diff options
Diffstat (limited to 'kernel/bpf/sockmap.c')
| -rw-r--r-- | kernel/bpf/sockmap.c | 2631 |
1 files changed, 2631 insertions, 0 deletions
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c new file mode 100644 index 000000000..0a0f2ec75 --- /dev/null +++ b/kernel/bpf/sockmap.c @@ -0,0 +1,2631 @@ +/* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ + +/* A BPF sock_map is used to store sock objects. This is primarly used + * for doing socket redirect with BPF helper routines. + * + * A sock map may have BPF programs attached to it, currently a program + * used to parse packets and a program to provide a verdict and redirect + * decision on the packet are supported. Any programs attached to a sock + * map are inherited by sock objects when they are added to the map. If + * no BPF programs are attached the sock object may only be used for sock + * redirect. + * + * A sock object may be in multiple maps, but can only inherit a single + * parse or verdict program. If adding a sock object to a map would result + * in having multiple parsing programs the update will return an EBUSY error. + * + * For reference this program is similar to devmap used in XDP context + * reviewing these together may be useful. For an example please review + * ./samples/bpf/sockmap/. + */ +#include <linux/bpf.h> +#include <net/sock.h> +#include <linux/filter.h> +#include <linux/errno.h> +#include <linux/file.h> +#include <linux/kernel.h> +#include <linux/net.h> +#include <linux/skbuff.h> +#include <linux/workqueue.h> +#include <linux/list.h> +#include <linux/mm.h> +#include <net/strparser.h> +#include <net/tcp.h> +#include <linux/ptr_ring.h> +#include <net/inet_common.h> +#include <linux/sched/signal.h> + +#define SOCK_CREATE_FLAG_MASK \ + (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY) + +struct bpf_sock_progs { + struct bpf_prog *bpf_tx_msg; + struct bpf_prog *bpf_parse; + struct bpf_prog *bpf_verdict; +}; + +struct bpf_stab { + struct bpf_map map; + struct sock **sock_map; + struct bpf_sock_progs progs; + raw_spinlock_t lock; +}; + +struct bucket { + struct hlist_head head; + raw_spinlock_t lock; +}; + +struct bpf_htab { + struct bpf_map map; + struct bucket *buckets; + atomic_t count; + u32 n_buckets; + u32 elem_size; + struct bpf_sock_progs progs; + struct rcu_head rcu; +}; + +struct htab_elem { + struct rcu_head rcu; + struct hlist_node hash_node; + u32 hash; + struct sock *sk; + char key[0]; +}; + +enum smap_psock_state { + SMAP_TX_RUNNING, +}; + +struct smap_psock_map_entry { + struct list_head list; + struct bpf_map *map; + struct sock **entry; + struct htab_elem __rcu *hash_link; +}; + +struct smap_psock { + struct rcu_head rcu; + refcount_t refcnt; + + /* datapath variables */ + struct sk_buff_head rxqueue; + bool strp_enabled; + + /* datapath error path cache across tx work invocations */ + int save_rem; + int save_off; + struct sk_buff *save_skb; + + /* datapath variables for tx_msg ULP */ + struct sock *sk_redir; + int apply_bytes; + int cork_bytes; + int sg_size; + int eval; + struct sk_msg_buff *cork; + struct list_head ingress; + + struct strparser strp; + struct bpf_prog *bpf_tx_msg; + struct bpf_prog *bpf_parse; + struct bpf_prog *bpf_verdict; + struct list_head maps; + spinlock_t maps_lock; + + /* Back reference used when sock callback trigger sockmap operations */ + struct sock *sock; + unsigned long state; + + struct work_struct tx_work; + struct work_struct gc_work; + + struct proto *sk_proto; + void (*save_unhash)(struct sock *sk); + void (*save_close)(struct sock *sk, long timeout); + void (*save_data_ready)(struct sock *sk); + void (*save_write_space)(struct sock *sk); +}; + +static void smap_release_sock(struct smap_psock *psock, struct sock *sock); +static int bpf_tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, + int nonblock, int flags, int *addr_len); +static int bpf_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size); +static int bpf_tcp_sendpage(struct sock *sk, struct page *page, + int offset, size_t size, int flags); +static void bpf_tcp_unhash(struct sock *sk); +static void bpf_tcp_close(struct sock *sk, long timeout); + +static inline struct smap_psock *smap_psock_sk(const struct sock *sk) +{ + return rcu_dereference_sk_user_data(sk); +} + +static bool bpf_tcp_stream_read(const struct sock *sk) +{ + struct smap_psock *psock; + bool empty = true; + + rcu_read_lock(); + psock = smap_psock_sk(sk); + if (unlikely(!psock)) + goto out; + empty = list_empty(&psock->ingress); +out: + rcu_read_unlock(); + return !empty; +} + +enum { + SOCKMAP_IPV4, + SOCKMAP_IPV6, + SOCKMAP_NUM_PROTS, +}; + +enum { + SOCKMAP_BASE, + SOCKMAP_TX, + SOCKMAP_NUM_CONFIGS, +}; + +static struct proto *saved_tcpv6_prot __read_mostly; +static DEFINE_SPINLOCK(tcpv6_prot_lock); +static struct proto bpf_tcp_prots[SOCKMAP_NUM_PROTS][SOCKMAP_NUM_CONFIGS]; +static void build_protos(struct proto prot[SOCKMAP_NUM_CONFIGS], + struct proto *base) +{ + prot[SOCKMAP_BASE] = *base; + prot[SOCKMAP_BASE].unhash = bpf_tcp_unhash; + prot[SOCKMAP_BASE].close = bpf_tcp_close; + prot[SOCKMAP_BASE].recvmsg = bpf_tcp_recvmsg; + prot[SOCKMAP_BASE].stream_memory_read = bpf_tcp_stream_read; + + prot[SOCKMAP_TX] = prot[SOCKMAP_BASE]; + prot[SOCKMAP_TX].sendmsg = bpf_tcp_sendmsg; + prot[SOCKMAP_TX].sendpage = bpf_tcp_sendpage; +} + +static void update_sk_prot(struct sock *sk, struct smap_psock *psock) +{ + int family = sk->sk_family == AF_INET6 ? SOCKMAP_IPV6 : SOCKMAP_IPV4; + int conf = psock->bpf_tx_msg ? SOCKMAP_TX : SOCKMAP_BASE; + + sk->sk_prot = &bpf_tcp_prots[family][conf]; +} + +static int bpf_tcp_init(struct sock *sk) +{ + struct smap_psock *psock; + + rcu_read_lock(); + psock = smap_psock_sk(sk); + if (unlikely(!psock)) { + rcu_read_unlock(); + return -EINVAL; + } + + if (unlikely(psock->sk_proto)) { + rcu_read_unlock(); + return -EBUSY; + } + + psock->save_unhash = sk->sk_prot->unhash; + psock->save_close = sk->sk_prot->close; + psock->sk_proto = sk->sk_prot; + + /* Build IPv6 sockmap whenever the address of tcpv6_prot changes */ + if (sk->sk_family == AF_INET6 && + unlikely(sk->sk_prot != smp_load_acquire(&saved_tcpv6_prot))) { + spin_lock_bh(&tcpv6_prot_lock); + if (likely(sk->sk_prot != saved_tcpv6_prot)) { + build_protos(bpf_tcp_prots[SOCKMAP_IPV6], sk->sk_prot); + smp_store_release(&saved_tcpv6_prot, sk->sk_prot); + } + spin_unlock_bh(&tcpv6_prot_lock); + } + update_sk_prot(sk, psock); + rcu_read_unlock(); + return 0; +} + +static void smap_release_sock(struct smap_psock *psock, struct sock *sock); +static int free_start_sg(struct sock *sk, struct sk_msg_buff *md, bool charge); + +static void bpf_tcp_release(struct sock *sk) +{ + struct smap_psock *psock; + + rcu_read_lock(); + psock = smap_psock_sk(sk); + if (unlikely(!psock)) + goto out; + + if (psock->cork) { + free_start_sg(psock->sock, psock->cork, true); + kfree(psock->cork); + psock->cork = NULL; + } + + if (psock->sk_proto) { + sk->sk_prot = psock->sk_proto; + psock->sk_proto = NULL; + } +out: + rcu_read_unlock(); +} + +static struct htab_elem *lookup_elem_raw(struct hlist_head *head, + u32 hash, void *key, u32 key_size) +{ + struct htab_elem *l; + + hlist_for_each_entry_rcu(l, head, hash_node) { + if (l->hash == hash && !memcmp(&l->key, key, key_size)) + return l; + } + + return NULL; +} + +static inline struct bucket *__select_bucket(struct bpf_htab *htab, u32 hash) +{ + return &htab->buckets[hash & (htab->n_buckets - 1)]; +} + +static inline struct hlist_head *select_bucket(struct bpf_htab *htab, u32 hash) +{ + return &__select_bucket(htab, hash)->head; +} + +static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l) +{ + atomic_dec(&htab->count); + kfree_rcu(l, rcu); +} + +static struct smap_psock_map_entry *psock_map_pop(struct sock *sk, + struct smap_psock *psock) +{ + struct smap_psock_map_entry *e; + + spin_lock_bh(&psock->maps_lock); + e = list_first_entry_or_null(&psock->maps, + struct smap_psock_map_entry, + list); + if (e) + list_del(&e->list); + spin_unlock_bh(&psock->maps_lock); + return e; +} + +static void bpf_tcp_remove(struct sock *sk, struct smap_psock *psock) +{ + struct smap_psock_map_entry *e; + struct sk_msg_buff *md, *mtmp; + struct sock *osk; + + if (psock->cork) { + free_start_sg(psock->sock, psock->cork, true); + kfree(psock->cork); + psock->cork = NULL; + } + + list_for_each_entry_safe(md, mtmp, &psock->ingress, list) { + list_del(&md->list); + free_start_sg(psock->sock, md, true); + kfree(md); + } + + e = psock_map_pop(sk, psock); + while (e) { + if (e->entry) { + struct bpf_stab *stab = container_of(e->map, struct bpf_stab, map); + + raw_spin_lock_bh(&stab->lock); + osk = *e->entry; + if (osk == sk) { + *e->entry = NULL; + smap_release_sock(psock, sk); + } + raw_spin_unlock_bh(&stab->lock); + } else { + struct htab_elem *link = rcu_dereference(e->hash_link); + struct bpf_htab *htab = container_of(e->map, struct bpf_htab, map); + struct hlist_head *head; + struct htab_elem *l; + struct bucket *b; + + b = __select_bucket(htab, link->hash); + head = &b->head; + raw_spin_lock_bh(&b->lock); + l = lookup_elem_raw(head, + link->hash, link->key, + htab->map.key_size); + /* If another thread deleted this object skip deletion. + * The refcnt on psock may or may not be zero. + */ + if (l && l == link) { + hlist_del_rcu(&link->hash_node); + smap_release_sock(psock, link->sk); + free_htab_elem(htab, link); + } + raw_spin_unlock_bh(&b->lock); + } + kfree(e); + e = psock_map_pop(sk, psock); + } +} + +static void bpf_tcp_unhash(struct sock *sk) +{ + void (*unhash_fun)(struct sock *sk); + struct smap_psock *psock; + + rcu_read_lock(); + psock = smap_psock_sk(sk); + if (unlikely(!psock)) { + rcu_read_unlock(); + if (sk->sk_prot->unhash) + sk->sk_prot->unhash(sk); + return; + } + unhash_fun = psock->save_unhash; + bpf_tcp_remove(sk, psock); + rcu_read_unlock(); + unhash_fun(sk); +} + +static void bpf_tcp_close(struct sock *sk, long timeout) +{ + void (*close_fun)(struct sock *sk, long timeout); + struct smap_psock *psock; + + lock_sock(sk); + rcu_read_lock(); + psock = smap_psock_sk(sk); + if (unlikely(!psock)) { + rcu_read_unlock(); + release_sock(sk); + return sk->sk_prot->close(sk, timeout); + } + close_fun = psock->save_close; + bpf_tcp_remove(sk, psock); + rcu_read_unlock(); + release_sock(sk); + close_fun(sk, timeout); +} + +enum __sk_action { + __SK_DROP = 0, + __SK_PASS, + __SK_REDIRECT, + __SK_NONE, +}; + +static struct tcp_ulp_ops bpf_tcp_ulp_ops __read_mostly = { + .name = "bpf_tcp", + .uid = TCP_ULP_BPF, + .user_visible = false, + .owner = NULL, + .init = bpf_tcp_init, + .release = bpf_tcp_release, +}; + +static int memcopy_from_iter(struct sock *sk, + struct sk_msg_buff *md, + struct iov_iter *from, int bytes) +{ + struct scatterlist *sg = md->sg_data; + int i = md->sg_curr, rc = -ENOSPC; + + do { + int copy; + char *to; + + if (md->sg_copybreak >= sg[i].length) { + md->sg_copybreak = 0; + + if (++i == MAX_SKB_FRAGS) + i = 0; + + if (i == md->sg_end) + break; + } + + copy = sg[i].length - md->sg_copybreak; + to = sg_virt(&sg[i]) + md->sg_copybreak; + md->sg_copybreak += copy; + + if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) + rc = copy_from_iter_nocache(to, copy, from); + else + rc = copy_from_iter(to, copy, from); + + if (rc != copy) { + rc = -EFAULT; + goto out; + } + + bytes -= copy; + if (!bytes) + break; + + md->sg_copybreak = 0; + if (++i == MAX_SKB_FRAGS) + i = 0; + } while (i != md->sg_end); +out: + md->sg_curr = i; + return rc; +} + +static int bpf_tcp_push(struct sock *sk, int apply_bytes, + struct sk_msg_buff *md, + int flags, bool uncharge) +{ + bool apply = apply_bytes; + struct scatterlist *sg; + int offset, ret = 0; + struct page *p; + size_t size; + + while (1) { + sg = md->sg_data + md->sg_start; + size = (apply && apply_bytes < sg->length) ? + apply_bytes : sg->length; + offset = sg->offset; + + tcp_rate_check_app_limited(sk); + p = sg_page(sg); +retry: + ret = do_tcp_sendpages(sk, p, offset, size, flags); + if (ret != size) { + if (ret > 0) { + if (apply) + apply_bytes -= ret; + + sg->offset += ret; + sg->length -= ret; + size -= ret; + offset += ret; + if (uncharge) + sk_mem_uncharge(sk, ret); + goto retry; + } + + return ret; + } + + if (apply) + apply_bytes -= ret; + sg->offset += ret; + sg->length -= ret; + if (uncharge) + sk_mem_uncharge(sk, ret); + + if (!sg->length) { + put_page(p); + md->sg_start++; + if (md->sg_start == MAX_SKB_FRAGS) + md->sg_start = 0; + sg_init_table(sg, 1); + + if (md->sg_start == md->sg_end) + break; + } + + if (apply && !apply_bytes) + break; + } + return 0; +} + +static inline void bpf_compute_data_pointers_sg(struct sk_msg_buff *md) +{ + struct scatterlist *sg = md->sg_data + md->sg_start; + + if (md->sg_copy[md->sg_start]) { + md->data = md->data_end = 0; + } else { + md->data = sg_virt(sg); + md->data_end = md->data + sg->length; + } +} + +static void return_mem_sg(struct sock *sk, int bytes, struct sk_msg_buff *md) +{ + struct scatterlist *sg = md->sg_data; + int i = md->sg_start; + + do { + int uncharge = (bytes < sg[i].length) ? bytes : sg[i].length; + + sk_mem_uncharge(sk, uncharge); + bytes -= uncharge; + if (!bytes) + break; + i++; + if (i == MAX_SKB_FRAGS) + i = 0; + } while (i != md->sg_end); +} + +static void free_bytes_sg(struct sock *sk, int bytes, + struct sk_msg_buff *md, bool charge) +{ + struct scatterlist *sg = md->sg_data; + int i = md->sg_start, free; + + while (bytes && sg[i].length) { + free = sg[i].length; + if (bytes < free) { + sg[i].length -= bytes; + sg[i].offset += bytes; + if (charge) + sk_mem_uncharge(sk, bytes); + break; + } + + if (charge) + sk_mem_uncharge(sk, sg[i].length); + put_page(sg_page(&sg[i])); + bytes -= sg[i].length; + sg[i].length = 0; + sg[i].page_link = 0; + sg[i].offset = 0; + i++; + + if (i == MAX_SKB_FRAGS) + i = 0; + } + md->sg_start = i; +} + +static int free_sg(struct sock *sk, int start, + struct sk_msg_buff *md, bool charge) +{ + struct scatterlist *sg = md->sg_data; + int i = start, free = 0; + + while (sg[i].length) { + free += sg[i].length; + if (charge) + sk_mem_uncharge(sk, sg[i].length); + if (!md->skb) + put_page(sg_page(&sg[i])); + sg[i].length = 0; + sg[i].page_link = 0; + sg[i].offset = 0; + i++; + + if (i == MAX_SKB_FRAGS) + i = 0; + } + if (md->skb) + consume_skb(md->skb); + + return free; +} + +static int free_start_sg(struct sock *sk, struct sk_msg_buff *md, bool charge) +{ + int free = free_sg(sk, md->sg_start, md, charge); + + md->sg_start = md->sg_end; + return free; +} + +static int free_curr_sg(struct sock *sk, struct sk_msg_buff *md) +{ + return free_sg(sk, md->sg_curr, md, true); +} + +static int bpf_map_msg_verdict(int _rc, struct sk_msg_buff *md) +{ + return ((_rc == SK_PASS) ? + (md->sk_redir ? __SK_REDIRECT : __SK_PASS) : + __SK_DROP); +} + +static unsigned int smap_do_tx_msg(struct sock *sk, + struct smap_psock *psock, + struct sk_msg_buff *md) +{ + struct bpf_prog *prog; + unsigned int rc, _rc; + + preempt_disable(); + rcu_read_lock(); + + /* If the policy was removed mid-send then default to 'accept' */ + prog = READ_ONCE(psock->bpf_tx_msg); + if (unlikely(!prog)) { + _rc = SK_PASS; + goto verdict; + } + + bpf_compute_data_pointers_sg(md); + md->sk = sk; + rc = (*prog->bpf_func)(md, prog->insnsi); + psock->apply_bytes = md->apply_bytes; + + /* Moving return codes from UAPI namespace into internal namespace */ + _rc = bpf_map_msg_verdict(rc, md); + + /* The psock has a refcount on the sock but not on the map and because + * we need to drop rcu read lock here its possible the map could be + * removed between here and when we need it to execute the sock + * redirect. So do the map lookup now for future use. + */ + if (_rc == __SK_REDIRECT) { + if (psock->sk_redir) + sock_put(psock->sk_redir); + psock->sk_redir = do_msg_redirect_map(md); + if (!psock->sk_redir) { + _rc = __SK_DROP; + goto verdict; + } + sock_hold(psock->sk_redir); + } +verdict: + rcu_read_unlock(); + preempt_enable(); + + return _rc; +} + +static int bpf_tcp_ingress(struct sock *sk, int apply_bytes, + struct smap_psock *psock, + struct sk_msg_buff *md, int flags) +{ + bool apply = apply_bytes; + size_t size, copied = 0; + struct sk_msg_buff *r; + int err = 0, i; + + r = kzalloc(sizeof(struct sk_msg_buff), __GFP_NOWARN | GFP_KERNEL); + if (unlikely(!r)) + return -ENOMEM; + + lock_sock(sk); + r->sg_start = md->sg_start; + i = md->sg_start; + + do { + size = (apply && apply_bytes < md->sg_data[i].length) ? + apply_bytes : md->sg_data[i].length; + + if (!sk_wmem_schedule(sk, size)) { + if (!copied) + err = -ENOMEM; + break; + } + + sk_mem_charge(sk, size); + r->sg_data[i] = md->sg_data[i]; + r->sg_data[i].length = size; + md->sg_data[i].length -= size; + md->sg_data[i].offset += size; + copied += size; + + if (md->sg_data[i].length) { + get_page(sg_page(&r->sg_data[i])); + r->sg_end = (i + 1) == MAX_SKB_FRAGS ? 