec; + break; + case TPACKET_V3: + h.h3->tp_sec = ts.tv_sec; + h.h3->tp_nsec = ts.tv_nsec; + break; + default: + WARN(1, "TPACKET version not supported.\n"); + BUG(); + } + + /* one flush is safe, as both fields always lie on the same cacheline */ + flush_dcache_page(pgv_to_page(&h.h1->tp_sec)); + smp_wmb(); + + return ts_status; +} + +static void *packet_lookup_frame(const struct packet_sock *po, + const struct packet_ring_buffer *rb, + unsigned int position, + int status) +{ + unsigned int pg_vec_pos, frame_offset; + union tpacket_uhdr h; + + pg_vec_pos = position / rb->frames_per_block; + frame_offset = position % rb->frames_per_block; + + h.raw = rb->pg_vec[pg_vec_pos].buffer + + (frame_offset * rb->frame_size); + + if (status != __packet_get_status(po, h.raw)) + return NULL; + + return h.raw; +} + +static void *packet_current_frame(struct packet_sock *po, + struct packet_ring_buffer *rb, + int status) +{ + return packet_lookup_frame(po, rb, rb->head, status); +} + +static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc) +{ + del_timer_sync(&pkc->retire_blk_timer); +} + +static void prb_shutdown_retire_blk_timer(struct packet_sock *po, + struct sk_buff_head *rb_queue) +{ + struct tpacket_kbdq_core *pkc; + + pkc = GET_PBDQC_FROM_RB(&po->rx_ring); + + spin_lock_bh(&rb_queue->lock); + pkc->delete_blk_timer = 1; + spin_unlock_bh(&rb_queue->lock); + + prb_del_retire_blk_timer(pkc); +} + +static void prb_setup_retire_blk_timer(struct packet_sock *po) +{ + struct tpacket_kbdq_core *pkc; + + pkc = GET_PBDQC_FROM_RB(&po->rx_ring); + timer_setup(&pkc->retire_blk_timer, prb_retire_rx_blk_timer_expired, + 0); + pkc->retire_blk_timer.expires = jiffies; +} + +static int prb_calc_retire_blk_tmo(struct packet_sock *po, + int blk_size_in_bytes) +{ + struct net_device *dev; + unsigned int mbits, div; + struct ethtool_link_ksettings ecmd; + int err; + + rtnl_lock(); + dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex); + if (unlikely(!dev)) { + rtnl_unlock(); + return DEFAULT_PRB_RETIRE_TOV; + } + err = __ethtool_get_link_ksettings(dev, &ecmd); + rtnl_unlock(); + if (err) + return DEFAULT_PRB_RETIRE_TOV; + + /* If the link speed is so slow you don't really + * need to worry about perf anyways + */ + if (ecmd.base.speed < SPEED_1000 || + ecmd.base.speed == SPEED_UNKNOWN) + return DEFAULT_PRB_RETIRE_TOV; + + div = ecmd.base.speed / 1000; + mbits = (blk_size_in_bytes * 8) / (1024 * 1024); + + if (div) + mbits /= div; + + if (div) + return mbits + 1; + return mbits; +} + +static void prb_init_ft_ops(struct tpacket_kbdq_core *p1, + union tpacket_req_u *req_u) +{ + p1->feature_req_word = req_u->req3.tp_feature_req_word; +} + +static void init_prb_bdqc(struct packet_sock *po, + struct packet_ring_buffer *rb, + struct pgv *pg_vec, + union tpacket_req_u *req_u) +{ + struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb); + struct tpacket_block_desc *pbd; + + memset(p1, 0x0, sizeof(*p1)); + + p1->knxt_seq_num = 1; + p1->pkbdq = pg_vec; + pbd = (struct tpacket_block_desc *)pg_vec[0].buffer; + p1->pkblk_start = pg_vec[0].buffer; + p1->kblk_size = req_u->req3.tp_block_size; + p1->knum_blocks = req_u->req3.tp_block_nr; + p1->hdrlen = po->tp_hdrlen; + p1->version = po->tp_version; + p1->last_kactive_blk_num = 0; + po->stats.stats3.tp_freeze_q_cnt = 0; + if (req_u->req3.tp_retire_blk_tov) + p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov; + else + p1->retire_blk_tov = prb_calc_retire_blk_tmo(po, + req_u->req3.tp_block_size); + p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov); + p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv; + rwlock_init(&p1->blk_fill_in_prog_lock); + + p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv); + prb_init_ft_ops(p1, req_u); + prb_setup_retire_blk_timer(po); + prb_open_block(p1, pbd); +} + +/* Do NOT update the last_blk_num first. + * Assumes sk_buff_head lock is held. + */ +static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc) +{ + mod_timer(&pkc->retire_blk_timer, + jiffies + pkc->tov_in_jiffies); + pkc->last_kactive_blk_num = pkc->kactive_blk_num; +} + +/* + * Timer logic: + * 1) We refresh the timer only when we open a block. + * By doing this we don't waste cycles refreshing the timer + * on packet-by-packet basis. + * + * With a 1MB block-size, on a 1Gbps line, it will take + * i) ~8 ms to fill a block + ii) memcpy etc. + * In this cut we are not accounting for the memcpy time. + * + * So, if the user sets the 'tmo' to 10ms then the timer + * will never fire while the block is still getting filled + * (which is what we want). However, the user could choose + * to close a block early and that's fine. + * + * But when the timer does fire, we check whether or not to refresh it. + * Since the tmo granularity is in msecs, it is not too expensive + * to refresh the timer, lets say every '8' msecs. + * Either the user can set the 'tmo' or we can derive it based on + * a) line-speed and b) block-size. + * prb_calc_retire_blk_tmo() calculates the tmo. + * + */ +static void prb_retire_rx_blk_timer_expired(struct timer_list *t) +{ + struct packet_sock *po = + from_timer(po, t, rx_ring.prb_bdqc.retire_blk_timer); + struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring); + unsigned int frozen; + struct tpacket_block_desc *pbd; + + spin_lock(&po->sk.sk_receive_queue.lock); + + frozen = prb_queue_frozen(pkc); + pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); + + if (unlikely(pkc->delete_blk_timer)) + goto out; + + /* We only need to plug the race when the block is partially filled. + * tpacket_rcv: + * lock(); increment BLOCK_NUM_PKTS; unlock() + * copy_bits() is in progress ... + * timer fires on other cpu: + * we can't retire the current block because copy_bits + * is in progress. + * + */ + if (BLOCK_NUM_PKTS(pbd)) { + /* Waiting for skb_copy_bits to finish... */ + write_lock(&pkc->blk_fill_in_prog_lock); + write_unlock(&pkc->blk_fill_in_prog_lock); + } + + if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) { + if (!frozen) { + if (!BLOCK_NUM_PKTS(pbd)) { + /* An empty block. Just refresh the timer. */ + goto refresh_timer; + } + prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO); + if (!prb_dispatch_next_block(pkc, po)) + goto refresh_timer; + else + goto out; + } else { + /* Case 1. Queue was frozen because user-space was + * lagging behind. + */ + if (prb_curr_blk_in_use(pbd)) { + /* + * Ok, user-space is still behind. + * So just refresh the timer. + */ + goto refresh_timer; + } else { + /* Case 2. queue was frozen,user-space caught up, + * now the link went idle && the timer fired. + * We don't have a block to close.So we open this + * block and restart the timer. + * opening a block thaws the queue,restarts timer + * Thawing/timer-refresh is a side effect. + */ + prb_open_block(pkc, pbd); + goto out; + } + } + } + +refresh_timer: + _prb_refresh_rx_retire_blk_timer(pkc); + +out: + spin_unlock(&po->sk.sk_receive_queue.lock); +} + +static void prb_flush_block(struct tpacket_kbdq_core *pkc1, + struct tpacket_block_desc *pbd1, __u32 status) +{ + /* Flush everything minus the block header */ + +#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 + u8 *start, *end; + + start = (u8 *)pbd1; + + /* Skip the block header(we know header WILL fit in 4K) */ + start += PAGE_SIZE; + + end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end); + for (; start < end; start += PAGE_SIZE) + flush_dcache_page(pgv_to_page(start)); + + smp_wmb(); +#endif + + /* Now update the block status. */ + + BLOCK_STATUS(pbd1) = status; + + /* Flush the block header */ + +#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 + start = (u8 *)pbd1; + flush_dcache_page(pgv_to_page(start)); + + smp_wmb(); +#endif +} + +/* + * Side effect: + * + * 1) flush the block + * 2) Increment active_blk_num + * + * Note:We DONT refresh the timer on purpose. + * Because almost always the next block will be opened. + */ +static void prb_close_block(struct tpacket_kbdq_core *pkc1, + struct tpacket_block_desc *pbd1, + struct packet_sock *po, unsigned int stat) +{ + __u32 status = TP_STATUS_USER | stat; + + struct tpacket3_hdr *last_pkt; + struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; + struct sock *sk = &po->sk; + + if (atomic_read(&po->tp_drops)) + status |= TP_STATUS_LOSING; + + last_pkt = (struct tpacket3_hdr *)pkc1->prev; + last_pkt->tp_next_offset = 0; + + /* Get the ts of the last pkt */ + if (BLOCK_NUM_PKTS(pbd1)) { + h1->ts_last_pkt.ts_sec = last_pkt->tp_sec; + h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec; + } else { + /* Ok, we tmo'd - so get the current time. + * + * It shouldn't really happen as we don't close empty + * blocks. See prb_retire_rx_blk_timer_expired(). + */ + struct timespec64 ts; + ktime_get_real_ts64(&ts); + h1->ts_last_pkt.ts_sec = ts.tv_sec; + h1->ts_last_pkt.ts_nsec = ts.tv_nsec; + } + + smp_wmb(); + + /* Flush the block */ + prb_flush_block(pkc1, pbd1, status); + + sk->sk_data_ready(sk); + + pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1); +} + +static void prb_thaw_queue(struct tpacket_kbdq_core *pkc) +{ + pkc->reset_pending_on_curr_blk = 0; +} + +/* + * Side effect of opening a block: + * + * 1) prb_queue is thawed. + * 2) retire_blk_timer is refreshed. + * + */ +static void prb_open_block(struct tpacket_kbdq_core *pkc1, + struct tpacket_block_desc *pbd1) +{ + struct timespec64 ts; + struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1; + + smp_rmb(); + + /* We could have just memset this but we will lose the + * flexibility of making the priv area sticky + */ + + BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++; + BLOCK_NUM_PKTS(pbd1) = 0; + BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); + + ktime_get_real_ts64(&ts); + + h1->ts_first_pkt.ts_sec = ts.tv_sec; + h1->ts_first_pkt.ts_nsec = ts.tv_nsec; + + pkc1->pkblk_start = (char *)pbd1; + pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); + + BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv); + BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN; + + pbd1->version = pkc1->version; + pkc1->prev = pkc1->nxt_offset; + pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size; + + prb_thaw_queue(pkc1); + _prb_refresh_rx_retire_blk_timer(pkc1); + + smp_wmb(); +} + +/* + * Queue freeze logic: + * 1) Assume tp_block_nr = 8 blocks. + * 2) At time 't0', user opens Rx ring. + * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7 + * 4) user-space is either sleeping or processing block '0'. + * 5) tpacket_rcv is currently filling block '7', since there is no space left, + * it will close block-7,loop around and try to fill block '0'. + * call-flow: + * __packet_lookup_frame_in_block + * prb_retire_current_block() + * prb_dispatch_next_block() + * |->(BLOCK_STATUS == USER) evaluates to true + * 5.1) Since block-0 is currently in-use, we just freeze the queue. + * 6) Now there are two cases: + * 6.1) Link goes idle right after the queue is frozen. + * But remember, the last open_block() refreshed the timer. + * When this timer expires,it will refresh itself so that we can + * re-open block-0 in near future. + * 6.2) Link is busy and keeps on receiving packets. This is a simple + * case and __packet_lookup_frame_in_block will check if block-0 + * is free and can now be re-used. + */ +static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, + struct packet_sock *po) +{ + pkc->reset_pending_on_curr_blk = 1; + po->stats.stats3.tp_freeze_q_cnt++; +} + +#define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT)) + +/* + * If the next block is free then we will dispatch it + * and return a good offset. + * Else, we will freeze the queue. + * So, caller must check the return value. + */ +static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc, + struct packet_sock *po) +{ + struct tpacket_block_desc *pbd; + + smp_rmb(); + + /* 1. Get current block num */ + pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); + + /* 2. If this block is currently in_use then freeze the queue */ + if (TP_STATUS_USER & BLOCK_STATUS(pbd)) { + prb_freeze_queue(pkc, po); + return NULL; + } + + /* + * 3. + * open this block and return the offset where the first packet + * needs to get stored. + */ + prb_open_block(pkc, pbd); + return (void *)pkc->nxt_offset; +} + +static void prb_retire_current_block(struct tpacket_kbdq_core *pkc, + struct packet_sock *po, unsigned int status) +{ + struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); + + /* retire/close the current block */ + if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) { + /* + * Plug the case where copy_bits() is in progress on + * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't + * have space to copy the pkt in the current block and + * called prb_retire_current_block() + * + * We don't need to worry about the TMO case because + * the timer-handler already handled this case. + */ + if (!