0 : i + 1; + } else { + i++; + if (i == MAX_SKB_FRAGS) + i = 0; + r->sg_end = i; + } + + if (apply) { + apply_bytes -= size; + if (!apply_bytes) + break; + } + } while (i != md->sg_end); + + md->sg_start = i; + + if (!err) { + list_add_tail(&r->list, &psock->ingress); + sk->sk_data_ready(sk); + } else { + free_start_sg(sk, r, true); + kfree(r); + } + + release_sock(sk); + return err; +} + +static int bpf_tcp_sendmsg_do_redirect(struct sock *sk, int send, + struct sk_msg_buff *md, + int flags) +{ + bool ingress = !!(md->flags & BPF_F_INGRESS); + struct smap_psock *psock; + int err = 0; + + rcu_read_lock(); + psock = smap_psock_sk(sk); + if (unlikely(!psock)) + goto out_rcu; + + if (!refcount_inc_not_zero(&psock->refcnt)) + goto out_rcu; + + rcu_read_unlock(); + + if (ingress) { + err = bpf_tcp_ingress(sk, send, psock, md, flags); + } else { + lock_sock(sk); + err = bpf_tcp_push(sk, send, md, flags, false); + release_sock(sk); + } + smap_release_sock(psock, sk); + return err; +out_rcu: + rcu_read_unlock(); + return 0; +} + +static inline void bpf_md_init(struct smap_psock *psock) +{ + if (!psock->apply_bytes) { + psock->eval = __SK_NONE; + if (psock->sk_redir) { + sock_put(psock->sk_redir); + psock->sk_redir = NULL; + } + } +} + +static void apply_bytes_dec(struct smap_psock *psock, int i) +{ + if (psock->apply_bytes) { + if (psock->apply_bytes < i) + psock->apply_bytes = 0; + else + psock->apply_bytes -= i; + } +} + +static int bpf_exec_tx_verdict(struct smap_psock *psock, + struct sk_msg_buff *m, + struct sock *sk, + int *copied, int flags) +{ + bool cork = false, enospc = (m->sg_start == m->sg_end); + struct sock *redir; + int err = 0; + int send; + +more_data: + if (psock->eval == __SK_NONE) + psock->eval = smap_do_tx_msg(sk, psock, m); + + if (m->cork_bytes && + m->cork_bytes > psock->sg_size && !enospc) { + psock->cork_bytes = m->cork_bytes - psock->sg_size; + if (!psock->cork) { + psock->cork = kcalloc(1, + sizeof(struct sk_msg_buff), + GFP_ATOMIC | __GFP_NOWARN); + + if (!psock->cork) { + err = -ENOMEM; + goto out_err; + } + } + memcpy(psock->cork, m, sizeof(*m)); + goto out_err; + } + + send = psock->sg_size; + if (psock->apply_bytes && psock->apply_bytes < send) + send = psock->apply_bytes; + + switch (psock->eval) { + case __SK_PASS: + err = bpf_tcp_push(sk, send, m, flags, true); + if (unlikely(err)) { + *copied -= free_start_sg(sk, m, true); + break; + } + + apply_bytes_dec(psock, send); + psock->sg_size -= send; + break; + case __SK_REDIRECT: + redir = psock->sk_redir; + apply_bytes_dec(psock, send); + + if (psock->cork) { + cork = true; + psock->cork = NULL; + } + + return_mem_sg(sk, send, m); + release_sock(sk); + + err = bpf_tcp_sendmsg_do_redirect(redir, send, m, flags); + lock_sock(sk); + + if (unlikely(err < 0)) { + int free = free_start_sg(sk, m, false); + + psock->sg_size = 0; + if (!cork) + *copied -= free; + } else { + psock->sg_size -= send; + } + + if (cork) { + free_start_sg(sk, m, true); + psock->sg_size = 0; + kfree(m); + m = NULL; + err = 0; + } + break; + case __SK_DROP: + default: + free_bytes_sg(sk, send, m, true); + apply_bytes_dec(psock, send); + *copied -= send; + psock->sg_size -= send; + err = -EACCES; + break; + } + + if (likely(!err)) { + bpf_md_init(psock); + if (m && + m->sg_data[m->sg_start].page_link && + m->sg_data[m->sg_start].length) + goto more_data; + } + +out_err: + return err; +} + +static int bpf_wait_data(struct sock *sk, + struct smap_psock *psk, int flags, + long timeo, int *err) +{ + int rc; + + DEFINE_WAIT_FUNC(wait, woken_wake_function); + + add_wait_queue(sk_sleep(sk), &wait); + sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); + rc = sk_wait_event(sk, &timeo, + !list_empty(&psk->ingress) || + !skb_queue_empty(&sk->sk_receive_queue), + &wait); + sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); + remove_wait_queue(sk_sleep(sk), &wait); + + return rc; +} + +static int bpf_tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, + int nonblock, int flags, int *addr_len) +{ + struct iov_iter *iter = &msg->msg_iter; + struct smap_psock *psock; + int copied = 0; + + if (unlikely(flags & MSG_ERRQUEUE)) + return inet_recv_error(sk, msg, len, addr_len); + if (!skb_queue_empty(&sk->sk_receive_queue)) + return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len); + + rcu_read_lock(); + psock = smap_psock_sk(sk); + if (unlikely(!psock)) + goto out; + + if (unlikely(!refcount_inc_not_zero(&psock->refcnt))) + goto out; + rcu_read_unlock(); + + lock_sock(sk); +bytes_ready: + while (copied != len) { + struct scatterlist *sg; + struct sk_msg_buff *md; + int i; + + md = list_first_entry_or_null(&psock->ingress, + struct sk_msg_buff, list); + if (unlikely(!md)) + break; + i = md->sg_start; + do { + struct page *page; + int n, copy; + + sg = &md->sg_data[i]; + copy = sg->length; + page = sg_page(sg); + + if (copied + copy > len) + copy = len - copied; + + n = copy_page_to_iter(page, sg->offset, copy, iter); + if (n != copy) { + md->sg_start = i; + release_sock(sk); + smap_release_sock(psock, sk); + return -EFAULT; + } + + copied += copy; + sg->offset += copy; + sg->length -= copy; + sk_mem_uncharge(sk, copy); + + if (!sg->length) { + i++; + if (i == MAX_SKB_FRAGS) + i = 0; + if (!md->skb) + put_page(page); + } + if (copied == len) + break; + } while (i != md->sg_end); + md->sg_start = i; + + if (!sg->length && md->sg_start == md->sg_end) { + list_del(&md->list); + if (md->skb) + consume_skb(md->skb); + kfree(md); + } + } + + if (!copied) { + long timeo; + int data; + int err = 0; + + timeo = sock_rcvtimeo(sk, nonblock); + data = bpf_wait_data(sk, psock, flags, timeo, &err); + + if (data) { + if (!skb_queue_empty(&sk->sk_receive_queue)) { + release_sock(sk); + smap_release_sock(psock, sk); + copied = tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len); + return copied; + } + goto bytes_ready; + } + + if (err) + copied = err; + } + + release_sock(sk); + smap_release_sock(psock, sk); + return copied; +out: + rcu_read_unlock(); + return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len); +} + + +static int bpf_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) +{ + int flags = msg->msg_flags | MSG_NO_SHARED_FRAGS; + struct sk_msg_buff md = {0}; + unsigned int sg_copy = 0; + struct smap_psock *psock; + int copied = 0, err = 0; + struct scatterlist *sg; + long timeo; + + /* Its possible a sock event or user removed the psock _but_ the ops + * have not been reprogrammed yet so we get here. In this case fallback + * to tcp_sendmsg. Note this only works because we _only_ ever allow + * a single ULP there is no hierarchy here. + */ + rcu_read_lock(); + psock = smap_psock_sk(sk); + if (unlikely(!psock)) { + rcu_read_unlock(); + return tcp_sendmsg(sk, msg, size); + } + + /* Increment the psock refcnt to ensure its not released while sending a + * message. Required because sk lookup and bpf programs are used in + * separate rcu critical sections. Its OK if we lose the map entry + * but we can't lose the sock reference. + */ + if (!refcount_inc_not_zero(&psock->refcnt)) { + rcu_read_unlock(); + return tcp_sendmsg(sk, msg, size); + } + + sg = md.sg_data; + sg_init_marker(sg, MAX_SKB_FRAGS); + rcu_read_unlock(); + + lock_sock(sk); + timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); + + while (msg_data_left(msg)) { + struct sk_msg_buff *m = NULL; + bool enospc = false; + int copy; + + if (sk->sk_err) { + err = -sk->sk_err; + goto out_err; + } + + copy = msg_data_left(msg); + if (!sk_stream_memory_free(sk)) + goto wait_for_sndbuf; + + m = psock->cork_bytes ? psock->cork : &md; + m->sg_curr = m->sg_copybreak ? m->sg_curr : m->sg_end; + err = sk_alloc_sg(sk, copy, m->sg_data, + m->sg_start, &m->sg_end, &sg_copy, + m->sg_end - 1); + if (err) { + if (err != -ENOSPC) + goto wait_for_memory; + enospc = true; + copy = sg_copy; + } + + err = memcopy_from_iter(sk, m, &msg->msg_iter, copy); + if (err < 0) { + free_curr_sg(sk, m); + goto out_err; + } + + psock->sg_size += copy; + copied += copy; + sg_copy = 0; + + /* When bytes are being corked skip running BPF program and + * applying verdict unless there is no more buffer space. In + * the ENOSPC case simply run BPF prorgram with currently + * accumulated data. We don't have much choice at this point + * we could try extending the page frags or chaining complex + * frags but even in these cases _eventually_ we will hit an + * OOM scenario. More complex recovery schemes may be + * implemented in the future, but BPF programs must handle + * the case where apply_cork requests are not honored. The + * canonical method to verify this is to check data length. + */ + if (psock->cork_bytes) { + if (copy > psock->cork_bytes) + psock->cork_bytes = 0; + else + psock->cork_bytes -= copy; + + if (psock->cork_bytes && !enospc) + goto out_cork; + + /* All cork bytes accounted for re-run filter */ + psock->eval = __SK_NONE; + psock->cork_bytes = 0; + } + + err = bpf_exec_tx_verdict(psock, m, sk, &copied, flags); + if (unlikely(err < 0)) + goto out_err; + continue; +wait_for_sndbuf: + set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); +wait_for_memory: + err = sk_stream_wait_memory(sk, &timeo); + if (err) { + if (m && m != psock->cork) + free_start_sg(sk, m, true); + goto out_err; + } + } +out_err: + if (err < 0) + err = sk_stream_error(sk, msg->msg_flags, err); +out_cork: + release_sock(sk); + smap_release_sock(psock, sk); + return copied ? copied : err; +} + +static int bpf_tcp_sendpage(struct sock *sk, struct page *page, + int offset, size_t size, int flags) +{ + struct sk_msg_buff md = {0}, *m = NULL; + int err = 0, copied = 0; + struct smap_psock *psock; + struct scatterlist *sg; + bool enospc = false; + + rcu_read_lock(); + psock = smap_psock_sk(sk); + if (unlikely(!psock)) + goto accept; + + if (!refcount_inc_not_zero(&psock->refcnt)) + goto accept; + rcu_read_unlock(); + + lock_sock(sk); + + if (psock->cork_bytes) { + m = psock->cork; + sg = &m->sg_data[m->sg_end]; + } else { + m = &md; + sg = m->sg_data; + sg_init_marker(sg, MAX_SKB_FRAGS); + } + + /* Catch case where ring is full and sendpage is stalled. */ + if (unlikely(m->sg_end == m->sg_start && + m->sg_data[m->sg_end].length)) + goto out_err; + + psock->sg_size += size; + sg_set_page(sg, page, size, offset); + get_page(page); + m->sg_copy[m->sg_end] = true; + sk_mem_charge(sk, size); + m->sg_end++; + copied = size; + + if (m->sg_end == MAX_SKB_FRAGS) + m->sg_end = 0; + + if (m->sg_end == m->sg_start) + enospc = true; + + if (psock->cork_bytes) { + if (size > psock->cork_bytes) + psock->cork_bytes = 0; + else + psock->cork_bytes -= size; + + if (psock->cork_bytes && !enospc) + goto out_err; + + /* All cork bytes accounted for re-run filter */ + psock->eval = __SK_NONE; + psock->cork_bytes = 0; + } + + err = bpf_exec_tx_verdict(psock, m, sk, &copied, flags); +out_err: + release_sock(sk); + smap_release_sock(psock, sk); + return copied ? copied : err; +accept: + rcu_read_unlock(); + return tcp_sendpage(sk, page, offset, size, flags); +} + +static void bpf_tcp_msg_add(struct smap_psock *psock, + struct sock *sk, + struct bpf_prog *tx_msg) +{ + struct bpf_prog *orig_tx_msg; + + orig_tx_msg = xchg(&psock->bpf_tx_msg, tx_msg); + if (orig_tx_msg) + bpf_prog_put(orig_tx_msg); +} + +static int bpf_tcp_ulp_register(void) +{ + build_protos(bpf_tcp_prots[SOCKMAP_IPV4], &tcp_prot); + /* Once BPF TX ULP is registered it is never unregistered. It + * will be in the ULP list for the lifetime of the system. Doing + * duplicate registers is not a problem. + */ + return tcp_register_ulp(&bpf_tcp_ulp_ops); +} + +static int smap_verdict_func(struct smap_psock *psock, struct sk_buff *skb) +{ + struct bpf_prog *prog = READ_ONCE(psock->bpf_verdict); + int rc; + + if (unlikely(!prog)) + return __SK_DROP; + + skb_orphan(skb); + /* We need to ensure that BPF metadata for maps is also cleared + * when we orphan the skb so that we don't have the possibility + * to reference a stale map. + */ + TCP_SKB_CB(skb)->bpf.sk_redir = NULL; + skb->sk = psock->sock; + bpf_compute_data_end_sk_skb(skb); + preempt_disable(); + rc = (*prog->bpf_func)(skb, prog->insnsi); + preempt_enable(); + skb->sk = NULL; + + /* Moving return codes from UAPI namespace into internal namespace */ + return rc == SK_PASS ? + (TCP_SKB_CB(skb)->bpf.sk_redir ? __SK_REDIRECT : __SK_PASS) : + __SK_DROP; +} + +static int smap_do_ingress(struct smap_psock *psock, struct sk_buff *skb) +{ + struct sock *sk = psock->sock; + int copied = 0, num_sg; + struct sk_msg_buff *r; + + r = kzalloc(sizeof(struct sk_msg_buff), __GFP_NOWARN | GFP_ATOMIC); + if (unlikely(!r)) + return -EAGAIN; + + if (!sk_rmem_schedule(sk, skb, skb->len)) { + kfree(r); + return -EAGAIN; + } + + sg_init_table(r->sg_data, MAX_SKB_FRAGS); + num_sg = skb_to_sgvec(skb, r->sg_data, 0, skb->len); + if (unlikely(num_sg < 0)) { + kfree(r); + return num_sg; + } + sk_mem_charge(sk, skb->len); + copied = skb->len; + r->sg_start = 0; + r->sg_end = num_sg == MAX_SKB_FRAGS ? 0 : num_sg; + r->skb = skb; + list_add_tail(&r->list, &psock->ingress); + sk->sk_data_ready(sk); + return copied; +} + +static void smap_do_verdict(struct smap_psock *psock, struct sk_buff *skb) +{ + struct smap_psock *peer; + struct sock *sk; + __u32 in; + int rc; + + rc = smap_verdict_func(psock, skb); + switch (rc) { + case __SK_REDIRECT: + sk = do_sk_redirect_map(skb); + if (!sk) { + kfree_skb(skb); + break; + } + + peer = smap_psock_sk(sk); + in = (TCP_SKB_CB(skb)->bpf.flags) & BPF_F_INGRESS; + + if (unlikely(!peer || sock_flag(sk, SOCK_DEAD) || + !test_bit(SMAP_TX_RUNNING, &peer->state))) { + kfree_skb(skb); + break; + } + + if (!in && sock_writeable(sk)) { + skb_set_owner_w(skb, sk); + skb_queue_tail(&peer->rxqueue, skb); + schedule_work(&peer->tx_work); + break; + } else if (in && + atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) { + skb_queue_tail(&peer->rxqueue, skb); + schedule_work(&peer->tx_work); + break; + } + /* Fall through and free skb otherwise */ + case __SK_DROP: + default: + kfree_skb(skb); + } +} + +static void smap_report_sk_error(struct smap_psock *psock, int err) +{ + struct sock *sk = psock->sock; + + sk->sk_err = err; + sk->sk_error_report(sk); +} + +static void smap_read_sock_strparser(struct strparser *strp, + struct sk_buff *skb) +{ + struct smap_psock *psock; + + rcu_read_lock(); + psock = container_of(strp, struct smap_psock, strp); + smap_do_verdict(psock, skb); + rcu_read_unlock(); +} + +/* Called with lock held on socket */ +static void smap_data_ready(struct sock *sk) +{ + struct smap_psock *psock; + + rcu_read_lock(); + psock = smap_psock_sk(sk); + if (likely(psock)) { + write_lock_bh(&sk->sk_callback_lock); + strp_data_ready(&psock->strp); + write_unlock_bh(&sk->sk_callback_lock); + } + rcu_read_unlock(); +} + +static void smap_tx_work(struct work_struct *w) +{ + struct smap_psock *psock; + struct sk_buff *skb; + int rem, off, n; + + psock = container_of(w, struct smap_psock, tx_work); + + /* lock sock to avoid losing sk_socket at some point during loop */ + lock_sock(psock->sock); + if (psock->save_skb) { + skb = psock->save_skb; + rem = psock->save_rem; + off = psock->save_off; + psock->save_skb = NULL; + goto start; + } + + while ((skb = skb_dequeue(&psock->rxqueue))) { + __u32 flags; + + rem = skb->len; + off = 0; +start: + flags = (TCP_SKB_CB(skb)->bpf.flags) & BPF_F_INGRESS; + do { + if (likely(psock->sock->sk_socket)) { + if (flags) + n = smap_do_ingress(psock, skb); + else + n = skb_send_sock_locked(psock->sock, + skb, off, rem); + } else { + n = -EINVAL; + } + + if (n <= 0) { + if (n == -EAGAIN) { + /* Retry when space is available */ + psock->save_skb = skb; + psock->save_rem = rem; + psock->save_off = off; + goto out; + } + /* Hard errors break pipe and stop xmit */ + smap_report_sk_error(psock, n ? -n : EPIPE); + clear_bit(SMAP_TX_RUNNING, &psock->state); + kfree_skb(skb); + goto out; + } + rem -= n; + off += n; + } while (rem); + + if (!flags) + kfree_skb(skb); + } +out: + release_sock(psock->sock); +} + +static void smap_write_space(struct sock *sk) +{ + struct smap_psock *psock; + void (*write_space)(struct sock *sk); + + rcu_read_lock(); + psock = smap_psock_sk(sk); + if (likely(psock && test_bit(SMAP_TX_RUNNING, &psock->state))) + schedule_work(&psock->tx_work); + write_space = psock->save_write_space; + rcu_read_unlock(); + write_space(sk); +} + +static void smap_stop_sock(struct smap_psock *psock, struct sock *sk) +{ + if (!psock->strp_enabled) + return; + sk->sk_data_ready = psock->save_data_ready; + sk->sk_write_space = psock->save_write_space; + psock->save_data_ready = NULL; + psock->save_write_space = NULL; + strp_stop(&psock->strp); + psock->strp_enabled = false; +} + +static void smap_destroy_psock(struct rcu_head *rcu) +{ + struct smap_psock *psock = container_of(rcu, + struct smap_psock, rcu); + + /* Now that a grace period has passed there is no longer + * any reference to this sock in the sockmap so we can + * destroy the psock, strparser, and bpf programs. But, + * because we use workqueue sync operations we can not + * do it in rcu context + */ + schedule_work(&psock->gc_work); +} + +static bool psock_is_smap_sk(struct sock *sk) +{ + return inet_csk(sk)->icsk_ulp_ops == &bpf_tcp_ulp_ops; +} + +static void smap_release_sock(struct smap_psock *psock, struct sock *sock) +{ + if (refcount_dec_and_test(&psock->refcnt)) { + if (psock_is_smap_sk(sock)) + tcp_cleanup_ulp(sock); + write_lock_bh(&sock->sk_callback_lock); + smap_stop_sock(psock, sock); + write_unlock_bh(&sock->sk_callback_lock); + clear_bit(SMAP_TX_RUNNING, &psock->state); + rcu_assign_sk_user_data(sock, NULL); + call_rcu_sched(&psock->rcu, smap_destroy_psock); + } +} + +static int smap_parse_func_strparser(struct strparser *strp, + struct sk_buff *skb) +{ + struct smap_psock *psock; + struct bpf_prog *prog; + int rc; + + rcu_read_lock(); + psock = container_of(strp, struct smap_psock, strp); + prog = READ_ONCE(psock->bpf_parse); + + if (unlikely(!prog)) { + rcu_read_unlock(); + return skb->len; + } + + /* Attach socket for bpf program to use if needed we can do this + * because strparser clones the skb before handing it to a upper + * layer, meaning skb_orphan has been called. We NULL sk on the + * way out to ensure we don't trigger a BUG_ON in skb/sk operations + * later and because we are not charging the memory of this skb to + * any socket yet. + */ + skb->sk = psock->sock; + bpf_compute_data_end_sk_skb(skb); + rc = (*prog->bpf_func)(skb, prog->insnsi); + skb->sk = NULL; + rcu_read_unlock(); + return rc; +} + +static int smap_read_sock_done(struct strparser *strp, int err) +{ + return err; +} + +static int smap_init_sock(struct smap_psock *psock, + struct sock *sk) +{ + static const struct strp_callbacks cb = { + .rcv_msg = smap_read_sock_strparser, + .parse_msg = smap_parse_func_strparser, + .read_sock_done = smap_read_sock_done, + }; + + return strp_init(&psock->strp, sk, &cb); +} + +static void smap_init_progs(struct smap_psock *psock, + struct bpf_prog *verdict, + struct bpf_prog *parse) +{ + struct bpf_prog *orig_parse, *orig_verdict; + + orig_parse = xchg(&psock->bpf_parse, parse); + orig_verdict = xchg(&psock->bpf_verdict, verdict); + + if (orig_verdict) + bpf_prog_put(orig_verdict); + if (orig_parse) + bpf_prog_put(orig_parse); +} + +static void smap_start_sock(struct smap_psock *psock, struct sock *sk) +{ + if (sk->sk_data_ready == smap_data_ready) + return; + psock->save_data_ready = sk->sk_data_ready; + psock->save_write_space = sk->sk_write_space; + sk->sk_data_ready = smap_data_ready; + sk->sk_write_space = smap_write_space; + psock->strp_enabled = true; +} + +static void sock_map_remove_complete(struct bpf_stab *stab) +{ + bpf_map_area_free(stab->sock_map); + kfree(stab); +} + +static void smap_gc_work(struct work_struct *w) +{ + struct smap_psock_map_entry *e, *tmp; + struct sk_msg_buff *md, *mtmp; + struct smap_psock *psock; + + psock = container_of(w, struct smap_psock, gc_work); + + /* no callback lock needed because we already detached sockmap ops */ + if (psock->strp_enabled) + strp_done(&psock->strp); + + cancel_work_sync(&psock->tx_work); + __skb_queue_purge(&psock->rxqueue); + + /* At this point all strparser and xmit work must be complete */ + if (psock->bpf_parse) + bpf_prog_put(psock->bpf_parse); + if (psock->bpf_verdict) + bpf_prog_put(psock->bpf_verdict); + if (psock->bpf_tx_msg) + bpf_prog_put(psock->bpf_tx_msg); + + if (psock->cork) { + free_start_sg(psock->sock, psock->cork, true); + kfree(psock->cork); + } + + list_for_each_entry_safe(md, mtmp, &psock->ingress, list) { + list_del(&md->list); + free_start_sg(psock->sock, md, true); + kfree(md); + } + + list_for_each_entry_safe(e, tmp, &psock->maps, list) { + list_del(&e->list); + kfree(e); + } + + if (psock->sk_redir) + sock_put(psock->sk_redir); + + sock_put(psock->sock); + kfree(psock); +} + +static struct smap_psock *smap_init_psock(struct sock *sock, int node) +{ + struct smap_psock *psock; + + psock = kzalloc_node(sizeof(struct smap_psock), + GFP_ATOMIC | __GFP_NOWARN, + node); + if (!psock) + return ERR_PTR(-ENOMEM); + + psock->eval = __SK_NONE; + psock->sock = sock; + skb_queue_head_init(&psock->rxqueue); + INIT_WORK(&psock->tx_work, smap_tx_work); + INIT_WORK(&psock->gc_work, smap_gc_work); + INIT_LIST_HEAD(&psock->maps); + INIT_LIST_HEAD(&psock->ingress); + refcount_set(&psock->refcnt, 1); + spin_lock_init(&psock->maps_lock); + + rcu_assign_sk_user_data(sock, psock); + sock_hold(sock); + return psock; +} + +static struct bpf_map *sock_map_alloc(union bpf_attr *attr) +{ + struct bpf_stab *stab; + u64 cost; + int err; + + if (!capable(CAP_NET_ADMIN)) + return ERR_PTR(-EPERM); + + /* check sanity of attributes */ + if (attr->max_entries == 0 || attr->key_size != 4 || + attr->value_size != 4 || attr->map_flags & ~SOCK_CREATE_FLAG_MASK) + return ERR_PTR(-EINVAL); + + err = bpf_tcp_ulp_register(); + if (err && err != -EEXIST) + return ERR_PTR(err); + + stab = kzalloc(sizeof(*stab), GFP_USER); + if (!stab) + return ERR_PTR(-ENOMEM); + + bpf_map_init_from_attr(&stab->map, attr); + raw_spin_lock_init(&stab->lock); + + /* make sure page count doesn't overflow */ + cost = (u64) stab->map.max_entries * sizeof(struct sock *); + err = -EINVAL; + if (cost >= U32_MAX - PAGE_SIZE) + goto free_stab; + + stab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT; + + /* if map size is larger than memlock limit, reject it early */ + err = bpf_map_precharge_memlock(stab->map.pages); + if (err) + goto free_stab; + + err = -ENOMEM; + stab->sock_map = bpf_map_area_alloc(stab->map.max_entries * + sizeof(struct sock *), + stab->map.numa_node); + if (!stab->sock_map) + goto free_stab; + + return &stab->map; +free_stab: + kfree(stab); + return ERR_PTR(err); +} + +static void smap_list_map_remove(struct smap_psock *psock, + struct sock **entry) +{ + struct smap_psock_map_entry *e, *tmp; + + spin_lock_bh(&psock->maps_lock); + list_for_each_entry_safe(e, tmp, &psock->maps, list) { + if (e->entry == entry) { + list_del(&e->list); + kfree(e); + } + } + spin_unlock_bh(&psock->maps_lock); +} + +static void smap_list_hash_remove(struct smap_psock *psock, + struct htab_elem *hash_link) +{ + struct smap_psock_map_entry *e, *tmp; + + spin_lock_bh(&psock->maps_lock); + list_for_each_entry_safe(e, tmp, &psock->maps, list) { + struct htab_elem *c = rcu_dereference(e->hash_link); + + if (c == hash_link) { + list_del(&e->list); + kfree(e); + } + } + spin_unlock_bh(&psock->maps_lock); +} + +static void sock_map_free(struct bpf_map *map) +{ + struct bpf_stab *stab = container_of(map, struct bpf_stab, map); + int i; + + synchronize_rcu(); + + /* At this point no update, lookup or delete operations can happen. + * However, be aware we can still get a socket state event updates, + * and data ready callabacks that reference the psock from sk_user_data + * Also psock worker threads are still in-flight. So smap_release_sock + * will only free the psock after cancel_sync on the worker threads + * and a grace period expire to ensure psock is really safe to remove. + */ + rcu_read_lock(); + raw_spin_lock_bh(&stab->lock); + for (i = 0; i < stab->map.max_entries; i++) { + struct smap_psock *psock; + struct sock *sock; + + sock = stab->sock_map[i]; + if (!sock) + continue; + stab->sock_map[i] = NULL; + psock = smap_psock_sk(sock); + /* This check handles a racing sock event that can get the + * sk_callback_lock before this case but after xchg happens + * causing the refcnt to hit zero and sock user data (psock) + * to be null and queued for garbage collection. + */ + if (likely(psock)) { + smap_list_map_remove(psock, &stab->sock_map[i]); + smap_release_sock(psock, sock); + } + } + raw_spin_unlock_bh(&stab->lock); + rcu_read_unlock(); + + sock_map_remove_complete(stab); +} + +static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next_key) +{ + struct bpf_stab *stab = container_of(map, struct bpf_stab, map); + u32 i = key ? *(u32 *)key : U32_MAX; + u32 *next = (u32 *)next_key; + + if (i >= stab->map.max_entries) { + *next = 0; + return 0; + } + + if (i == stab->map.max_entries - 1) + return -ENOENT; + + *next = i + 1; + return 0; +} + +struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key) +{ + struct bpf_stab *stab = container_of(map, struct bpf_stab, map); + + if (key >= map->max_entries) + return NULL; + + return READ_ONCE(stab->sock_map[key]); +} + +static int sock_map_delete_elem(struct bpf_map *map, void *key) +{ + struct bpf_stab *stab = container_of(map, struct bpf_stab, map); + struct smap_psock *psock; + int k = *(u32 *)key; + struct sock *sock; + + if (k >= map->max_entries) + return -EINVAL; + + raw_spin_lock_bh(&stab->lock); + sock = stab->sock_map[k]; + stab->sock_map[k] = NULL; + raw_spin_unlock_bh(&stab->lock); + if (!sock) + return -EINVAL; + + psock = smap_psock_sk(sock); + if (!psock) + return 0; + if (psock->bpf_parse) { + write_lock_bh(&sock->sk_callback_lock); + smap_stop_sock(psock, sock); + write_unlock_bh(&sock->sk_callback_lock); + } + smap_list_map_remove(psock, &stab->sock_map[k]); + smap_release_sock(psock, sock); + return 0; +} + +/* Locking notes: Concurrent updates, deletes, and lookups are allowed and are + * done inside rcu critical sections. This ensures on updates that the psock + * will not be released via smap_release_sock() until concurrent updates/deletes + * complete. All operations operate on sock_map using cmpxchg and xchg + * operations to ensure we do not get stale references. Any reads into the + * map must be done with READ_ONCE() because of this. + * + * A psock is destroyed via call_rcu and after any worker threads are cancelled + * and syncd so we are certain all references from the update/lookup/delete + * operations as well as references in the data path are no longer in use. + * + * Psocks may exist in multiple maps, but only a single set of parse/verdict + * programs may be inherited from the maps it belongs to. A reference count + * is kept with the total number of references to the psock from all maps. The + * psock will not be released until this reaches zero. The psock and sock + * user data data use the sk_callback_lock to protect critical data structures + * from concurrent access. This allows us to avoid two updates from modifying + * the user data in sock and the lock is required anyways for modifying + * callbacks, we simply increase its scope slightly. + * + * Rules to follow, + * - psock must always be read inside RCU critical section + * - sk_user_data must only be modified inside sk_callback_lock and read + * inside RCU critical section. + * - psock->maps list must only be read & modified inside sk_callback_lock + * - sock_map must use READ_ONCE and (cmp)xchg operations + * - BPF verdict/parse programs must use READ_ONCE and xchg operations + */ + +static int __sock_map_ctx_update_elem(struct bpf_map *map, + struct bpf_sock_progs *progs, + struct sock *sock, + void *key) +{ + struct bpf_prog *verdict, *parse, *tx_msg; + struct smap_psock *psock; + bool new = false; + int err = 0; + + /* 1. If sock map has BPF programs those will be inherited by the + * sock being added. If the sock is already attached to BPF programs + * this results in an error. + */ + verdict = READ_ONCE(progs->bpf_verdict); + parse = READ_ONCE(progs->bpf_parse); + tx_msg = READ_ONCE(progs->bpf_tx_msg); + + if (parse && verdict) { + /* bpf prog refcnt may be zero if a concurrent attach operation + * removes the program after the above READ_ONCE() but before + * we increment the refcnt. If this is the case abort with an + * error. + */ + verdict = bpf_prog_inc_not_zero(verdict); + if (IS_ERR(verdict)) + return PTR_ERR(verdict); + + parse = bpf_prog_inc_not_zero(parse); + if (IS_ERR(parse)) { + bpf_prog_put(verdict); + return PTR_ERR(parse); + } + } + + if (tx_msg) { + tx_msg = bpf_prog_inc_not_zero(tx_msg); + if (IS_ERR(tx_msg)) { + if (parse && verdict) { + bpf_prog_put(parse); + bpf_prog_put(verdict); + } + return PTR_ERR(tx_msg); + } + } + + psock = smap_psock_sk(sock); + + /* 2. Do not allow inheriting programs if psock exists and has + * already inherited programs. This would create confusion on + * which parser/verdict program is running. If no psock exists + * create one. Inside sk_callback_lock to ensure concurrent create + * doesn't update user data. + */ + if (psock) { + if (!psock_is_smap_sk(sock)) { + err = -EBUSY; + goto out_progs; + } + if (READ_ONCE(psock->bpf_parse) && parse) { + err = -EBUSY; + goto out_progs; + } + if (READ_ONCE(psock->bpf_tx_msg) && tx_msg) { + err = -EBUSY; + goto out_progs; + } + if (!refcount_inc_not_zero(&psock->refcnt)) { + err = -EAGAIN; + goto out_progs; + } + } else { + psock = smap_init_psock(sock, map->numa_node); + if (IS_ERR(psock)) { + err = PTR_ERR(psock); + goto out_progs; + } + + set_bit(SMAP_TX_RUNNING, &psock->state); + new = true; + } + + /* 3. At this point we have a reference to a valid psock that is + * running. Attach any BPF programs needed. + */ + if (tx_msg) + bpf_tcp_msg_add(psock, sock, tx_msg); + if (new) { + err = tcp_set_ulp_id(sock, TCP_ULP_BPF); + if (err) + goto out_free; + } + + if (parse && verdict && !psock->strp_enabled) { + err = smap_init_sock(psock, sock); + if (err) + goto out_free; + smap_init_progs(psock, verdict, parse); + write_lock_bh(&sock->sk_callback_lock); + smap_start_sock(psock, sock); + write_unlock_bh(&sock->sk_callback_lock); + } + + return err; +out_free: + smap_release_sock(psock, sock); +out_progs: + if (parse && verdict) { + bpf_prog_put(parse); + bpf_prog_put(verdict); + } + if (tx_msg) + bpf_prog_put(tx_msg); + return err; +} + +static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, + struct bpf_map *map, + void *key, u64 flags) +{ + struct bpf_stab *stab = container_of(map, struct bpf_stab, map); + struct bpf_sock_progs *progs = &stab->progs; + struct sock *osock, *sock = skops->sk; + struct smap_psock_map_entry *e; + struct