(status & TP_STATUS_BLK_TMO)) { + /* Waiting for skb_copy_bits to finish... */ + write_lock(&pkc->blk_fill_in_prog_lock); + write_unlock(&pkc->blk_fill_in_prog_lock); + } + prb_close_block(pkc, pbd, po, status); + return; + } +} + +static int prb_curr_blk_in_use(struct tpacket_block_desc *pbd) +{ + return TP_STATUS_USER & BLOCK_STATUS(pbd); +} + +static int prb_queue_frozen(struct tpacket_kbdq_core *pkc) +{ + return pkc->reset_pending_on_curr_blk; +} + +static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) + __releases(&pkc->blk_fill_in_prog_lock) +{ + struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); + + read_unlock(&pkc->blk_fill_in_prog_lock); +} + +static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc, + struct tpacket3_hdr *ppd) +{ + ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb); +} + +static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc, + struct tpacket3_hdr *ppd) +{ + ppd->hv1.tp_rxhash = 0; +} + +static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc, + struct tpacket3_hdr *ppd) +{ + if (skb_vlan_tag_present(pkc->skb)) { + ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb); + ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto); + ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; + } else { + ppd->hv1.tp_vlan_tci = 0; + ppd->hv1.tp_vlan_tpid = 0; + ppd->tp_status = TP_STATUS_AVAILABLE; + } +} + +static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc, + struct tpacket3_hdr *ppd) +{ + ppd->hv1.tp_padding = 0; + prb_fill_vlan_info(pkc, ppd); + + if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH) + prb_fill_rxhash(pkc, ppd); + else + prb_clear_rxhash(pkc, ppd); +} + +static void prb_fill_curr_block(char *curr, + struct tpacket_kbdq_core *pkc, + struct tpacket_block_desc *pbd, + unsigned int len) + __acquires(&pkc->blk_fill_in_prog_lock) +{ + struct tpacket3_hdr *ppd; + + ppd = (struct tpacket3_hdr *)curr; + ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len); + pkc->prev = curr; + pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len); + BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len); + BLOCK_NUM_PKTS(pbd) += 1; + read_lock(&pkc->blk_fill_in_prog_lock); + prb_run_all_ft_ops(pkc, ppd); +} + +/* Assumes caller has the sk->rx_queue.lock */ +static void *__packet_lookup_frame_in_block(struct packet_sock *po, + struct sk_buff *skb, + unsigned int len + ) +{ + struct tpacket_kbdq_core *pkc; + struct tpacket_block_desc *pbd; + char *curr, *end; + + pkc = GET_PBDQC_FROM_RB(&po->rx_ring); + pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); + + /* Queue is frozen when user space is lagging behind */ + if (prb_queue_frozen(pkc)) { + /* + * Check if that last block which caused the queue to freeze, + * is still in_use by user-space. + */ + if (prb_curr_blk_in_use(pbd)) { + /* Can't record this packet */ + return NULL; + } else { + /* + * Ok, the block was released by user-space. + * Now let's open that block. + * opening a block also thaws the queue. + * Thawing is a side effect. + */ + prb_open_block(pkc, pbd); + } + } + + smp_mb(); + curr = pkc->nxt_offset; + pkc->skb = skb; + end = (char *)pbd + pkc->kblk_size; + + /* first try the current block */ + if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) { + prb_fill_curr_block(curr, pkc, pbd, len); + return (void *)curr; + } + + /* Ok, close the current block */ + prb_retire_current_block(pkc, po, 0); + + /* Now, try to dispatch the next block */ + curr = (char *)prb_dispatch_next_block(pkc, po); + if (curr) { + pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc); + prb_fill_curr_block(curr, pkc, pbd, len); + return (void *)curr; + } + + /* + * No free blocks are available.user_space hasn't caught up yet. + * Queue was just frozen and now this packet will get dropped. + */ + return NULL; +} + +static void *packet_current_rx_frame(struct packet_sock *po, + struct sk_buff *skb, + int status, unsigned int len) +{ + char *curr = NULL; + switch (po->tp_version) { + case TPACKET_V1: + case TPACKET_V2: + curr = packet_lookup_frame(po, &po->rx_ring, + po->rx_ring.head, status); + return curr; + case TPACKET_V3: + return __packet_lookup_frame_in_block(po, skb, len); + default: + WARN(1, "TPACKET version not supported\n"); + BUG(); + return NULL; + } +} + +static void *prb_lookup_block(const struct packet_sock *po, + const struct packet_ring_buffer *rb, + unsigned int idx, + int status) +{ + struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); + struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx); + + if (status != BLOCK_STATUS(pbd)) + return NULL; + return pbd; +} + +static int prb_previous_blk_num(struct packet_ring_buffer *rb) +{ + unsigned int prev; + if (rb->prb_bdqc.kactive_blk_num) + prev = rb->prb_bdqc.kactive_blk_num-1; + else + prev = rb->prb_bdqc.knum_blocks-1; + return prev; +} + +/* Assumes caller has held the rx_queue.lock */ +static void *__prb_previous_block(struct packet_sock *po, + struct packet_ring_buffer *rb, + int status) +{ + unsigned int previous = prb_previous_blk_num(rb); + return prb_lookup_block(po, rb, previous, status); +} + +static void *packet_previous_rx_frame(struct packet_sock *po, + struct packet_ring_buffer *rb, + int status) +{ + if (po->tp_version <= TPACKET_V2) + return packet_previous_frame(po, rb, status); + + return __prb_previous_block(po, rb, status); +} + +static void packet_increment_rx_head(struct packet_sock *po, + struct packet_ring_buffer *rb) +{ + switch (po->tp_version) { + case TPACKET_V1: + case TPACKET_V2: + return packet_increment_head(rb); + case TPACKET_V3: + default: + WARN(1, "TPACKET version not supported.\n"); + BUG(); + return; + } +} + +static void *packet_previous_frame(struct packet_sock *po, + struct packet_ring_buffer *rb, + int status) +{ + unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max; + return packet_lookup_frame(po, rb, previous, status); +} + +static void packet_increment_head(struct packet_ring_buffer *buff) +{ + buff->head = buff->head != buff->frame_max ? buff->head+1 : 0; +} + +static void packet_inc_pending(struct packet_ring_buffer *rb) +{ + this_cpu_inc(*rb->pending_refcnt); +} + +static void packet_dec_pending(struct packet_ring_buffer *rb) +{ + this_cpu_dec(*rb->pending_refcnt); +} + +static unsigned int packet_read_pending(const struct packet_ring_buffer *rb) +{ + unsigned int refcnt = 0; + int cpu; + + /* We don't use pending refcount in rx_ring. */ + if (rb->pending_refcnt == NULL) + return 0; + + for_each_possible_cpu(cpu) + refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu); + + return refcnt; +} + +static int packet_alloc_pending(struct packet_sock *po) +{ + po->rx_ring.pending_refcnt = NULL; + + po->tx_ring.pending_refcnt = alloc_percpu(unsigned int); + if (unlikely(po->tx_ring.pending_refcnt == NULL)) + return -ENOBUFS; + + return 0; +} + +static void packet_free_pending(struct packet_sock *po) +{ + free_percpu(po->tx_ring.pending_refcnt); +} + +#define ROOM_POW_OFF 2 +#define ROOM_NONE 0x0 +#define ROOM_LOW 0x1 +#define ROOM_NORMAL 0x2 + +static bool __tpacket_has_room(const struct packet_sock *po, int pow_off) +{ + int idx, len; + + len = READ_ONCE(po->rx_ring.frame_max) + 1; + idx = READ_ONCE(po->rx_ring.head); + if (pow_off) + idx += len >> pow_off; + if (idx >= len) + idx -= len; + return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL); +} + +static bool __tpacket_v3_has_room(const struct packet_sock *po, int pow_off) +{ + int idx, len; + + len = READ_ONCE(po->rx_ring.prb_bdqc.knum_blocks); + idx = READ_ONCE(po->rx_ring.prb_bdqc.kactive_blk_num); + if (pow_off) + idx += len >> pow_off; + if (idx >= len) + idx -= len; + return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL); +} + +static int __packet_rcv_has_room(const struct packet_sock *po, + const struct sk_buff *skb) +{ + const struct sock *sk = &po->sk; + int ret = ROOM_NONE; + + if (po->prot_hook.func != tpacket_rcv) { + int rcvbuf = READ_ONCE(sk->sk_rcvbuf); + int avail = rcvbuf - atomic_read(&sk->sk_rmem_alloc) + - (skb ? skb->truesize : 0); + + if (avail > (rcvbuf >> ROOM_POW_OFF)) + return ROOM_NORMAL; + else if (avail > 0) + return ROOM_LOW; + else + return ROOM_NONE; + } + + if (po->tp_version == TPACKET_V3) { + if (__tpacket_v3_has_room(po, ROOM_POW_OFF)) + ret = ROOM_NORMAL; + else if (__tpacket_v3_has_room(po, 0)) + ret = ROOM_LOW; + } else { + if (__tpacket_has_room(po, ROOM_POW_OFF)) + ret = ROOM_NORMAL; + else if (__tpacket_has_room(po, 0)) + ret = ROOM_LOW; + } + + return ret; +} + +static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb) +{ + bool pressure; + int ret; + + ret = __packet_rcv_has_room(po, skb); + pressure = ret != ROOM_NORMAL; + + if (packet_sock_flag(po, PACKET_SOCK_PRESSURE) != pressure) + packet_sock_flag_set(po, PACKET_SOCK_PRESSURE, pressure); + + return ret; +} + +static void packet_rcv_try_clear_pressure(struct packet_sock *po) +{ + if (packet_sock_flag(po, PACKET_SOCK_PRESSURE) && + __packet_rcv_has_room(po, NULL) == ROOM_NORMAL) + packet_sock_flag_set(po, PACKET_SOCK_PRESSURE, false); +} + +static void packet_sock_destruct(struct sock *sk) +{ + skb_queue_purge(&sk->sk_error_queue); + + WARN_ON(atomic_read(&sk->sk_rmem_alloc)); + WARN_ON(refcount_read(&sk->sk_wmem_alloc)); + + if (!sock_flag(sk, SOCK_DEAD)) { + pr_err("Attempt to release alive packet socket: %p\n", sk); + return; + } +} + +static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb) +{ + u32 *history = po->rollover->history; + u32 victim, rxhash; + int i, count = 0; + + rxhash = skb_get_hash(skb); + for (i = 0; i < ROLLOVER_HLEN; i++) + if (READ_ONCE(history[i]) == rxhash) + count++; + + victim = get_random_u32_below(ROLLOVER_HLEN); + + /* Avoid dirtying the cache line if possible */ + if (READ_ONCE(history[victim]) != rxhash) + WRITE_ONCE(history[victim], rxhash); + + return count > (ROLLOVER_HLEN >> 1); +} + +static unsigned int fanout_demux_hash(struct packet_fanout *f, + struct sk_buff *skb, + unsigned int num) +{ + return reciprocal_scale(__skb_get_hash_symmetric(skb), num); +} + +static unsigned int fanout_demux_lb(struct packet_fanout *f, + struct sk_buff *skb, + unsigned int num) +{ + unsigned int val = atomic_inc_return(&f->rr_cur); + + return val % num; +} + +static unsigned int fanout_demux_cpu(struct packet_fanout *f, + struct sk_buff *skb, + unsigned int num) +{ + return smp_processor_id() % num; +} + +static unsigned int fanout_demux_rnd(struct packet_fanout *f, + struct sk_buff *skb, + unsigned int num) +{ + return get_random_u32_below(num); +} + +static unsigned int fanout_demux_rollover(struct packet_fanout *f, + struct sk_buff *skb, + unsigned int idx, bool try_self, + unsigned int num) +{ + struct packet_sock *po, *po_next, *po_skip = NULL; + unsigned int i, j, room = ROOM_NONE; + + po = pkt_sk(rcu_dereference(f->arr[idx])); + + if (try_self) { + room = packet_rcv_has_room(po, skb); + if (room == ROOM_NORMAL || + (room == ROOM_LOW && !fanout_flow_is_huge(po, skb))) + return idx; + po_skip = po; + } + + i = j = min_t(int, po->rollover->sock, num - 1); + do { + po_next = pkt_sk(rcu_dereference(f->arr[i])); + if (po_next != po_skip && + !packet_sock_flag(po_next, PACKET_SOCK_PRESSURE) && + packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) { + if (i != j) + po->rollover->sock = i; + atomic_long_inc(&po->rollover->num); + if (room == ROOM_LOW) + atomic_long_inc(&po->rollover->num_huge); + return i; + } + + if (++i == num) + i = 0; + } while (i != j); + + atomic_long_inc(&po->rollover->num_failed); + return idx; +} + +static unsigned int fanout_demux_qm(struct packet_fanout *f, + struct sk_buff *skb, + unsigned int num) +{ + return skb_get_queue_mapping(skb) % num; +} + +static unsigned int fanout_demux_bpf(struct packet_fanout *f, + struct sk_buff *skb, + unsigned int num) +{ + struct bpf_prog *prog; + unsigned int ret = 0; + + rcu_read_lock(); + prog = rcu_dereference(f->bpf_prog); + if (prog) + ret = bpf_prog_run_clear_cb(prog, skb) % num; + rcu_read_unlock(); + + return ret; +} + +static bool fanout_has_flag(struct packet_fanout *f, u16 flag) +{ + return f->flags & (flag >> 8); +} + +static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pt, struct net_device *orig_dev) +{ + struct packet_fanout *f = pt->af_packet_priv; + unsigned int num = READ_ONCE(f->num_members); + struct net *net = read_pnet(&f->net); + struct packet_sock *po; + unsigned int idx; + + if (!net_eq(dev_net(dev), net) || !num) { + kfree_skb(skb); + return 0; + } + + if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) { + skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET); + if (!skb) + return 0; + } + switch (f->type) { + case PACKET_FANOUT_HASH: + default: + idx = fanout_demux_hash(f, skb, num); + break; + case PACKET_FANOUT_LB: + idx = fanout_demux_lb(f, skb, num); + break; + case PACKET_FANOUT_CPU: + idx = fanout_demux_cpu(f, skb, num); + break; + case PACKET_FANOUT_RND: + idx = fanout_demux_rnd(f, skb, num); + break; + case PACKET_FANOUT_QM: + idx = fanout_demux_qm(f, skb, num); + break; + case PACKET_FANOUT_ROLLOVER: + idx = fanout_demux_rollover(f, skb, 0, false, num); + break; + case PACKET_FANOUT_CBPF: + case PACKET_FANOUT_EBPF: + idx = fanout_demux_bpf(f, skb, num); + break; + } + + if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER)) + idx = fanout_demux_rollover(f, skb, idx, true, num); + + po = pkt_sk(rcu_dereference(f->arr[idx])); + return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev); +} + +DEFINE_MUTEX(fanout_mutex); +EXPORT_SYMBOL_GPL(fanout_mutex); +static LIST_HEAD(fanout_list); +static u16 fanout_next_id; + +static void __fanout_link(struct sock *sk, struct packet_sock *po) +{ + struct packet_fanout *f = po->fanout; + + spin_lock(&f->lock); + rcu_assign_pointer(f->arr[f->num_members], sk); + smp_wmb(); + f->num_members++; + if (f->num_members == 1) + dev_add_pack(&f->prot_hook); + spin_unlock(&f->lock); +} + +static void __fanout_unlink(struct sock *sk, struct packet_sock *po) +{ + struct packet_fanout *f = po->fanout; + int i; + + spin_lock(&f->lock); + for (i = 0; i < f->num_members; i++) { + if (rcu_dereference_protected(f->arr[i], + lockdep_is_held(&f->lock)) == sk) + break; + } + BUG_ON(i >= f->num_members); + rcu_assign_pointer(f->arr[i], + rcu_dereference_protected(f->arr[f->num_members - 1], + lockdep_is_held(&f->lock))); + f->num_members--; + if (f->num_members == 0) + __dev_remove_pack(&f->prot_hook); + spin_unlock(&f->lock); +} + +static bool match_fanout_group(struct packet_type *ptype, struct sock *sk) +{ + if (sk->sk_family != PF_PACKET) + return false; + + return ptype->af_packet_priv == pkt_sk(sk)->fanout; +} + +static void fanout_init_data(struct packet_fanout *f) +{ + switch (f->type) { + case PACKET_FANOUT_LB: + atomic_set(&f->rr_cur, 0); + break; + case PACKET_FANOUT_CBPF: + case PACKET_FANOUT_EBPF: + RCU_INIT_POINTER(f->bpf_prog, NULL); + break; + } +} + +static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new) +{ + struct bpf_prog *old; + + spin_lock(&f->lock); + old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock)); + rcu_assign_pointer(f->bpf_prog, new); + spin_unlock(&f->lock); + + if (old) { + synchronize_net(); + bpf_prog_destroy(old); + } +} + +static int fanout_set_data_cbpf(struct packet_sock *po, sockptr_t data, + unsigned int len) +{ + struct bpf_prog *new; + struct sock_fprog fprog; + int ret; + + if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) + return -EPERM; + + ret = copy_bpf_fprog_from_user(&fprog, data, len); + if (ret) + return ret; + + ret = bpf_prog_create_from_user(&new, &fprog, NULL, false); + if (ret) + return ret; + + __fanout_set_data_bpf(po->fanout, new); + return 0; +} + +static int fanout_set_data_ebpf(struct packet_sock *po, sockptr_t data, + unsigned int len) +{ + struct bpf_prog *new; + u32 fd; + + if (sock_flag(&po->sk, SOCK_FILTER_LOCKED)) + return -EPERM; + if (len != sizeof(fd)) + return -EINVAL; + if (copy_from_sockptr(&fd, data, len)) + return -EFAULT; + + new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER); + if (IS_ERR(new)) + return PTR_ERR(new); + + __fanout_set_data_bpf(po->fanout, new); + return 0; +} + +static int fanout_set_data(struct packet_sock *po, sockptr_t data, + unsigned int len) +{ + switch (po->fanout->type) { + case PACKET_FANOUT_CBPF: + return fanout_set_data_cbpf(po, data, len); + case PACKET_FANOUT_EBPF: + return fanout_set_data_ebpf(po, data, len); + default: + return -EINVAL; + } +} + +static void fanout_release_data(struct packet_fanout *f) +{ + switch (f->type) { + case PACKET_FANOUT_CBPF: + case PACKET_FANOUT_EBPF: + __fanout_set_data_bpf(f, NULL); + } +} + +static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id) +{ + struct packet_fanout *f; + + list_for_each_entry(f, &fanout_list, list) { + if (f->id == candidate_id && + read_pnet(&f->net) == sock_net(sk)) { + return false; + } + } + return true; +} + +static bool fanout_find_new_id(struct sock *sk, u16 *new_id) +{ + u16 id = fanout_next_id; + + do { + if (__fanout_id_is_free(sk, id)) { + *new_id = id; + fanout_next_id = id + 1; + return true; + } + + id++; + } while (id != fanout_next_id); + + return false; +} + +static int fanout_add(struct sock *sk, struct fanout_args *args) +{ + struct packet_rollover *rollover = NULL; + struct packet_sock *po = pkt_sk(sk); + u16 type_flags = args->type_flags; + struct packet_fanout *f, *match; + u8 type = type_flags & 0xff; + u8 flags = type_flags >> 8; + u16 id = args->id; + int err; + + switch (type) { + case PACKET_FANOUT_ROLLOVER: + if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) + return -EINVAL; + break; + case PACKET_FANOUT_HASH: + case PACKET_FANOUT_LB: + case PACKET_FANOUT_CPU: + case PACKET_FANOUT_RND: + case PACKET_FANOUT_QM: + case PACKET_FANOUT_CBPF: + case PACKET_FANOUT_EBPF: + break; + default: + return -EINVAL; + } + + mutex_lock(&fanout_mutex); + + err = -EALREADY; + if (po->fanout) + goto out; + + if (type == PACKET_FANOUT_ROLLOVER || + (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) { + err = -ENOMEM; + rollover = kzalloc(sizeof(*rollover), GFP_KERNEL); + if (!rollover) + goto out; + atomic_long_set(&rollover->num, 0); + atomic_long_set(&rollover->num_huge, 0); + atomic_long_set(&rollover->num_failed, 0); + } + + if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) { + if (id != 0) { + err = -EINVAL; + goto out; + } + if (!fanout_find_new_id(sk, &id)) { + err = -ENOMEM; + goto out; + } + /* ephemeral flag for the first socket in the group: drop it */ + flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8); + } + + match = NULL; + list_for_each_entry(f, &fanout_list, list) { + if (f->id == id && + read_pnet(&f->net) == sock_net(sk)) { + match = f; + break; + } + } + err = -EINVAL; + if (match) { + if (match->flags != flags) + goto out; + if (args->max_num_members && + args->max_num_members != match->max_num_members) + goto out; + } else { + if (args->max_num_members > PACKET_FANOUT_MAX) + goto out; + if (!args->max_num_members) + /* legacy PACKET_FANOUT_MAX */ + args->max_num_members = 256; + err = -ENOMEM; + match = kvzalloc(struct_size(match, arr, args->max_num_members), + GFP_KERNEL); + if (!match) + goto out; + write_pnet(&match->net, sock_net(sk)); + match->id = id; + match->type = type; + match->flags = flags; + INIT_LIST_HEAD(&match->list); + spin_lock_init(&match->lock); + refcount_set(&match->sk_ref, 0); + fanout_init_data(match); + match->prot_hook.type = po->prot_hook.type; + match->prot_hook.dev = po->prot_hook.dev; + match->prot_hook.func = packet_rcv_fanout; + match->prot_hook.af_packet_priv = match; + match->prot_hook.af_packet_net = read_pnet(&match->net); + match->prot_hook.id_match = match_fanout_group; + match->max_num_members = args->max_num_members; + match->prot_hook.ignore_outgoing = type_flags & PACKET_FANOUT_FLAG_IGNORE_OUTGOING; + list_add(&match->list, &fanout_list); + } + err = -EINVAL; + + spin_lock(&po->bind_lock); + if (packet_sock_flag(po, PACKET_SOCK_RUNNING) && + match->type == type && + match->prot_hook.type == po->prot_hook.type && + match->prot_hook.dev == po->prot_hook.dev) { + err = -ENOSPC; + if (refcount_read(&match->sk_ref) < match->max_num_members) { + __dev_remove_pack(&po->prot_hook); + + /* Paired with packet_setsockopt(PACKET_FANOUT_DATA) */ + WRITE_ONCE(po->fanout, match); + + po->rollover = rollover; + rollover = NULL; + refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1); + __fanout_link(sk, po); + err = 0; + } + } + spin_unlock(&po->bind_lock); + + if (err && !refcount_read(&match->sk_ref)) { + list_del(&match->list); + kvfree(match); + } + +out: + kfree(rollover); + mutex_unlock(&fanout_mutex); + return err; +} + +/* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes + * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout. + * It is the responsibility of the caller to call fanout_release_data() and + * free the returned packet_fanout (after synchronize_net()) + */ +static struct packet_fanout *fanout_release(struct sock *sk) +{ + struct packet_sock *po = pkt_sk(sk); + struct packet_fanout *f; + + mutex_lock(&fanout_mutex); + f = po->fanout; + if (f) { + po->fanout = NULL; + + if (refcount_dec_and_test(&f->sk_ref)) + list_del(&f->list); + else + f = NULL; + } + mutex_unlock(&fanout_mutex); + + return f; +} + +static bool packet_extra_vlan_len_allowed(const struct net_device *dev, + struct sk_buff *skb) +{ + /* Earlier code assumed this would be a VLAN pkt, double-check + * this now that we have the actual packet in hand. We can only + * do this check on Ethernet devices. + */ + if (unlikely(dev->type != ARPHRD_ETHER)) + return false; + + skb_reset_mac_header(skb); + return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q)); +} + +static const struct proto_ops packet_ops; + +static const struct proto_ops packet_ops_spkt; + +static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pt, struct net_device *orig_dev) +{ + struct sock *sk; + struct sockaddr_pkt *spkt; + + /* + * When we registered the protocol we saved the socket in the data + * field for just this event. + */ + + sk = pt->af_packet_priv; + + /* + * Yank back the headers [hope the device set this + * right or kerboom...] + * + * Incoming packets have ll header pulled, + * push it back. + * + * For outgoing ones skb->data == skb_mac_header(skb) + * so that this procedure is noop. + */ + + if (skb->pkt_type == PACKET_LOOPBACK) + goto out; + + if (!net_eq(dev_net(dev), sock_net(sk))) + goto out; + + skb = skb_share_check(skb, GFP_ATOMIC); + if (skb == NULL) + goto oom; + + /* drop any routing info */ + skb_dst_drop(skb); + + /* drop conntrack reference */ + nf_reset_ct(skb); + + spkt = &PACKET_SKB_CB(skb)->sa.pkt; + + skb_push(skb, skb->data - skb_mac_header(skb)); + + /* + * The SOCK_PACKET socket receives _all_ frames. + */ + + spkt->spkt_family = dev->type; + strscpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device)); + spkt->spkt_protocol = skb->protocol; + + /* + * Charge the memory to the socket. This is done specifically + * to prevent sockets using all the memory up. + */ + + if (sock_queue_rcv_skb(sk, skb) == 0) + return 0; + +out: + kfree_skb(skb); +oom: + return 0; +} + +static void packet_parse_headers(struct sk_buff *skb, struct socket *sock) +{ + int depth; + + if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) && + sock->type == SOCK_RAW) { + skb_reset_mac_header(skb); + skb->protocol = dev_parse_header_protocol(skb); + } + + /* Move network header to the right position for VLAN tagged packets */ + if (likely(skb->dev->type == ARPHRD_ETHER) && + eth_type_vlan(skb->protocol) && + vlan_get_protocol_and_depth(skb, skb->protocol, &depth) != 0) + skb_set_network_header(skb, depth); + + skb_probe_transport_header(skb); +} + +/* + * Output a raw packet to a device layer. This bypasses all the other + * protocol layers and you must therefore supply it with a complete frame + */ + +static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg, + size_t len) +{ + struct sock *sk = sock->sk; + DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name); + struct sk_buff *skb = NULL; + struct net_device *dev; + struct sockcm_cookie sockc; + __be16 proto = 0; + int err; + int extra_len = 0; + + /* + * Get and verify the address. + */ + + if (saddr) { + if (msg->msg_namelen < sizeof(struct sockaddr)) + return -EINVAL; + if (msg->msg_namelen == sizeof(struct sockaddr_pkt)) + proto = saddr->spkt_protocol; + } else + return -ENOTCONN; /* SOCK_PACKET must be sent giving an address */ + + /* + * Find the device first to size check it + */ + + saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0; +retry: + rcu_read_lock(); + dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device); + err = -ENODEV; + if (dev == NULL) + goto out_unlock; + + err = -ENETDOWN; + if (!