smap_psock *psock; + u32 i = *(u32 *)key; + int err; + + if (unlikely(flags > BPF_EXIST)) + return -EINVAL; + if (unlikely(i >= stab->map.max_entries)) + return -E2BIG; + + e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN); + if (!e) + return -ENOMEM; + + err = __sock_map_ctx_update_elem(map, progs, sock, key); + if (err) + goto out; + + /* psock guaranteed to be present. */ + psock = smap_psock_sk(sock); + raw_spin_lock_bh(&stab->lock); + osock = stab->sock_map[i]; + if (osock && flags == BPF_NOEXIST) { + err = -EEXIST; + goto out_unlock; + } + if (!osock && flags == BPF_EXIST) { + err = -ENOENT; + goto out_unlock; + } + + e->entry = &stab->sock_map[i]; + e->map = map; + spin_lock_bh(&psock->maps_lock); + list_add_tail(&e->list, &psock->maps); + spin_unlock_bh(&psock->maps_lock); + + stab->sock_map[i] = sock; + if (osock) { + psock = smap_psock_sk(osock); + smap_list_map_remove(psock, &stab->sock_map[i]); + smap_release_sock(psock, osock); + } + raw_spin_unlock_bh(&stab->lock); + return 0; +out_unlock: + smap_release_sock(psock, sock); + raw_spin_unlock_bh(&stab->lock); +out: + kfree(e); + return err; +} + +int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type) +{ + struct bpf_sock_progs *progs; + struct bpf_prog *orig; + + if (map->map_type == BPF_MAP_TYPE_SOCKMAP) { + struct bpf_stab *stab = container_of(map, struct bpf_stab, map); + + progs = &stab->progs; + } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH) { + struct bpf_htab *htab = container_of(map, struct bpf_htab, map); + + progs = &htab->progs; + } else { + return -EINVAL; + } + + switch (type) { + case BPF_SK_MSG_VERDICT: + orig = xchg(&progs->bpf_tx_msg, prog); + break; + case BPF_SK_SKB_STREAM_PARSER: + orig = xchg(&progs->bpf_parse, prog); + break; + case BPF_SK_SKB_STREAM_VERDICT: + orig = xchg(&progs->bpf_verdict, prog); + break; + default: + return -EOPNOTSUPP; + } + + if (orig) + bpf_prog_put(orig); + + return 0; +} + +int sockmap_get_from_fd(const union bpf_attr *attr, int type, + struct bpf_prog *prog) +{ + int ufd = attr->target_fd; + struct bpf_map *map; + struct fd f; + int err; + + f = fdget(ufd); + map = __bpf_map_get(f); + if (IS_ERR(map)) + return PTR_ERR(map); + + err = sock_map_prog(map, prog, attr->attach_type); + fdput(f); + return err; +} + +static void *sock_map_lookup(struct bpf_map *map, void *key) +{ + return NULL; +} + +static int sock_map_update_elem(struct bpf_map *map, + void *key, void *value, u64 flags) +{ + struct bpf_sock_ops_kern skops; + u32 fd = *(u32 *)value; + struct socket *socket; + int err; + + socket = sockfd_lookup(fd, &err); + if (!socket) + return err; + + skops.sk = socket->sk; + if (!skops.sk) { + fput(socket->file); + return -EINVAL; + } + + /* ULPs are currently supported only for TCP sockets in ESTABLISHED + * state. + */ + if (skops.sk->sk_type != SOCK_STREAM || + skops.sk->sk_protocol != IPPROTO_TCP || + skops.sk->sk_state != TCP_ESTABLISHED) { + fput(socket->file); + return -EOPNOTSUPP; + } + + lock_sock(skops.sk); + preempt_disable(); + rcu_read_lock(); + err = sock_map_ctx_update_elem(&skops, map, key, flags); + rcu_read_unlock(); + preempt_enable(); + release_sock(skops.sk); + fput(socket->file); + return err; +} + +static void sock_map_release(struct bpf_map *map) +{ + struct bpf_sock_progs *progs; + struct bpf_prog *orig; + + if (map->map_type == BPF_MAP_TYPE_SOCKMAP) { + struct bpf_stab *stab = container_of(map, struct bpf_stab, map); + + progs = &stab->progs; + } else { + struct bpf_htab *htab = container_of(map, struct bpf_htab, map); + + progs = &htab->progs; + } + + orig = xchg(&progs->bpf_parse, NULL); + if (orig) + bpf_prog_put(orig); + orig = xchg(&progs->bpf_verdict, NULL); + if (orig) + bpf_prog_put(orig); + + orig = xchg(&progs->bpf_tx_msg, NULL); + if (orig) + bpf_prog_put(orig); +} + +static struct bpf_map *sock_hash_alloc(union bpf_attr *attr) +{ + struct bpf_htab *htab; + int i, err; + u64 cost; + + if (!capable(CAP_NET_ADMIN)) + return ERR_PTR(-EPERM); + + /* check sanity of attributes */ + if (attr->max_entries == 0 || + attr->key_size == 0 || + attr->value_size != 4 || + attr->map_flags & ~SOCK_CREATE_FLAG_MASK) + return ERR_PTR(-EINVAL); + + if (attr->key_size > MAX_BPF_STACK) + /* eBPF programs initialize keys on stack, so they cannot be + * larger than max stack size + */ + return ERR_PTR(-E2BIG); + + err = bpf_tcp_ulp_register(); + if (err && err != -EEXIST) + return ERR_PTR(err); + + htab = kzalloc(sizeof(*htab), GFP_USER); + if (!htab) + return ERR_PTR(-ENOMEM); + + bpf_map_init_from_attr(&htab->map, attr); + + htab->n_buckets = roundup_pow_of_two(htab->map.max_entries); + htab->elem_size = sizeof(struct htab_elem) + + round_up(htab->map.key_size, 8); + err = -EINVAL; + if (htab->n_buckets == 0 || + htab->n_buckets > U32_MAX / sizeof(struct bucket)) + goto free_htab; + + cost = (u64) htab->n_buckets * sizeof(struct bucket) + + (u64) htab->elem_size * htab->map.max_entries; + + if (cost >= U32_MAX - PAGE_SIZE) + goto free_htab; + + htab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT; + err = bpf_map_precharge_memlock(htab->map.pages); + if (err) + goto free_htab; + + err = -ENOMEM; + htab->buckets = bpf_map_area_alloc( + htab->n_buckets * sizeof(struct bucket), + htab->map.numa_node); + if (!htab->buckets) + goto free_htab; + + for (i = 0; i < htab->n_buckets; i++) { + INIT_HLIST_HEAD(&htab->buckets[i].head); + raw_spin_lock_init(&htab->buckets[i].lock); + } + + return &htab->map; +free_htab: + kfree(htab); + return ERR_PTR(err); +} + +static void __bpf_htab_free(struct rcu_head *rcu) +{ + struct bpf_htab *htab; + + htab = container_of(rcu, struct bpf_htab, rcu); + bpf_map_area_free(htab->buckets); + kfree(htab); +} + +static void sock_hash_free(struct bpf_map *map) +{ + struct bpf_htab *htab = container_of(map, struct bpf_htab, map); + int i; + + synchronize_rcu(); + + /* At this point no update, lookup or delete operations can happen. + * However, be aware we can still get a socket state event updates, + * and data ready callabacks that reference the psock from sk_user_data + * Also psock worker threads are still in-flight. So smap_release_sock + * will only free the psock after cancel_sync on the worker threads + * and a grace period expire to ensure psock is really safe to remove. + */ + rcu_read_lock(); + for (i = 0; i < htab->n_buckets; i++) { + struct bucket *b = __select_bucket(htab, i); + struct hlist_head *head; + struct hlist_node *n; + struct htab_elem *l; + + raw_spin_lock_bh(&b->lock); + head = &b->head; + hlist_for_each_entry_safe(l, n, head, hash_node) { + struct sock *sock = l->sk; + struct smap_psock *psock; + + hlist_del_rcu(&l->hash_node); + psock = smap_psock_sk(sock); + /* This check handles a racing sock event that can get + * the sk_callback_lock before this case but after xchg + * causing the refcnt to hit zero and sock user data + * (psock) to be null and queued for garbage collection. + */ + if (likely(psock)) { + smap_list_hash_remove(psock, l); + smap_release_sock(psock, sock); + } + free_htab_elem(htab, l); + } + raw_spin_unlock_bh(&b->lock); + } + rcu_read_unlock(); + call_rcu(&htab->rcu, __bpf_htab_free); +} + +static struct htab_elem *alloc_sock_hash_elem(struct bpf_htab *htab, + void *key, u32 key_size, u32 hash, + struct sock *sk, + struct htab_elem *old_elem) +{ + struct htab_elem *l_new; + + if (atomic_inc_return(&htab->count) > htab->map.max_entries) { + if (!old_elem) { + atomic_dec(&htab->count); + return ERR_PTR(-E2BIG); + } + } + l_new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN, + htab->map.numa_node); + if (!l_new) { + atomic_dec(&htab->count); + return ERR_PTR(-ENOMEM); + } + + memcpy(l_new->key, key, key_size); + l_new->sk = sk; + l_new->hash = hash; + return l_new; +} + +static inline u32 htab_map_hash(const void *key, u32 key_len) +{ + return jhash(key, key_len, 0); +} + +static int sock_hash_get_next_key(struct bpf_map *map, + void *key, void *next_key) +{ + struct