(dev->flags & IFF_UP)) + goto out_unlock; + + /* + * You may not queue a frame bigger than the mtu. This is the lowest level + * raw protocol and you must do your own fragmentation at this level. + */ + + if (unlikely(sock_flag(sk, SOCK_NOFCS))) { + if (!netif_supports_nofcs(dev)) { + err = -EPROTONOSUPPORT; + goto out_unlock; + } + extra_len = 4; /* We're doing our own CRC */ + } + + err = -EMSGSIZE; + if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len) + goto out_unlock; + + if (!skb) { + size_t reserved = LL_RESERVED_SPACE(dev); + int tlen = dev->needed_tailroom; + unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0; + + rcu_read_unlock(); + skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL); + if (skb == NULL) + return -ENOBUFS; + /* FIXME: Save some space for broken drivers that write a hard + * header at transmission time by themselves. PPP is the notable + * one here. This should really be fixed at the driver level. + */ + skb_reserve(skb, reserved); + skb_reset_network_header(skb); + + /* Try to align data part correctly */ + if (hhlen) { + skb->data -= hhlen; + skb->tail -= hhlen; + if (len < hhlen) + skb_reset_network_header(skb); + } + err = memcpy_from_msg(skb_put(skb, len), msg, len); + if (err) + goto out_free; + goto retry; + } + + if (!dev_validate_header(dev, skb->data, len) || !skb->len) { + err = -EINVAL; + goto out_unlock; + } + if (len > (dev->mtu + dev->hard_header_len + extra_len) && + !packet_extra_vlan_len_allowed(dev, skb)) { + err = -EMSGSIZE; + goto out_unlock; + } + + sockcm_init(&sockc, sk); + if (msg->msg_controllen) { + err = sock_cmsg_send(sk, msg, &sockc); + if (unlikely(err)) + goto out_unlock; + } + + skb->protocol = proto; + skb->dev = dev; + skb->priority = READ_ONCE(sk->sk_priority); + skb->mark = READ_ONCE(sk->sk_mark); + skb->tstamp = sockc.transmit_time; + + skb_setup_tx_timestamp(skb, sockc.tsflags); + + if (unlikely(extra_len == 4)) + skb->no_fcs = 1; + + packet_parse_headers(skb, sock); + + dev_queue_xmit(skb); + rcu_read_unlock(); + return len; + +out_unlock: + rcu_read_unlock(); +out_free: + kfree_skb(skb); + return err; +} + +static unsigned int run_filter(struct sk_buff *skb, + const struct sock *sk, + unsigned int res) +{ + struct sk_filter *filter; + + rcu_read_lock(); + filter = rcu_dereference(sk->sk_filter); + if (filter != NULL) + res = bpf_prog_run_clear_cb(filter->prog, skb); + rcu_read_unlock(); + + return res; +} + +static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb, + size_t *len, int vnet_hdr_sz) +{ + struct virtio_net_hdr_mrg_rxbuf vnet_hdr = { .num_buffers = 0 }; + + if (*len < vnet_hdr_sz) + return -EINVAL; + *len -= vnet_hdr_sz; + + if (virtio_net_hdr_from_skb(skb, (struct virtio_net_hdr *)&vnet_hdr, vio_le(), true, 0)) + return -EINVAL; + + return memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_sz); +} + +/* + * This function makes lazy skb cloning in hope that most of packets + * are discarded by BPF. + * + * Note tricky part: we DO mangle shared skb! skb->data, skb->len + * and skb->cb are mangled. It works because (and until) packets + * falling here are owned by current CPU. Output packets are cloned + * by dev_queue_xmit_nit(), input packets are processed by net_bh + * sequentially, so that if we return skb to original state on exit, + * we will not harm anyone. + */ + +static int packet_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pt, struct net_device *orig_dev) +{ + struct sock *sk; + struct sockaddr_ll *sll; + struct packet_sock *po; + u8 *skb_head = skb->data; + int skb_len = skb->len; + unsigned int snaplen, res; + bool is_drop_n_account = false; + + if (skb->pkt_type == PACKET_LOOPBACK) + goto drop; + + sk = pt->af_packet_priv; + po = pkt_sk(sk); + + if (!net_eq(dev_net(dev), sock_net(sk))) + goto drop; + + skb->dev = dev; + + if (dev_has_header(dev)) { + /* The device has an explicit notion of ll header, + * exported to higher levels. + * + * Otherwise, the device hides details of its frame + * structure, so that corresponding packet head is + * never delivered to user. + */ + if (sk->sk_type != SOCK_DGRAM) + skb_push(skb, skb->data - skb_mac_header(skb)); + else if (skb->pkt_type == PACKET_OUTGOING) { + /* Special case: outgoing packets have ll header at head */ + skb_pull(skb, skb_network_offset(skb)); + } + } + + snaplen = skb->len; + + res = run_filter(skb, sk, snaplen); + if (!res) + goto drop_n_restore; + if (snaplen > res) + snaplen = res; + + if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) + goto drop_n_acct; + + if (skb_shared(skb)) { + struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); + if (nskb == NULL) + goto drop_n_acct; + + if (skb_head != skb->data) { + skb->data = skb_head; + skb->len = skb_len; + } + consume_skb(skb); + skb = nskb; + } + + sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8); + + sll = &PACKET_SKB_CB(skb)->sa.ll; + sll->sll_hatype = dev->type; + sll->sll_pkttype = skb->pkt_type; + if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) + sll->sll_ifindex = orig_dev->ifindex; + else + sll->sll_ifindex = dev->ifindex; + + sll->sll_halen = dev_parse_header(skb, sll->sll_addr); + + /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg(). + * Use their space for storing the original skb length. + */ + PACKET_SKB_CB(skb)->sa.origlen = skb->len; + + if (pskb_trim(skb, snaplen)) + goto drop_n_acct; + + skb_set_owner_r(skb, sk); + skb->dev = NULL; + skb_dst_drop(skb); + + /* drop conntrack reference */ + nf_reset_ct(skb); + + spin_lock(&sk->sk_receive_queue.lock); + po->stats.stats1.tp_packets++; + sock_skb_set_dropcount(sk, skb); + skb_clear_delivery_time(skb); + __skb_queue_tail(&sk->sk_receive_queue, skb); + spin_unlock(&sk->sk_receive_queue.lock); + sk->sk_data_ready(sk); + return 0; + +drop_n_acct: + is_drop_n_account = true; + atomic_inc(&po->tp_drops); + atomic_inc(&sk->sk_drops); + +drop_n_restore: + if (skb_head != skb->data && skb_shared(skb)) { + skb->data = skb_head; + skb->len = skb_len; + } +drop: + if (!is_drop_n_account) + consume_skb(skb); + else + kfree_skb(skb); + return 0; +} + +static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pt, struct net_device *orig_dev) +{ + struct sock *sk; + struct packet_sock *po; + struct sockaddr_ll *sll; + union tpacket_uhdr h; + u8 *skb_head = skb->data; + int skb_len = skb->len; + unsigned int snaplen, res; + unsigned long status = TP_STATUS_USER; + unsigned short macoff, hdrlen; + unsigned int netoff; + struct sk_buff *copy_skb = NULL; + struct timespec64 ts; + __u32 ts_status; + bool is_drop_n_account = false; + unsigned int slot_id = 0; + int vnet_hdr_sz = 0; + + /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. + * We may add members to them until current aligned size without forcing + * userspace to call getsockopt(..., PACKET_HDRLEN, ...). + */ + BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32); + BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48); + + if (skb->pkt_type == PACKET_LOOPBACK) + goto drop; + + sk = pt->af_packet_priv; + po = pkt_sk(sk); + + if (!net_eq(dev_net(dev), sock_net(sk))) + goto drop; + + if (dev_has_header(dev)) { + if (sk->sk_type != SOCK_DGRAM) + skb_push(skb, skb->data - skb_mac_header(skb)); + else if (skb->pkt_type == PACKET_OUTGOING) { + /* Special case: outgoing packets have ll header at head */ + skb_pull(skb, skb_network_offset(skb)); + } + } + + snaplen = skb->len; + + res = run_filter(skb, sk, snaplen); + if (!res) + goto drop_n_restore; + + /* If we are flooded, just give up */ + if (__packet_rcv_has_room(po, skb) == ROOM_NONE) { + atomic_inc(&po->tp_drops); + goto drop_n_restore; + } + + if (skb->ip_summed == CHECKSUM_PARTIAL) + status |= TP_STATUS_CSUMNOTREADY; + else if (skb->pkt_type != PACKET_OUTGOING && + skb_csum_unnecessary(skb)) + status |= TP_STATUS_CSUM_VALID; + if (skb_is_gso(skb) && skb_is_gso_tcp(skb)) + status |= TP_STATUS_GSO_TCP; + + if (snaplen > res) + snaplen = res; + + if (sk->sk_type == SOCK_DGRAM) { + macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 + + po->tp_reserve; + } else { + unsigned int maclen = skb_network_offset(skb); + netoff = TPACKET_ALIGN(po->tp_hdrlen + + (maclen < 16 ? 16 : maclen)) + + po->tp_reserve; + vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); + if (vnet_hdr_sz) + netoff += vnet_hdr_sz; + macoff = netoff - maclen; + } + if (netoff > USHRT_MAX) { + atomic_inc(&po->tp_drops); + goto drop_n_restore; + } + if (po->tp_version <= TPACKET_V2) { + if (macoff + snaplen > po->rx_ring.frame_size) { + if (po->copy_thresh && + atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) { + if (skb_shared(skb)) { + copy_skb = skb_clone(skb, GFP_ATOMIC); + } else { + copy_skb = skb_get(skb); + skb_head = skb->data; + } + if (copy_skb) { + memset(&PACKET_SKB_CB(copy_skb)->sa.ll, 0, + sizeof(PACKET_SKB_CB(copy_skb)->sa.ll)); + skb_set_owner_r(copy_skb, sk); + } + } + snaplen = po->rx_ring.frame_size - macoff; + if ((int)snaplen < 0) { + snaplen = 0; + vnet_hdr_sz = 0; + } + } + } else if (unlikely(macoff + snaplen > + GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) { + u32 nval; + + nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff; + pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n", + snaplen, nval, macoff); + snaplen = nval; + if (unlikely((int)snaplen < 0)) { + snaplen = 0; + macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len; + vnet_hdr_sz = 0; + } + } + spin_lock(&sk->sk_receive_queue.lock); + h.raw = packet_current_rx_frame(po, skb, + TP_STATUS_KERNEL, (macoff+snaplen)); + if (!h.raw) + goto drop_n_account; + + if (po->tp_version <= TPACKET_V2) { + slot_id = po->rx_ring.head; + if (test_bit(slot_id, po->rx_ring.rx_owner_map)) + goto drop_n_account; + __set_bit(slot_id, po->rx_ring.rx_owner_map); + } + + if (vnet_hdr_sz && + virtio_net_hdr_from_skb(skb, h.raw + macoff - + sizeof(struct virtio_net_hdr), + vio_le(), true, 0)) { + if (po->tp_version == TPACKET_V3) + prb_clear_blk_fill_status(&po->rx_ring); + goto drop_n_account; + } + + if (po->tp_version <= TPACKET_V2) { + packet_increment_rx_head(po, &po->rx_ring); + /* + * LOSING will be reported till you read the stats, + * because it's COR - Clear On Read. + * Anyways, moving it for V1/V2 only as V3 doesn't need this + * at packet level. + */ + if (atomic_read(&po->tp_drops)) + status |= TP_STATUS_LOSING; + } + + po->stats.stats1.tp_packets++; + if (copy_skb) { + status |= TP_STATUS_COPY; + skb_clear_delivery_time(copy_skb); + __skb_queue_tail(&sk->sk_receive_queue, copy_skb); + } + spin_unlock(&sk->sk_receive_queue.lock); + + skb_copy_bits(skb, 0, h.raw + macoff, snaplen); + + /* Always timestamp; prefer an existing software timestamp taken + * closer to the time of capture. + */ + ts_status = tpacket_get_timestamp(skb, &ts, + READ_ONCE(po->tp_tstamp) | + SOF_TIMESTAMPING_SOFTWARE); + if (!ts_status) + ktime_get_real_ts64(&ts); + + status |= ts_status; + + switch (po->tp_version) { + case TPACKET_V1: + h.h1->tp_len = skb->len; + h.h1->tp_snaplen = snaplen; + h.h1->tp_mac = macoff; + h.h1->tp_net = netoff; + h.h1->tp_sec = ts.tv_sec; + h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC; + hdrlen = sizeof(*h.h1); + break; + case TPACKET_V2: + h.h2->tp_len = skb->len; + h.h2->tp_snaplen = snaplen; + h.h2->tp_mac = macoff; + h.h2->tp_net = netoff; + h.h2->tp_sec = ts.tv_sec; + h.h2->tp_nsec = ts.tv_nsec; + if (skb_vlan_tag_present(skb)) { + h.h2->tp_vlan_tci = skb_vlan_tag_get(skb); + h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto); + status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; + } else { + h.h2->tp_vlan_tci = 0; + h.h2->tp_vlan_tpid = 0; + } + memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding)); + hdrlen = sizeof(*h.h2); + break; + case TPACKET_V3: + /* tp_nxt_offset,vlan are already populated above. + * So DONT clear those fields here + */ + h.h3->tp_status |= status; + h.h3->tp_len = skb->len; + h.h3->tp_snaplen = snaplen; + h.h3->tp_mac = macoff; + h.h3->tp_net = netoff; + h.h3->tp_sec = ts.tv_sec; + h.h3->tp_nsec = ts.tv_nsec; + memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding)); + hdrlen = sizeof(*h.h3); + break; + default: + BUG(); + } + + sll = h.raw + TPACKET_ALIGN(hdrlen); + sll->sll_halen = dev_parse_header(skb, sll->sll_addr); + sll->sll_family = AF_PACKET; + sll->sll_hatype = dev->type; + sll->sll_protocol = skb->protocol; + sll->sll_pkttype = skb->pkt_type; + if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV))) + sll->sll_ifindex = orig_dev->ifindex; + else + sll->sll_ifindex = dev->ifindex; + + smp_mb(); + +#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 + if (po->tp_version <= TPACKET_V2) { + u8 *start, *end; + + end = (u8 *) PAGE_ALIGN((unsigned long) h.raw + + macoff + snaplen); + + for (start = h.raw; start < end; start += PAGE_SIZE) + flush_dcache_page(pgv_to_page(start)); + } + smp_wmb(); +#endif + + if (po->tp_version <= TPACKET_V2) { + spin_lock(&sk->sk_receive_queue.lock); + __packet_set_status(po, h.raw, status); + __clear_bit(slot_id, po->rx_ring.rx_owner_map); + spin_unlock(&sk->sk_receive_queue.lock); + sk->sk_data_ready(sk); + } else if (po->tp_version == TPACKET_V3) { + prb_clear_blk_fill_status(&po->rx_ring); + } + +drop_n_restore: + if (skb_head != skb->data && skb_shared(skb)) { + skb->data = skb_head; + skb->len = skb_len; + } +drop: + if (!is_drop_n_account) + consume_skb(skb); + else + kfree_skb(skb); + return 0; + +drop_n_account: + spin_unlock(&sk->sk_receive_queue.lock); + atomic_inc(&po->tp_drops); + is_drop_n_account = true; + + sk->sk_data_ready(sk); + kfree_skb(copy_skb); + goto drop_n_restore; +} + +static void tpacket_destruct_skb(struct sk_buff *skb) +{ + struct packet_sock *po = pkt_sk(skb->sk); + + if (likely(po->tx_ring.pg_vec)) { + void *ph; + __u32 ts; + + ph = skb_zcopy_get_nouarg(skb); + packet_dec_pending(&po->tx_ring); + + ts = __packet_set_timestamp(po, ph, skb); + __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts); + + if (!packet_read_pending(&po->tx_ring)) + complete(&po->skb_completion); + } + + sock_wfree(skb); +} + +static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len) +{ + if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && + (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + + __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 > + __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len))) + vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(), + __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) + + __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2); + + if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len) + return -EINVAL; + + return 0; +} + +static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len, + struct virtio_net_hdr *vnet_hdr, int vnet_hdr_sz) +{ + int ret; + + if (*len < vnet_hdr_sz) + return -EINVAL; + *len -= vnet_hdr_sz; + + if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter)) + return -EFAULT; + + ret = __packet_snd_vnet_parse(vnet_hdr, *len); + if (ret) + return ret; + + /* move iter to point to the start of mac header */ + if (vnet_hdr_sz != sizeof(struct virtio_net_hdr)) + iov_iter_advance(&msg->msg_iter, vnet_hdr_sz - sizeof(struct virtio_net_hdr)); + + return 0; +} + +static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, + void *frame, struct net_device *dev, void *data, int tp_len, + __be16 proto, unsigned char *addr, int hlen, int copylen, + const struct sockcm_cookie *sockc) +{ + union tpacket_uhdr ph; + int to_write, offset, len, nr_frags, len_max; + struct socket *sock = po->sk.sk_socket; + struct page *page; + int err; + + ph.raw = frame; + + skb->protocol = proto; + skb->dev = dev; + skb->priority = READ_ONCE(po->sk.sk_priority); + skb->mark = READ_ONCE(po->sk.sk_mark); + skb->tstamp = sockc->transmit_time; + skb_setup_tx_timestamp(skb, sockc->tsflags); + skb_zcopy_set_nouarg(skb, ph.raw); + + skb_reserve(skb, hlen); + skb_reset_network_header(skb); + + to_write = tp_len; + + if (sock->type == SOCK_DGRAM) { + err = dev_hard_header(skb, dev, ntohs(proto), addr, + NULL, tp_len); + if (unlikely(err < 0)) + return -EINVAL; + } else if (copylen) { + int hdrlen = min_t(int, copylen, tp_len); + + skb_push(skb, dev->hard_header_len); + skb_put(skb, copylen - dev->hard_header_len); + err = skb_store_bits(skb, 0, data, hdrlen); + if (unlikely(err)) + return err; + if (!dev_validate_header(dev, skb->data, hdrlen)) + return -EINVAL; + + data += hdrlen; + to_write -= hdrlen; + } + + offset = offset_in_page(data); + len_max = PAGE_SIZE - offset; + len = ((to_write > len_max) ? len_max : to_write); + + skb->data_len = to_write; + skb->len += to_write; + skb->truesize += to_write; + refcount_add(to_write, &po->sk.sk_wmem_alloc); + + while (likely(to_write)) { + nr_frags = skb_shinfo(skb)->nr_frags; + + if (unlikely(nr_frags >= MAX_SKB_FRAGS)) { + pr_err("Packet exceed the number of skb frags(%u)\n", + (unsigned int)MAX_SKB_FRAGS); + return -EFAULT; + } + + page = pgv_to_page(data); + data += len; + flush_dcache_page(page); + get_page(page); + skb_fill_page_desc(skb, nr_frags, page, offset, len); + to_write -= len; + offset = 0; + len_max = PAGE_SIZE; + len = ((to_write > len_max) ? len_max : to_write); + } + + packet_parse_headers(skb, sock); + + return tp_len; +} + +static int tpacket_parse_header(struct packet_sock *po, void *frame, + int size_max, void **data) +{ + union tpacket_uhdr ph; + int tp_len, off; + + ph.raw = frame; + + switch (po->tp_version) { + case TPACKET_V3: + if (ph.h3->tp_next_offset != 0) { + pr_warn_once("variable sized slot not supported"); + return -EINVAL; + } + tp_len = ph.h3->tp_len; + break; + case TPACKET_V2: + tp_len = ph.h2->tp_len; + break; + default: + tp_len = ph.h1->tp_len; + break; + } + if (unlikely(tp_len > size_max)) { + pr_err("packet size is too long (%d > %d)\n", tp_len, size_max); + return -EMSGSIZE; + } + + if (unlikely(packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF))) { + int off_min, off_max; + + off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); + off_max = po->tx_ring.frame_size - tp_len; + if (po->sk.sk_type == SOCK_DGRAM) { + switch (po->tp_version) { + case TPACKET_V3: + off = ph.h3->tp_net; + break; + case TPACKET_V2: + off = ph.h2->tp_net; + break; + default: + off = ph.h1->tp_net; + break; + } + } else { + switch (po->tp_version) { + case TPACKET_V3: + off = ph.h3->tp_mac; + break; + case TPACKET_V2: + off = ph.h2->tp_mac; + break; + default: + off = ph.h1->tp_mac; + break; + } + } + if (unlikely((off < off_min) || (off_max < off))) + return -EINVAL; + } else { + off = po->tp_hdrlen - sizeof(struct sockaddr_ll); + } + + *data = frame + off; + return tp_len; +} + +static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) +{ + struct sk_buff *skb = NULL; + struct net_device *dev; + struct virtio_net_hdr *vnet_hdr = NULL; + struct sockcm_cookie sockc; + __be16 proto; + int err, reserve = 0; + void *ph; + DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); + bool need_wait = !(msg->msg_flags & MSG_DONTWAIT); + int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); + unsigned char *addr = NULL; + int tp_len, size_max; + void *data; + int len_sum = 0; + int status = TP_STATUS_AVAILABLE; + int hlen, tlen, copylen = 0; + long timeo = 0; + + mutex_lock(&po->pg_vec_lock); + + /* packet_sendmsg() check on tx_ring.pg_vec was lockless, + * we need to confirm it under protection of pg_vec_lock. + */ + if (unlikely(!po->tx_ring.pg_vec)) { + err = -EBUSY; + goto out; + } + if (likely(saddr == NULL)) { + dev = packet_cached_dev_get(po); + proto = READ_ONCE(po->num); + } else { + err = -EINVAL; + if (msg->msg_namelen < sizeof(struct sockaddr_ll)) + goto out; + if (msg->msg_namelen < (saddr->sll_halen + + offsetof(struct sockaddr_ll, + sll_addr))) + goto out; + proto = saddr->sll_protocol; + dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex); + if (po->sk.sk_socket->type == SOCK_DGRAM) { + if (dev && msg->msg_namelen < dev->addr_len + + offsetof(struct sockaddr_ll, sll_addr)) + goto out_put; + addr = saddr->sll_addr; + } + } + + err = -ENXIO; + if (unlikely(dev == NULL)) + goto out; + err = -ENETDOWN; + if (unlikely(!(dev->flags & IFF_UP))) + goto out_put; + + sockcm_init(&sockc, &po->sk); + if (msg->msg_controllen) { + err = sock_cmsg_send(&po->sk, msg, &sockc); + if (unlikely(err)) + goto out_put; + } + + if (po->sk.sk_socket->type == SOCK_RAW) + reserve = dev->hard_header_len; + size_max = po->tx_ring.frame_size + - (po->tp_hdrlen - sizeof(struct sockaddr_ll)); + + if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !vnet_hdr_sz) + size_max = dev->mtu + reserve + VLAN_HLEN; + + reinit_completion(&po->skb_completion); + + do { + ph = packet_current_frame(po, &po->tx_ring, + TP_STATUS_SEND_REQUEST); + if (unlikely(ph == NULL)) { + if (need_wait && skb) { + timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT); + timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo); + if (timeo <= 0) { + err = !timeo ? -ETIMEDOUT : -ERESTARTSYS; + goto out_put; + } + } + /* check for additional frames */ + continue; + } + + skb = NULL; + tp_len = tpacket_parse_header(po, ph, size_max, &data); + if (tp_len < 0) + goto tpacket_error; + + status = TP_STATUS_SEND_REQUEST; + hlen = LL_RESERVED_SPACE(dev); + tlen = dev->needed_tailroom; + if (vnet_hdr_sz) { + vnet_hdr = data; + data += vnet_hdr_sz; + tp_len -= vnet_hdr_sz; + if (tp_len < 0 || + __packet_snd_vnet_parse(vnet_hdr, tp_len)) { + tp_len = -EINVAL; + goto tpacket_error; + } + copylen = __virtio16_to_cpu(vio_le(), + vnet_hdr->hdr_len); + } + copylen = max_t(int, copylen, dev->hard_header_len); + skb = sock_alloc_send_skb(&po->sk, + hlen + tlen + sizeof(struct sockaddr_ll) + + (copylen - dev->hard_header_len), + !need_wait, &err); + + if (unlikely(skb == NULL)) { + /* we assume the socket was initially writeable ... */ + if (likely(len_sum > 0)) + err = len_sum; + goto out_status; + } + tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto, + addr, hlen, copylen, &sockc); + if (likely(tp_len >= 0) && + tp_len > dev->mtu + reserve && + !vnet_hdr_sz && + !packet_extra_vlan_len_allowed(dev, skb)) + tp_len = -EMSGSIZE; + + if (unlikely(tp_len < 0)) { +tpacket_error: + if (packet_sock_flag(po, PACKET_SOCK_TP_LOSS)) { + __packet_set_status(po, ph, + TP_STATUS_AVAILABLE); + packet_increment_head(&po->tx_ring); + kfree_skb(skb); + continue; + } else { + status = TP_STATUS_WRONG_FORMAT; + err = tp_len; + goto out_status; + } + } + + if (vnet_hdr_sz) { + if (virtio_net_hdr_to_skb(skb, vnet_hdr, vio_le())) { + tp_len = -EINVAL; + goto tpacket_error; + } + virtio_net_hdr_set_proto(skb, vnet_hdr); + } + + skb->destructor = tpacket_destruct_skb; + __packet_set_status(po, ph, TP_STATUS_SENDING); + packet_inc_pending(&po->tx_ring); + + status = TP_STATUS_SEND_REQUEST; + err = packet_xmit(po, skb); + if (unlikely(err != 0)) { + if (err > 0) + err = net_xmit_errno(err); + if (err && __packet_get_status(po, ph) == + TP_STATUS_AVAILABLE) { + /* skb was destructed already */ + skb = NULL; + goto out_status; + } + /* + * skb was dropped but not destructed yet; + * let's treat it like congestion or err < 0 + */ + err = 0; + } + packet_increment_head(&po->tx_ring); + len_sum += tp_len; + } while (likely((ph != NULL) || + /* Note: packet_read_pending() might be slow if we have + * to call it as it's per_cpu variable, but in fast-path + * we already short-circuit the loop with the first + * condition, and luckily don't have to go that path + * anyway. + */ + (need_wait && packet_read_pending(&po->tx_ring)))); + + err = len_sum; + goto out_put; + +out_status: + __packet_set_status(po, ph, status); + kfree_skb(skb); +out_put: + dev_put(dev); +out: + mutex_unlock(&po->pg_vec_lock); + return err; +} + +static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad, + size_t reserve, size_t len, + size_t linear, int noblock, + int *err) +{ + struct sk_buff *skb; + + /* Under a page? Don't bother with paged skb. */ + if (prepad + len < PAGE_SIZE || !linear) + linear = len; + + if (len - linear > MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) + linear = len - MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER); + skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, + err, PAGE_ALLOC_COSTLY_ORDER); + if (!skb) + return NULL; + + skb_reserve(skb, reserve); + skb_put(skb, linear); + skb->data_len = len - linear; + skb->len += len - linear; + + return skb; +} + +static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) +{ + struct sock *sk = sock->sk; + DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name); + struct sk_buff *skb; + struct net_device *dev; + __be16 proto; + unsigned char *addr = NULL; + int err, reserve = 0; + struct sockcm_cookie sockc; + struct virtio_net_hdr vnet_hdr = { 0 }; + int offset = 0; + struct packet_sock *po = pkt_sk(sk); + int vnet_hdr_sz = READ_ONCE(po->vnet_hdr_sz); + int hlen, tlen, linear; + int extra_len = 0; + + /* + * Get and verify the address. + */ + + if (likely(saddr == NULL)) { + dev = packet_cached_dev_get(po); + proto = READ_ONCE(po->num); + } else { + err = -EINVAL; + if (msg->msg_namelen < sizeof(struct sockaddr_ll)) + goto out; + if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) + goto out; + proto = saddr->sll_protocol; + dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex); + if (sock->type == SOCK_DGRAM) { + if (dev && msg->msg_namelen < dev->addr_len + + offsetof(struct sockaddr_ll, sll_addr)) + goto out_unlock; + addr = saddr->sll_addr; + } + } + + err = -ENXIO; + if (unlikely(dev == NULL)) + goto out_unlock; + err = -ENETDOWN; + if (unlikely(!(dev->flags & IFF_UP))) + goto out_unlock; + + sockcm_init(&sockc, sk); + sockc.mark = READ_ONCE(sk->sk_mark); + if (msg->msg_controllen) { + err = sock_cmsg_send(sk, msg, &sockc); + if (unlikely(err)) + goto out_unlock; + } + + if (sock->type == SOCK_RAW) + reserve = dev->hard_header_len; + if (vnet_hdr_sz) { + err = packet_snd_vnet_parse(msg, &len, &vnet_hdr, vnet_hdr_sz); + if (err) + goto out_unlock; + } + + if (unlikely(sock_flag(sk, SOCK_NOFCS))) { + if (!netif_supports_nofcs(dev)) { + err = -EPROTONOSUPPORT; + goto out_unlock; + } + extra_len = 4; /* We're doing our own CRC */ + } + + err = -EMSGSIZE; + if (!vnet_hdr.gso_type && + (len > dev->mtu + reserve + VLAN_HLEN + extra_len)) + goto out_unlock; + + err = -ENOBUFS; + hlen = LL_RESERVED_SPACE(dev); + tlen = dev->needed_tailroom; + linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len); + linear = max(linear, min_t(int, len, dev->hard_header_len)); + skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear, + msg->msg_flags & MSG_DONTWAIT, &err); + if (skb == NULL) + goto out_unlock; + + skb_reset_network_header(skb); + + err = -EINVAL; + if (sock->type == SOCK_DGRAM) { + offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); + if (unlikely(offset < 0)) + goto out_free; + } else if (reserve) { + skb_reserve(skb, -reserve); + if (len < reserve + sizeof(struct ipv6hdr) && + dev->min_header_len != dev->hard_header_len) + skb_reset_network_header(skb); + } + + /* Returns -EFAULT on error */ + err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len); + if (err) + goto out_free; + + if ((sock->type == SOCK_RAW && + !dev_validate_header(dev, skb->data, len)) || !skb->len) { + err = -EINVAL; + goto out_free; + } + + skb_setup_tx_timestamp(skb, sockc.tsflags); + + if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) && + !packet_extra_vlan_len_allowed(dev, skb)) { + err = -EMSGSIZE; + goto out_free; + } + + skb->protocol = proto; + skb->dev = dev; + skb->priority = READ_ONCE(sk->sk_priority); + skb->mark = sockc.mark; + skb->tstamp = sockc.transmit_time; + + if (unlikely(extra_len == 4)) + skb->no_fcs = 1; + + packet_parse_headers(skb, sock); + + if (vnet_hdr_sz) { + err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le()); + if (err) + goto out_free; + len += vnet_hdr_sz; + virtio_net_hdr_set_proto(skb, &vnet_hdr); + } + + err = packet_xmit(po, skb); + + if (unlikely(err != 0)) { + if (err > 0) + err = net_xmit_errno(err); + if (err) + goto out_unlock; + } + + dev_put(dev); + + return len; + +out_free: + kfree_skb(skb); +out_unlock: + dev_put(dev); +out: + return err; +} + +static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) +{ + struct sock *sk = sock->sk; + struct packet_sock *po = pkt_sk(sk); + + /* Reading tx_ring.pg_vec without holding pg_vec_lock is racy. + * tpacket_snd() will redo the check safely. + */ + if (data_race(po->tx_ring.pg_vec)) + return tpacket_snd(po, msg); + + return packet_snd(sock, msg, len); +} + +/* + * Close a PACKET socket. This is fairly simple. We immediately go + * to 'closed' state and remove our protocol entry in the device list. + */ + +static int packet_release(struct socket *sock) +{ + struct sock *sk = sock->sk; + struct packet_sock *po; + struct packet_fanout *f; + struct net *net; + union tpacket_req_u req_u; + + if (!sk) + return 0; + + net = sock_net(sk); + po = pkt_sk(sk); + + mutex_lock(&net->packet.sklist_lock); + sk_del_node_init_rcu(sk); + mutex_unlock(&net->packet.sklist_lock); + + sock_prot_inuse_add(net, sk->sk_prot, -1); + + spin_lock(&po->bind_lock); + unregister_prot_hook(sk, false); + packet_cached_dev_reset(po); + + if (po->prot_hook.dev) { + netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker); + po->prot_hook.dev = NULL; + } + spin_unlock(&po->bind_lock); + + packet_flush_mclist(sk); + + lock_sock(sk); + if (po->rx_ring.pg_vec) { + memset(&req_u, 0, sizeof(req_u)); + packet_set_ring(sk, &req_u, 1, 0); + } + + if (po->tx_ring.pg_vec) { + memset(&req_u, 0, sizeof(req_u)); + packet_set_ring(sk, &req_u, 1, 1); + } + release_sock(sk); + + f = fanout_release(sk); + + synchronize_net(); + + kfree(po->rollover); + if (f) { + fanout_release_data(f); + kvfree(f); + } + /* + * Now the socket is dead. No more input will appear. + */ + sock_orphan(sk); + sock->sk = NULL; + + /* Purge queues */ + + skb_queue_purge(&sk->sk_receive_queue); + packet_free_pending(po); + + sock_put(sk); + return 0; +} + +/* + * Attach a packet hook. + */ + +static int packet_do_bind(struct sock *sk, const char *name, int ifindex, + __be16 proto) +{ + struct packet_sock *po = pkt_sk(sk); + struct net_device *dev = NULL; + bool unlisted = false; + bool need_rehook; + int ret = 0; + + lock_sock(sk); + spin_lock(&po->bind_lock); + if (!proto) + proto = po->num; + + rcu_read_lock(); + + if (po->fanout) { + ret = -EINVAL; + goto out_unlock; + } + + if (name) { + dev = dev_get_by_name_rcu(sock_net(sk), name); + if (!dev) { + ret = -ENODEV; + goto out_unlock; + } + } else if (ifindex) { + dev = dev_get_by_index_rcu(sock_net(sk), ifindex); + if (!dev) { + ret = -ENODEV; + goto out_unlock; + } + } + + need_rehook = po->prot_hook.type != proto || po->prot_hook.dev != dev; + + if (need_rehook) { + dev_hold(dev); + if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { + rcu_read_unlock(); + /* prevents packet_notifier() from calling + * register_prot_hook() + */ + WRITE_ONCE(po->num, 0); + __unregister_prot_hook(sk, true); + rcu_read_lock(); + if (dev) + unlisted = !dev_get_by_index_rcu(sock_net(sk), + dev->ifindex); + } + + BUG_ON(packet_sock_flag(po, PACKET_SOCK_RUNNING)); + WRITE_ONCE(po->num, proto); + po->prot_hook.type = proto; + + netdev_put(po->prot_hook.dev, &po->prot_hook.dev_tracker); + + if (unlikely(unlisted)) { + po->prot_hook.dev = NULL; + WRITE_ONCE(po->ifindex, -1); + packet_cached_dev_reset(po); + } else { + netdev_hold(dev, &po->prot_hook.dev_tracker, + GFP_ATOMIC); + po->prot_hook.dev = dev; + WRITE_ONCE(po->ifindex, dev ? dev->ifindex : 0); + packet_cached_dev_assign(po, dev); + } + dev_put(dev); + } + + if (proto == 0 || !need_rehook) + goto out_unlock; + + if (!unlisted && (!dev || (dev->flags & IFF_UP))) { + register_prot_hook(sk); + } else { + sk->sk_err = ENETDOWN; + if (!sock_flag(sk, SOCK_DEAD)) + sk_error_report(sk); + } + +out_unlock: + rcu_read_unlock(); + spin_unlock(&po->bind_lock); + release_sock(sk); + return ret; +} + +/* + * Bind a packet socket to a device + */ + +static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr, + int addr_len) +{ + struct sock *sk = sock->sk; + char name[sizeof(uaddr->sa_data_min) + 1]; + + /* + * Check legality + */ + + if (addr_len != sizeof(struct sockaddr)) + return -EINVAL; + /* uaddr->sa_data comes from the userspace, it's not guaranteed to be + * zero-terminated. + */ + memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data_min)); + name[sizeof(uaddr->sa_data_min)] = 0; + + return packet_do_bind(sk, name, 0, 0); +} + +static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) +{ + struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr; + struct sock *sk = sock->sk; + + /* + * Check legality + */ + + if (addr_len < sizeof(struct sockaddr_ll)) + return -EINVAL; + if (sll->sll_family != AF_PACKET) + return -EINVAL; + + return packet_do_bind(sk, NULL, sll->sll_ifindex, sll->sll_protocol); +} + +static struct proto packet_proto = { + .name = "PACKET", + .owner = THIS_MODULE, + .obj_size = sizeof(struct packet_sock), +}; + +/* + * Create a packet of type SOCK_PACKET. + */ + +static int packet_create(struct net *net, struct socket *sock, int protocol, + int kern) +{ + struct sock *sk; + struct packet_sock *po; + __be16 proto = (__force __be16)protocol; /* weird, but documented */ + int err; + + if (!ns_capable(net->user_ns, CAP_NET_RAW)) + return -EPERM; + if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW && + sock->type != SOCK_PACKET) + return -ESOCKTNOSUPPORT; + + sock->state = SS_UNCONNECTED; + + err = -ENOBUFS; + sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern); + if (sk == NULL) + goto out; + + sock->ops = &packet_ops; + if (sock->type == SOCK_PACKET) + sock->ops = &packet_ops_spkt; + + sock_init_data(sock, sk); + + po = pkt_sk(sk); + init_completion(&po->skb_completion); + sk->sk_family = PF_PACKET; + po->num = proto; + + err = packet_alloc_pending(po); + if (err) + goto out2; + + packet_cached_dev_reset(po); + + sk->sk_destruct = packet_sock_destruct; + + /* + * Attach a protocol block + */ + + spin_lock_init(&po->bind_lock); + mutex_init(&po->pg_vec_lock); + po->rollover = NULL; + po->prot_hook.func = packet_rcv; + + if (sock->type == SOCK_PACKET) + po->prot_hook.func = packet_rcv_spkt; + + po->prot_hook.af_packet_priv = sk; + po->prot_hook.af_packet_net = sock_net(sk); + + if (proto) { + po->prot_hook.type = proto; + __register_prot_hook(sk); + } + + mutex_lock(&net->packet.sklist_lock); + sk_add_node_tail_rcu(sk, &net->packet.sklist); + mutex_unlock(&net->packet.sklist_lock); + + sock_prot_inuse_add(net, &packet_proto, 1); + + return 0; +out2: + sk_free(sk); +out: + return err; +} + +/* + * Pull a packet from our receive queue and hand it to the user. + * If necessary we block. + */ + +static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, + int flags) +{ + struct sock *sk = sock->sk; + struct sk_buff *skb; + int copied, err; + int vnet_hdr_len = READ_ONCE(pkt_sk(sk)->vnet_hdr_sz); + unsigned int origlen = 0; + + err = -EINVAL; + if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) + goto out; + +#if 0 + /* What error should we return now? EUNATTACH? */ + if (pkt_sk(sk)->ifindex < 0) + return -ENODEV; +#endif + + if (flags & MSG_ERRQUEUE) { + err = sock_recv_errqueue(sk, msg, len, + SOL_PACKET, PACKET_TX_TIMESTAMP); + goto out; + } + + /* + * Call the generic datagram receiver. This handles all sorts + * of horrible races and re-entrancy so we can forget about it + * in the protocol layers. + * + * Now it will return ENETDOWN, if device have just gone down, + * but then it will block. + */ + + skb = skb_recv_datagram(sk, flags, &err); + + /* + * An error occurred so return it. Because skb_recv_datagram() + * handles the blocking we don't see and worry about blocking + * retries. + */ + + if (skb == NULL) + goto out; + + packet_rcv_try_clear_pressure(pkt_sk(sk)); + + if (vnet_hdr_len) { + err = packet_rcv_vnet(msg, skb, &len, vnet_hdr_len); + if (err) + goto out_free; + } + + /* You lose any data beyond the buffer you gave. If it worries + * a user program they can ask the device for its MTU + * anyway. + */ + copied = skb->len; + if (copied > len) { + copied = len; + msg->msg_flags |= MSG_TRUNC; + } + + err = skb_copy_datagram_msg(skb, 0, msg, copied); + if (err) + goto out_free; + + if (sock->type != SOCK_PACKET) { + struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; + + /* Original length was stored in sockaddr_ll fields */ + origlen = PACKET_SKB_CB(skb)->sa.origlen; + sll->sll_family = AF_PACKET; + sll->sll_protocol = skb->protocol; + } + + sock_recv_cmsgs(msg, sk, skb); + + if (msg->msg_name) { + const size_t max_len = min(sizeof(skb->cb), + sizeof(struct sockaddr_storage)); + int copy_len; + + /* If the address length field is there to be filled + * in, we fill it in now. + */ + if (sock->type == SOCK_PACKET) { + __sockaddr_check_size(sizeof(struct sockaddr_pkt)); + msg->msg_namelen = sizeof(struct sockaddr_pkt); + copy_len = msg->msg_namelen; + } else { + struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll; + + msg->msg_namelen = sll->sll_halen + + offsetof(struct sockaddr_ll, sll_addr); + copy_len = msg->msg_namelen; + if (msg->msg_namelen < sizeof(struct sockaddr_ll)) { + memset(msg->msg_name + + offsetof(struct sockaddr_ll, sll_addr), + 0, sizeof(sll->sll_addr)); + msg->msg_namelen = sizeof(struct sockaddr_ll); + } + } + if (WARN_ON_ONCE(copy_len > max_len)) { + copy_len = max_len; + msg->msg_namelen = copy_len; + } + memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len); + } + + if (packet_sock_flag(pkt_sk(sk), PACKET_SOCK_AUXDATA)) { + struct tpacket_auxdata aux; + + aux.tp_status = TP_STATUS_USER; + if (skb->ip_summed == CHECKSUM_PARTIAL) + aux.tp_status |= TP_STATUS_CSUMNOTREADY; + else if (skb->pkt_type != PACKET_OUTGOING && + skb_csum_unnecessary(skb)) + aux.tp_status |= TP_STATUS_CSUM_VALID; + if (skb_is_gso(skb) && skb_is_gso_tcp(skb)) + aux.tp_status |= TP_STATUS_GSO_TCP; + + aux.tp_len = origlen; + aux.tp_snaplen = skb->len; + aux.tp_mac = 0; + aux.tp_net = skb_network_offset(skb); + if (skb_vlan_tag_present(skb)) { + aux.tp_vlan_tci = skb_vlan_tag_get(skb); + aux.tp_vlan_tpid = ntohs(skb->vlan_proto); + aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID; + } else { + aux.tp_vlan_tci = 0; + aux.tp_vlan_tpid = 0; + } + put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux); + } + + /* + * Free or return the buffer as appropriate. Again this + * hides all the races and re-entrancy issues from us. + */ + err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied); + +out_free: + skb_free_datagram(sk, skb); +out: + return err; +} + +static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr, + int peer) +{ + struct net_device *dev; + struct sock *sk = sock->sk; + + if (peer) + return -EOPNOTSUPP; + + uaddr->sa_family = AF_PACKET; + memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data_min)); + rcu_read_lock(); + dev = dev_get_by_index_rcu(sock_net(sk), READ_ONCE(pkt_sk(sk)->ifindex)); + if (dev) + strscpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data_min)); + rcu_read_unlock(); + + return sizeof(*uaddr); +} + +static int packet_getname(struct socket *sock, struct sockaddr *uaddr, + int peer) +{ + struct net_device *dev; + struct sock *sk = sock->sk; + struct packet_sock *po = pkt_sk(sk); + DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr); + int ifindex; + + if (peer) + return -EOPNOTSUPP; + + ifindex = READ_ONCE(po->ifindex); + sll->sll_family = AF_PACKET; + sll->sll_ifindex = ifindex; + sll->sll_protocol = READ_ONCE(po->num); + sll->sll_pkttype = 0; + rcu_read_lock(); + dev = dev_get_by_index_rcu(sock_net(sk), ifindex); + if (dev) { + sll->sll_hatype = dev->type; + sll->sll_halen = dev->addr_len; + + /* Let __fortify_memcpy_chk() know the actual buffer size. */ + memcpy(((struct sockaddr_storage *)sll)->__data + + offsetof(struct sockaddr_ll, sll_addr) - + offsetofend(struct sockaddr_ll, sll_family), + dev->dev_addr, dev->addr_len); + } else { + sll->sll_hatype = 0; /* Bad: we have no ARPHRD_UNSPEC */ + sll->sll_halen = 0; + } + rcu_read_unlock(); + + return offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen; +} + +static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i, + int