bpf_htab *htab = container_of(map, struct bpf_htab, map); + struct htab_elem *l, *next_l; + struct hlist_head *h; + u32 hash, key_size; + int i = 0; + + WARN_ON_ONCE(!rcu_read_lock_held()); + + key_size = map->key_size; + if (!key) + goto find_first_elem; + hash = htab_map_hash(key, key_size); + h = select_bucket(htab, hash); + + l = lookup_elem_raw(h, hash, key, key_size); + if (!l) + goto find_first_elem; + next_l = hlist_entry_safe( + rcu_dereference_raw(hlist_next_rcu(&l->hash_node)), + struct htab_elem, hash_node); + if (next_l) { + memcpy(next_key, next_l->key, key_size); + return 0; + } + + /* no more elements in this hash list, go to the next bucket */ + i = hash & (htab->n_buckets - 1); + i++; + +find_first_elem: + /* iterate over buckets */ + for (; i < htab->n_buckets; i++) { + h = select_bucket(htab, i); + + /* pick first element in the bucket */ + next_l = hlist_entry_safe( + rcu_dereference_raw(hlist_first_rcu(h)), + struct htab_elem, hash_node); + if (next_l) { + /* if it's not empty, just return it */ + memcpy(next_key, next_l->key, key_size); + return 0; + } + } + + /* iterated over all buckets and all elements */ + return -ENOENT; +} + +static int sock_hash_ctx_update_elem(struct bpf_sock_ops_kern *skops, + struct bpf_map *map, + void *key, u64 map_flags) +{ + struct bpf_htab *htab = container_of(map, struct bpf_htab, map); + struct bpf_sock_progs *progs = &htab->progs; + struct htab_elem *l_new = NULL, *l_old; + struct smap_psock_map_entry *e = NULL; + struct hlist_head *head; + struct smap_psock *psock; + u32 key_size, hash; + struct sock *sock; + struct bucket *b; + int err; + + sock = skops->sk; + + if (sock->sk_type != SOCK_STREAM || + sock->sk_protocol != IPPROTO_TCP) + return -EOPNOTSUPP; + + if (unlikely(map_flags > BPF_EXIST)) + return -EINVAL; + + e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN); + if (!e) + return -ENOMEM; + + WARN_ON_ONCE(!rcu_read_lock_held()); + key_size = map->key_size; + hash = htab_map_hash(key, key_size); + b = __select_bucket(htab, hash); + head = &b->head; + + err = __sock_map_ctx_update_elem(map, progs, sock, key); + if (err) + goto err; + + /* psock is valid here because otherwise above *ctx_update_elem would + * have thrown an error. It is safe to skip error check. + */ + psock = smap_psock_sk(sock); + raw_spin_lock_bh(&b->lock); + l_old = lookup_elem_raw(head, hash, key, key_size); + if (l_old && map_flags == BPF_NOEXIST) { + err = -EEXIST; + goto bucket_err; + } + if (!l_old && map_flags == BPF_EXIST) { + err = -ENOENT; + goto bucket_err; + } + + l_new = alloc_sock_hash_elem(htab, key, key_size, hash, sock, l_old); + if (IS_ERR(l_new)) { + err = PTR_ERR(l_new); + goto bucket_err; + } + + rcu_assign_pointer(e->hash_link, l_new); + e->map = map; + spin_lock_bh(&psock->maps_lock); + list_add_tail(&e->list, &psock->maps); + spin_unlock_bh(&psock->maps_lock); + + /* add new element to the head of the list, so that + * concurrent search will find it before old elem + */ + hlist_add_head_rcu(&l_new->hash_node, head); + if (l_old) { + psock = smap_psock_sk(l_old->sk); + + hlist_del_rcu(&l_old->hash_node); + smap_list_hash_remove(psock, l_old); + smap_release_sock(psock, l_old->sk); + free_htab_elem(htab, l_old); + } + raw_spin_unlock_bh(&b->lock); + return 0; +bucket_err: + smap_release_sock(psock, sock); + raw_spin_unlock_bh(&b->lock); +err: + kfree(e); + return err; +} + +static int sock_hash_update_elem(struct bpf_map *map, + void *key, void *value, u64 flags) +{ + struct bpf_sock_ops_kern skops; + u32 fd = *(u32 *)value; + struct socket *socket; + int err; + + socket = sockfd_lookup(fd, &err); + if (!socket) + return err; + + skops.sk = socket->sk; + if (!skops.sk) { + fput(socket->file); + return -EINVAL; + } + + /* ULPs are currently supported only for TCP sockets in ESTABLISHED + * state. + */ + if (skops.sk->sk_type != SOCK_STREAM || + skops.sk->sk_protocol != IPPROTO_TCP || + skops.sk->sk_state != TCP_ESTABLISHED) { + fput(socket->file); + return -EOPNOTSUPP; + } + + lock_sock(skops.sk); + preempt_disable(); + rcu_read_lock(); + err = sock_hash_ctx_update_elem(&skops, map, key, flags); + rcu_read_unlock(); + preempt_enable(); + release_sock(skops.sk); + fput(socket->file); + return err; +} + +static int sock_hash_delete_elem(struct bpf_map *map, void *key) +{ + struct bpf_htab *htab = container_of(map, struct bpf_htab, map); + struct hlist_head *head; + struct bucket *b; + struct htab_elem *l; + u32 hash, key_size; + int ret = -ENOENT; + + key_size = map->key_size; + hash = htab_map_hash(key, key_size); + b = __select_bucket(htab, hash); + head = &b->head; + + raw_spin_lock_bh(&b->lock); + l = lookup_elem_raw(head, hash, key, key_size); + if (l) { + struct sock *sock = l->sk; + struct smap_psock *psock; + + hlist_del_rcu(&l->hash_node); + psock = smap_psock_sk(sock); + /* This check handles a racing sock event that can get the + * sk_callback_lock before this case but after xchg happens + * causing the refcnt to hit zero and sock user data (psock) + * to be null and queued for garbage collection. + */ + if (likely(psock)) { + smap_list_hash_remove(psock, l); + smap_release_sock(psock, sock); + } + free_htab_elem(htab, l); + ret = 0; + } + raw_spin_unlock_bh(&b->lock); + return ret; +} + +struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key) +{ + struct bpf_htab *htab = container_of(map, struct bpf_htab, map); + struct hlist_head *head; + struct htab_elem *l; + u32 key_size, hash; + struct bucket *b; + struct sock *sk; + + key_size = map->key_size; + hash = htab_map_hash(key, key_size); + b = __select_bucket(htab, hash); + head = &b->head; + + l = lookup_elem_raw(head, hash, key, key_size); + sk = l ? l->sk : NULL; + return sk; +} + +const struct bpf_map_ops sock_map_ops = { + .map_alloc = sock_map_alloc, + .map_free = sock_map_free, + .map_lookup_elem = sock_map_lookup, + .map_get_next_key = sock_map_get_next_key, + .map_update_elem = sock_map_update_elem, + .map_delete_elem = sock_map_delete_elem, + .map_release_uref = sock_map_release, + .map_check_btf = map_check_no_btf, +}; + +const struct bpf_map_ops sock_hash_ops = { + .map_alloc = sock_hash_alloc, + .map_free = sock_hash_free, + .map_lookup_elem = sock_map_lookup, + .map_get_next_key = sock_hash_get_next_key, + .map_update_elem = sock_hash_update_elem, + .map_delete_elem = sock_hash_delete_elem, + .map_release_uref = sock_map_release, + .map_check_btf = map_check_no_btf, +}; + +static bool bpf_is_valid_sock_op(struct bpf_sock_ops_kern *ops) +{ + return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB || + ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB; +} +BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, bpf_sock, + struct bpf_map *, map, void *, key, u64, flags) +{ + WARN_ON_ONCE(!rcu_read_lock_held()); + + /* ULPs are currently supported only for TCP sockets in ESTABLISHED + * state. This checks that the sock ops triggering the update is + * one indicating we are (or will be soon) in an ESTABLISHED state. + */ + if (!bpf_is_valid_sock_op(bpf_sock)) + return -EOPNOTSUPP; + return sock_map_ctx_update_elem(bpf_sock, map, key, flags); +} + +const struct bpf_func_proto bpf_sock_map_update_proto = { + .func = bpf_sock_map_update, + .gpl_only = false, + .pkt_access = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_CONST_MAP_PTR, + .arg3_type = ARG_PTR_TO_MAP_KEY, + .arg4_type = ARG_ANYTHING, +}; + +BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, bpf_sock, + struct bpf_map *, map, void *, key, u64, flags) +{ + WARN_ON_ONCE(!rcu_read_lock_held()); + + if (!bpf_is_valid_sock_op(bpf_sock)) + return -EOPNOTSUPP; + return sock_hash_ctx_update_elem(bpf_sock, map, key, flags); +} + +const struct bpf_func_proto bpf_sock_hash_update_proto = { + .func = bpf_sock_hash_update, + .gpl_only = false, + .pkt_access = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_CONST_MAP_PTR, + .arg3_type = ARG_PTR_TO_MAP_KEY, + .arg4_type = ARG_ANYTHING, +}; |