what) +{ + switch (i->type) { + case PACKET_MR_MULTICAST: + if (i->alen != dev->addr_len) + return -EINVAL; + if (what > 0) + return dev_mc_add(dev, i->addr); + else + return dev_mc_del(dev, i->addr); + break; + case PACKET_MR_PROMISC: + return dev_set_promiscuity(dev, what); + case PACKET_MR_ALLMULTI: + return dev_set_allmulti(dev, what); + case PACKET_MR_UNICAST: + if (i->alen != dev->addr_len) + return -EINVAL; + if (what > 0) + return dev_uc_add(dev, i->addr); + else + return dev_uc_del(dev, i->addr); + break; + default: + break; + } + return 0; +} + +static void packet_dev_mclist_delete(struct net_device *dev, + struct packet_mclist **mlp) +{ + struct packet_mclist *ml; + + while ((ml = *mlp) != NULL) { + if (ml->ifindex == dev->ifindex) { + packet_dev_mc(dev, ml, -1); + *mlp = ml->next; + kfree(ml); + } else + mlp = &ml->next; + } +} + +static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) +{ + struct packet_sock *po = pkt_sk(sk); + struct packet_mclist *ml, *i; + struct net_device *dev; + int err; + + rtnl_lock(); + + err = -ENODEV; + dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex); + if (!dev) + goto done; + + err = -EINVAL; + if (mreq->mr_alen > dev->addr_len) + goto done; + + err = -ENOBUFS; + i = kmalloc(sizeof(*i), GFP_KERNEL); + if (i == NULL) + goto done; + + err = 0; + for (ml = po->mclist; ml; ml = ml->next) { + if (ml->ifindex == mreq->mr_ifindex && + ml->type == mreq->mr_type && + ml->alen == mreq->mr_alen && + memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { + ml->count++; + /* Free the new element ... */ + kfree(i); + goto done; + } + } + + i->type = mreq->mr_type; + i->ifindex = mreq->mr_ifindex; + i->alen = mreq->mr_alen; + memcpy(i->addr, mreq->mr_address, i->alen); + memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen); + i->count = 1; + i->next = po->mclist; + po->mclist = i; + err = packet_dev_mc(dev, i, 1); + if (err) { + po->mclist = i->next; + kfree(i); + } + +done: + rtnl_unlock(); + return err; +} + +static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq) +{ + struct packet_mclist *ml, **mlp; + + rtnl_lock(); + + for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) { + if (ml->ifindex == mreq->mr_ifindex && + ml->type == mreq->mr_type && + ml->alen == mreq->mr_alen && + memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) { + if (--ml->count == 0) { + struct net_device *dev; + *mlp = ml->next; + dev = __dev_get_by_index(sock_net(sk), ml->ifindex); + if (dev) + packet_dev_mc(dev, ml, -1); + kfree(ml); + } + break; + } + } + rtnl_unlock(); + return 0; +} + +static void packet_flush_mclist(struct sock *sk) +{ + struct packet_sock *po = pkt_sk(sk); + struct packet_mclist *ml; + + if (!po->mclist) + return; + + rtnl_lock(); + while ((ml = po->mclist) != NULL) { + struct net_device *dev; + + po->mclist = ml->next; + dev = __dev_get_by_index(sock_net(sk), ml->ifindex); + if (dev != NULL) + packet_dev_mc(dev, ml, -1); + kfree(ml); + } + rtnl_unlock(); +} + +static int +packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval, + unsigned int optlen) +{ + struct sock *sk = sock->sk; + struct packet_sock *po = pkt_sk(sk); + int ret; + + if (level != SOL_PACKET) + return -ENOPROTOOPT; + + switch (optname) { + case PACKET_ADD_MEMBERSHIP: + case PACKET_DROP_MEMBERSHIP: + { + struct packet_mreq_max mreq; + int len = optlen; + memset(&mreq, 0, sizeof(mreq)); + if (len < sizeof(struct packet_mreq)) + return -EINVAL; + if (len > sizeof(mreq)) + len = sizeof(mreq); + if (copy_from_sockptr(&mreq, optval, len)) + return -EFAULT; + if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address))) + return -EINVAL; + if (optname == PACKET_ADD_MEMBERSHIP) + ret = packet_mc_add(sk, &mreq); + else + ret = packet_mc_drop(sk, &mreq); + return ret; + } + + case PACKET_RX_RING: + case PACKET_TX_RING: + { + union tpacket_req_u req_u; + int len; + + lock_sock(sk); + switch (po->tp_version) { + case TPACKET_V1: + case TPACKET_V2: + len = sizeof(req_u.req); + break; + case TPACKET_V3: + default: + len = sizeof(req_u.req3); + break; + } + if (optlen < len) { + ret = -EINVAL; + } else { + if (copy_from_sockptr(&req_u.req, optval, len)) + ret = -EFAULT; + else + ret = packet_set_ring(sk, &req_u, 0, + optname == PACKET_TX_RING); + } + release_sock(sk); + return ret; + } + case PACKET_COPY_THRESH: + { + int val; + + if (optlen != sizeof(val)) + return -EINVAL; + if (copy_from_sockptr(&val, optval, sizeof(val))) + return -EFAULT; + + pkt_sk(sk)->copy_thresh = val; + return 0; + } + case PACKET_VERSION: + { + int val; + + if (optlen != sizeof(val)) + return -EINVAL; + if (copy_from_sockptr(&val, optval, sizeof(val))) + return -EFAULT; + switch (val) { + case TPACKET_V1: + case TPACKET_V2: + case TPACKET_V3: + break; + default: + return -EINVAL; + } + lock_sock(sk); + if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { + ret = -EBUSY; + } else { + po->tp_version = val; + ret = 0; + } + release_sock(sk); + return ret; + } + case PACKET_RESERVE: + { + unsigned int val; + + if (optlen != sizeof(val)) + return -EINVAL; + if (copy_from_sockptr(&val, optval, sizeof(val))) + return -EFAULT; + if (val > INT_MAX) + return -EINVAL; + lock_sock(sk); + if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { + ret = -EBUSY; + } else { + po->tp_reserve = val; + ret = 0; + } + release_sock(sk); + return ret; + } + case PACKET_LOSS: + { + unsigned int val; + + if (optlen != sizeof(val)) + return -EINVAL; + if (copy_from_sockptr(&val, optval, sizeof(val))) + return -EFAULT; + + lock_sock(sk); + if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { + ret = -EBUSY; + } else { + packet_sock_flag_set(po, PACKET_SOCK_TP_LOSS, val); + ret = 0; + } + release_sock(sk); + return ret; + } + case PACKET_AUXDATA: + { + int val; + + if (optlen < sizeof(val)) + return -EINVAL; + if (copy_from_sockptr(&val, optval, sizeof(val))) + return -EFAULT; + + packet_sock_flag_set(po, PACKET_SOCK_AUXDATA, val); + return 0; + } + case PACKET_ORIGDEV: + { + int val; + + if (optlen < sizeof(val)) + return -EINVAL; + if (copy_from_sockptr(&val, optval, sizeof(val))) + return -EFAULT; + + packet_sock_flag_set(po, PACKET_SOCK_ORIGDEV, val); + return 0; + } + case PACKET_VNET_HDR: + case PACKET_VNET_HDR_SZ: + { + int val, hdr_len; + + if (sock->type != SOCK_RAW) + return -EINVAL; + if (optlen < sizeof(val)) + return -EINVAL; + if (copy_from_sockptr(&val, optval, sizeof(val))) + return -EFAULT; + + if (optname == PACKET_VNET_HDR_SZ) { + if (val && val != sizeof(struct virtio_net_hdr) && + val != sizeof(struct virtio_net_hdr_mrg_rxbuf)) + return -EINVAL; + hdr_len = val; + } else { + hdr_len = val ? sizeof(struct virtio_net_hdr) : 0; + } + lock_sock(sk); + if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) { + ret = -EBUSY; + } else { + WRITE_ONCE(po->vnet_hdr_sz, hdr_len); + ret = 0; + } + release_sock(sk); + return ret; + } + case PACKET_TIMESTAMP: + { + int val; + + if (optlen != sizeof(val)) + return -EINVAL; + if (copy_from_sockptr(&val, optval, sizeof(val))) + return -EFAULT; + + WRITE_ONCE(po->tp_tstamp, val); + return 0; + } + case PACKET_FANOUT: + { + struct fanout_args args = { 0 }; + + if (optlen != sizeof(int) && optlen != sizeof(args)) + return -EINVAL; + if (copy_from_sockptr(&args, optval, optlen)) + return -EFAULT; + + return fanout_add(sk, &args); + } + case PACKET_FANOUT_DATA: + { + /* Paired with the WRITE_ONCE() in fanout_add() */ + if (!READ_ONCE(po->fanout)) + return -EINVAL; + + return fanout_set_data(po, optval, optlen); + } + case PACKET_IGNORE_OUTGOING: + { + int val; + + if (optlen != sizeof(val)) + return -EINVAL; + if (copy_from_sockptr(&val, optval, sizeof(val))) + return -EFAULT; + if (val < 0 || val > 1) + return -EINVAL; + + po->prot_hook.ignore_outgoing = !!val; + return 0; + } + case PACKET_TX_HAS_OFF: + { + unsigned int val; + + if (optlen != sizeof(val)) + return -EINVAL; + if (copy_from_sockptr(&val, optval, sizeof(val))) + return -EFAULT; + + lock_sock(sk); + if (!po->rx_ring.pg_vec && !po->tx_ring.pg_vec) + packet_sock_flag_set(po, PACKET_SOCK_TX_HAS_OFF, val); + + release_sock(sk); + return 0; + } + case PACKET_QDISC_BYPASS: + { + int val; + + if (optlen != sizeof(val)) + return -EINVAL; + if (copy_from_sockptr(&val, optval, sizeof(val))) + return -EFAULT; + + packet_sock_flag_set(po, PACKET_SOCK_QDISC_BYPASS, val); + return 0; + } + default: + return -ENOPROTOOPT; + } +} + +static int packet_getsockopt(struct socket *sock, int level, int optname, + char __user *optval, int __user *optlen) +{ + int len; + int val, lv = sizeof(val); + struct sock *sk = sock->sk; + struct packet_sock *po = pkt_sk(sk); + void *data = &val; + union tpacket_stats_u st; + struct tpacket_rollover_stats rstats; + int drops; + + if (level != SOL_PACKET) + return -ENOPROTOOPT; + + if (get_user(len, optlen)) + return -EFAULT; + + if (len < 0) + return -EINVAL; + + switch (optname) { + case PACKET_STATISTICS: + spin_lock_bh(&sk->sk_receive_queue.lock); + memcpy(&st, &po->stats, sizeof(st)); + memset(&po->stats, 0, sizeof(po->stats)); + spin_unlock_bh(&sk->sk_receive_queue.lock); + drops = atomic_xchg(&po->tp_drops, 0); + + if (po->tp_version == TPACKET_V3) { + lv = sizeof(struct tpacket_stats_v3); + st.stats3.tp_drops = drops; + st.stats3.tp_packets += drops; + data = &st.stats3; + } else { + lv = sizeof(struct tpacket_stats); + st.stats1.tp_drops = drops; + st.stats1.tp_packets += drops; + data = &st.stats1; + } + + break; + case PACKET_AUXDATA: + val = packet_sock_flag(po, PACKET_SOCK_AUXDATA); + break; + case PACKET_ORIGDEV: + val = packet_sock_flag(po, PACKET_SOCK_ORIGDEV); + break; + case PACKET_VNET_HDR: + val = !!READ_ONCE(po->vnet_hdr_sz); + break; + case PACKET_VNET_HDR_SZ: + val = READ_ONCE(po->vnet_hdr_sz); + break; + case PACKET_VERSION: + val = po->tp_version; + break; + case PACKET_HDRLEN: + if (len > sizeof(int)) + len = sizeof(int); + if (len < sizeof(int)) + return -EINVAL; + if (copy_from_user(&val, optval, len)) + return -EFAULT; + switch (val) { + case TPACKET_V1: + val = sizeof(struct tpacket_hdr); + break; + case TPACKET_V2: + val = sizeof(struct tpacket2_hdr); + break; + case TPACKET_V3: + val = sizeof(struct tpacket3_hdr); + break; + default: + return -EINVAL; + } + break; + case PACKET_RESERVE: + val = po->tp_reserve; + break; + case PACKET_LOSS: + val = packet_sock_flag(po, PACKET_SOCK_TP_LOSS); + break; + case PACKET_TIMESTAMP: + val = READ_ONCE(po->tp_tstamp); + break; + case PACKET_FANOUT: + val = (po->fanout ? + ((u32)po->fanout->id | + ((u32)po->fanout->type << 16) | + ((u32)po->fanout->flags << 24)) : + 0); + break; + case PACKET_IGNORE_OUTGOING: + val = po->prot_hook.ignore_outgoing; + break; + case PACKET_ROLLOVER_STATS: + if (!po->rollover) + return -EINVAL; + rstats.tp_all = atomic_long_read(&po->rollover->num); + rstats.tp_huge = atomic_long_read(&po->rollover->num_huge); + rstats.tp_failed = atomic_long_read(&po->rollover->num_failed); + data = &rstats; + lv = sizeof(rstats); + break; + case PACKET_TX_HAS_OFF: + val = packet_sock_flag(po, PACKET_SOCK_TX_HAS_OFF); + break; + case PACKET_QDISC_BYPASS: + val = packet_sock_flag(po, PACKET_SOCK_QDISC_BYPASS); + break; + default: + return -ENOPROTOOPT; + } + + if (len > lv) + len = lv; + if (put_user(len, optlen)) + return -EFAULT; + if (copy_to_user(optval, data, len)) + return -EFAULT; + return 0; +} + +static int packet_notifier(struct notifier_block *this, + unsigned long msg, void *ptr) +{ + struct sock *sk; + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct net *net = dev_net(dev); + + rcu_read_lock(); + sk_for_each_rcu(sk, &net->packet.sklist) { + struct packet_sock *po = pkt_sk(sk); + + switch (msg) { + case NETDEV_UNREGISTER: + if (po->mclist) + packet_dev_mclist_delete(dev, &po->mclist); + fallthrough; + + case NETDEV_DOWN: + if (dev->ifindex == po->ifindex) { + spin_lock(&po->bind_lock); + if (packet_sock_flag(po, PACKET_SOCK_RUNNING)) { + __unregister_prot_hook(sk, false); + sk->sk_err = ENETDOWN; + if (!sock_flag(sk, SOCK_DEAD)) + sk_error_report(sk); + } + if (msg == NETDEV_UNREGISTER) { + packet_cached_dev_reset(po); + WRITE_ONCE(po->ifindex, -1); + netdev_put(po->prot_hook.dev, + &po->prot_hook.dev_tracker); + po->prot_hook.dev = NULL; + } + spin_unlock(&po->bind_lock); + } + break; + case NETDEV_UP: + if (dev->ifindex == po->ifindex) { + spin_lock(&po->bind_lock); + if (po->num) + register_prot_hook(sk); + spin_unlock(&po->bind_lock); + } + break; + } + } + rcu_read_unlock(); + return NOTIFY_DONE; +} + + +static int packet_ioctl(struct socket *sock, unsigned int cmd, + unsigned long arg) +{ + struct sock *sk = sock->sk; + + switch (cmd) { + case SIOCOUTQ: + { + int amount = sk_wmem_alloc_get(sk); + + return put_user(amount, (int __user *)arg); + } + case SIOCINQ: + { + struct sk_buff *skb; + int amount = 0; + + spin_lock_bh(&sk->sk_receive_queue.lock); + skb = skb_peek(&sk->sk_receive_queue); + if (skb) + amount = skb->len; + spin_unlock_bh(&sk->sk_receive_queue.lock); + return put_user(amount, (int __user *)arg); + } +#ifdef CONFIG_INET + case SIOCADDRT: + case SIOCDELRT: + case SIOCDARP: + case SIOCGARP: + case SIOCSARP: + case SIOCGIFADDR: + case SIOCSIFADDR: + case SIOCGIFBRDADDR: + case SIOCSIFBRDADDR: + case SIOCGIFNETMASK: + case SIOCSIFNETMASK: + case SIOCGIFDSTADDR: + case SIOCSIFDSTADDR: + case SIOCSIFFLAGS: + return inet_dgram_ops.ioctl(sock, cmd, arg); +#endif + + default: + return -ENOIOCTLCMD; + } + return 0; +} + +static __poll_t packet_poll(struct file *file, struct socket *sock, + poll_table *wait) +{ + struct sock *sk = sock->sk; + struct packet_sock *po = pkt_sk(sk); + __poll_t mask = datagram_poll(file, sock, wait); + + spin_lock_bh(&sk->sk_receive_queue.lock); + if (po->rx_ring.pg_vec) { + if (!packet_previous_rx_frame(po, &po->rx_ring, + TP_STATUS_KERNEL)) + mask |= EPOLLIN | EPOLLRDNORM; + } + packet_rcv_try_clear_pressure(po); + spin_unlock_bh(&sk->sk_receive_queue.lock); + spin_lock_bh(&sk->sk_write_queue.lock); + if (po->tx_ring.pg_vec) { + if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE)) + mask |= EPOLLOUT | EPOLLWRNORM; + } + spin_unlock_bh(&sk->sk_write_queue.lock); + return mask; +} + + +/* Dirty? Well, I still did not learn better way to account + * for user mmaps. + */ + +static void packet_mm_open(struct vm_area_struct *vma) +{ + struct file *file = vma->vm_file; + struct socket *sock = file->private_data; + struct sock *sk = sock->sk; + + if (sk) + atomic_long_inc(&pkt_sk(sk)->mapped); +} + +static void packet_mm_close(struct vm_area_struct *vma) +{ + struct file *file = vma->vm_file; + struct socket *sock = file->private_data; + struct sock *sk = sock->sk; + + if (sk) + atomic_long_dec(&pkt_sk(sk)->mapped); +} + +static const struct vm_operations_struct packet_mmap_ops = { + .open = packet_mm_open, + .close = packet_mm_close, +}; + +static void free_pg_vec(struct pgv *pg_vec, unsigned int order, + unsigned int len) +{ + int i; + + for (i = 0; i < len; i++) { + if (likely(pg_vec[i].buffer)) { + if (is_vmalloc_addr(pg_vec[i].buffer)) + vfree(pg_vec[i].buffer); + else + free_pages((unsigned long)pg_vec[i].buffer, + order); + pg_vec[i].buffer = NULL; + } + } + kfree(pg_vec); +} + +static char *alloc_one_pg_vec_page(unsigned long order) +{ + char *buffer; + gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | + __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY; + + buffer = (char *) __get_free_pages(gfp_flags, order); + if (buffer) + return buffer; + + /* __get_free_pages failed, fall back to vmalloc */ + buffer = vzalloc(array_size((1 << order), PAGE_SIZE)); + if (buffer) + return buffer; + + /* vmalloc failed, lets dig into swap here */ + gfp_flags &= ~__GFP_NORETRY; + buffer = (char *) __get_free_pages(gfp_flags, order); + if (buffer) + return buffer; + + /* complete and utter failure */ + return NULL; +} + +static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order) +{ + unsigned int block_nr = req->tp_block_nr; + struct pgv *pg_vec; + int i; + + pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL | __GFP_NOWARN); + if (unlikely(!pg_vec)) + goto out; + + for (i = 0; i < block_nr; i++) { + pg_vec[i].buffer = alloc_one_pg_vec_page(order); + if (unlikely(!pg_vec[i].buffer)) + goto out_free_pgvec; + } + +out: + return pg_vec; + +out_free_pgvec: + free_pg_vec(pg_vec, order, block_nr); + pg_vec = NULL; + goto out; +} + +static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u, + int closing, int tx_ring) +{ + struct pgv *pg_vec = NULL; + struct packet_sock *po = pkt_sk(sk); + unsigned long *rx_owner_map = NULL; + int was_running, order = 0; + struct packet_ring_buffer *rb; + struct sk_buff_head *rb_queue; + __be16 num; + int err; + /* Added to avoid minimal code churn */ + struct tpacket_req *req = &req_u->req; + + rb = tx_ring ? &po->tx_ring : &po->rx_ring; + rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; + + err = -EBUSY; + if (!closing) { + if (atomic_long_read(&po->mapped)) + goto out; + if (packet_read_pending(rb)) + goto out; + } + + if (req->tp_block_nr) { + unsigned int min_frame_size; + + /* Sanity tests and some calculations */ + err = -EBUSY; + if (unlikely(rb->pg_vec)) + goto out; + + switch (po->tp_version) { + case TPACKET_V1: + po->tp_hdrlen = TPACKET_HDRLEN; + break; + case TPACKET_V2: + po->tp_hdrlen = TPACKET2_HDRLEN; + break; + case TPACKET_V3: + po->tp_hdrlen = TPACKET3_HDRLEN; + break; + } + + err = -EINVAL; + if (unlikely((int)req->tp_block_size <= 0)) + goto out; + if (unlikely(!PAGE_ALIGNED(req->tp_block_size))) + goto out; + min_frame_size = po->tp_hdrlen + po->tp_reserve; + if (po->tp_version >= TPACKET_V3 && + req->tp_block_size < + BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv) + min_frame_size) + goto out; + if (unlikely(req->tp_frame_size < min_frame_size)) + goto out; + if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1))) + goto out; + + rb->frames_per_block = req->tp_block_size / req->tp_frame_size; + if (unlikely(rb->frames_per_block == 0)) + goto out; + if (unlikely(rb->frames_per_block > UINT_MAX / req->tp_block_nr)) + goto out; + if (unlikely((rb->frames_per_block * req->tp_block_nr) != + req->tp_frame_nr)) + goto out; + + err = -ENOMEM; + order = get_order(req->tp_block_size); + pg_vec = alloc_pg_vec(req, order); + if (unlikely(!pg_vec)) + goto out; + switch (po->tp_version) { + case TPACKET_V3: + /* Block transmit is not supported yet */ + if (!tx_ring) { + init_prb_bdqc(po, rb, pg_vec, req_u); + } else { + struct tpacket_req3 *req3 = &req_u->req3; + + if (req3->tp_retire_blk_tov || + req3->tp_sizeof_priv || + req3->tp_feature_req_word) { + err = -EINVAL; + goto out_free_pg_vec; + } + } + break; + default: + if (!tx_ring) { + rx_owner_map = bitmap_alloc(req->tp_frame_nr, + GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO); + if (!rx_owner_map) + goto out_free_pg_vec; + } + break; + } + } + /* Done */ + else { + err = -EINVAL; + if (unlikely(req->tp_frame_nr)) + goto out; + } + + + /* Detach socket from network */ + spin_lock(&po->bind_lock); + was_running = packet_sock_flag(po, PACKET_SOCK_RUNNING); + num = po->num; + if (was_running) { + WRITE_ONCE(po->num, 0); + __unregister_prot_hook(sk, false); + } + spin_unlock(&po->bind_lock); + + synchronize_net(); + + err = -EBUSY; + mutex_lock(&po->pg_vec_lock); + if (closing || atomic_long_read(&po->mapped) == 0) { + err = 0; + spin_lock_bh(&rb_queue->lock); + swap(rb->pg_vec, pg_vec); + if (po->tp_version <= TPACKET_V2) + swap(rb->rx_owner_map, rx_owner_map); + rb->frame_max = (req->tp_frame_nr - 1); + rb->head = 0; + rb->frame_size = req->tp_frame_size; + spin_unlock_bh(&rb_queue->lock); + + swap(rb->pg_vec_order, order); + swap(rb->pg_vec_len, req->tp_block_nr); + + rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE; + po->prot_hook.func = (po->rx_ring.pg_vec) ? + tpacket_rcv : packet_rcv; + skb_queue_purge(rb_queue); + if (atomic_long_read(&po->mapped)) + pr_err("packet_mmap: vma is busy: %ld\n", + atomic_long_read(&po->mapped)); + } + mutex_unlock(&po->pg_vec_lock); + + spin_lock(&po->bind_lock); + if (was_running) { + WRITE_ONCE(po->num, num); + register_prot_hook(sk); + } + spin_unlock(&po->bind_lock); + if (pg_vec && (po->tp_version > TPACKET_V2)) { + /* Because we don't support block-based V3 on tx-ring */ + if (!tx_ring) + prb_shutdown_retire_blk_timer(po, rb_queue); + } + +out_free_pg_vec: + if (pg_vec) { + bitmap_free(rx_owner_map); + free_pg_vec(pg_vec, order, req->tp_block_nr); + } +out: + return err; +} + +static int packet_mmap(struct file *file, struct socket *sock, + struct vm_area_struct *vma) +{ + struct sock *sk = sock->sk; + struct packet_sock *po = pkt_sk(sk); + unsigned long size, expected_size; + struct packet_ring_buffer *rb; + unsigned long start; + int err = -EINVAL; + int i; + + if (vma->vm_pgoff) + return -EINVAL; + + mutex_lock(&po->pg_vec_lock); + + expected_size = 0; + for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { + if (rb->pg_vec) { + expected_size += rb->pg_vec_len + * rb->pg_vec_pages + * PAGE_SIZE; + } + } + + if (expected_size == 0) + goto out; + + size = vma->vm_end - vma->vm_start; + if (size != expected_size) + goto out; + + start = vma->vm_start; + for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) { + if (rb->pg_vec == NULL) + continue; + + for (i = 0; i < rb->pg_vec_len; i++) { + struct page *page; + void *kaddr = rb->pg_vec[i].buffer; + int pg_num; + + for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) { + page = pgv_to_page(kaddr); + err = vm_insert_page(vma, start, page); + if (unlikely(err)) + goto out; + start += PAGE_SIZE; + kaddr += PAGE_SIZE; + } + } + } + + atomic_long_inc(&po->mapped); + vma->vm_ops = &packet_mmap_ops; + err = 0; + +out: + mutex_unlock(&po->pg_vec_lock); + return err; +} + +static const struct proto_ops packet_ops_spkt = { + .family = PF_PACKET, + .owner = THIS_MODULE, + .release = packet_release, + .bind = packet_bind_spkt, + .connect = sock_no_connect, + .socketpair = sock_no_socketpair, + .accept = sock_no_accept, + .getname = packet_getname_spkt, + .poll = datagram_poll, + .ioctl = packet_ioctl, + .gettstamp = sock_gettstamp, + .listen = sock_no_listen, + .shutdown = sock_no_shutdown, + .sendmsg = packet_sendmsg_spkt, + .recvmsg = packet_recvmsg, + .mmap = sock_no_mmap, +}; + +static const struct proto_ops packet_ops = { + .family = PF_PACKET, + .owner = THIS_MODULE, + .release = packet_release, + .bind = packet_bind, + .connect = sock_no_connect, + .socketpair = sock_no_socketpair, + .accept = sock_no_accept, + .getname = packet_getname, + .poll = packet_poll, + .ioctl = packet_ioctl, + .gettstamp = sock_gettstamp, + .listen = sock_no_listen, + .shutdown = sock_no_shutdown, + .setsockopt = packet_setsockopt, + .getsockopt = packet_getsockopt, + .sendmsg = packet_sendmsg, + .recvmsg = packet_recvmsg, + .mmap = packet_mmap, +}; + +static const struct net_proto_family packet_family_ops = { + .family = PF_PACKET, + .create = packet_create, + .owner = THIS_MODULE, +}; + +static struct notifier_block packet_netdev_notifier = { + .notifier_call = packet_notifier, +}; + +#ifdef CONFIG_PROC_FS + +static void *packet_seq_start(struct seq_file *seq, loff_t *pos) + __acquires(RCU) +{ + struct net *net = seq_file_net(seq); + + rcu_read_lock(); + return seq_hlist_start_head_rcu(&net->packet.sklist, *pos); +} + +static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + struct net *net = seq_file_net(seq); + return seq_hlist_next_rcu(v, &net->packet.sklist, pos); +} + +static void packet_seq_stop(struct seq_file *seq, void *v) + __releases(RCU) +{ + rcu_read_unlock(); +} + +static int packet_seq_show(struct seq_file *seq, void *v) +{ + if (v == SEQ_START_TOKEN) + seq_printf(seq, + "%*sRefCnt Type Proto Iface R Rmem User Inode\n", + IS_ENABLED(CONFIG_64BIT) ? -17 : -9, "sk"); + else { + struct sock *s = sk_entry(v); + const struct packet_sock *po = pkt_sk(s); + + seq_printf(seq, + "%pK %-6d %-4d %04x %-5d %1d %-6u %-6u %-6lu\n", + s, + refcount_read(&s->sk_refcnt), + s->sk_type, + ntohs(READ_ONCE(po->num)), + READ_ONCE(po->ifindex), + packet_sock_flag(po, PACKET_SOCK_RUNNING), + atomic_read(&s->sk_rmem_alloc), + from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)), + sock_i_ino(s)); + } + + return 0; +} + +static const struct seq_operations packet_seq_ops = { + .start = packet_seq_start, + .next = packet_seq_next, + .stop = packet_seq_stop, + .show = packet_seq_show, +}; +#endif + +static int __net_init packet_net_init(struct net *net) +{ + mutex_init(&net->packet.sklist_lock); + INIT_HLIST_HEAD(&net->packet.sklist); + +#ifdef CONFIG_PROC_FS + if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops, + sizeof(struct seq_net_private))) + return -ENOMEM; +#endif /* CONFIG_PROC_FS */ + + return 0; +} + +static void __net_exit packet_net_exit(struct net *net) +{ + remove_proc_entry("packet", net->proc_net); + WARN_ON_ONCE(!hlist_empty(&net->packet.sklist)); +} + +static struct pernet_operations packet_net_ops = { + .init = packet_net_init, + .exit = packet_net_exit, +}; + + +static void __exit packet_exit(void) +{ + sock_unregister(PF_PACKET); + proto_unregister(&packet_proto); + unregister_netdevice_notifier(&packet_netdev_notifier); + unregister_pernet_subsys(&packet_net_ops); +} + +static int __init packet_init(void) +{ + int rc; + + rc = register_pernet_subsys(&packet_net_ops); + if (rc) + goto out; + rc = register_netdevice_notifier(&packet_netdev_notifier); + if (rc) + goto out_pernet; + rc = proto_register(&packet_proto, 0); + if (rc) + goto out_notifier; + rc = sock_register(&packet_family_ops); + if (rc) + goto out_proto; + + return 0; + +out_proto: + proto_unregister(&packet_proto); +out_notifier: + unregister_netdevice_notifier(&packet_netdev_notifier); +out_pernet: + unregister_pernet_subsys(&packet_net_ops); +out: + return rc; +} + +module_init(packet_init); +module_exit(packet_exit); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_NETPROTO(PF_PACKET); |