diff options
Diffstat (limited to 'net/phonet/pep.c')
| -rw-r--r-- | net/phonet/pep.c | 1365 |
1 files changed, 1365 insertions, 0 deletions
diff --git a/net/phonet/pep.c b/net/phonet/pep.c new file mode 100644 index 000000000..65d463ad8 --- /dev/null +++ b/net/phonet/pep.c @@ -0,0 +1,1365 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * File: pep.c + * + * Phonet pipe protocol end point socket + * + * Copyright (C) 2008 Nokia Corporation. + * + * Author: Rémi Denis-Courmont + */ + +#include <linux/kernel.h> +#include <linux/sched/signal.h> +#include <linux/slab.h> +#include <linux/socket.h> +#include <net/sock.h> +#include <net/tcp_states.h> +#include <asm/ioctls.h> + +#include <linux/phonet.h> +#include <linux/module.h> +#include <net/phonet/phonet.h> +#include <net/phonet/pep.h> +#include <net/phonet/gprs.h> + +/* sk_state values: + * TCP_CLOSE sock not in use yet + * TCP_CLOSE_WAIT disconnected pipe + * TCP_LISTEN listening pipe endpoint + * TCP_SYN_RECV connected pipe in disabled state + * TCP_ESTABLISHED connected pipe in enabled state + * + * pep_sock locking: + * - sk_state, hlist: sock lock needed + * - listener: read only + * - pipe_handle: read only + */ + +#define CREDITS_MAX 10 +#define CREDITS_THR 7 + +#define pep_sb_size(s) (((s) + 5) & ~3) /* 2-bytes head, 32-bits aligned */ + +/* Get the next TLV sub-block. */ +static unsigned char *pep_get_sb(struct sk_buff *skb, u8 *ptype, u8 *plen, + void *buf) +{ + void *data = NULL; + struct { + u8 sb_type; + u8 sb_len; + } *ph, h; + int buflen = *plen; + + ph = skb_header_pointer(skb, 0, 2, &h); + if (ph == NULL || ph->sb_len < 2 || !pskb_may_pull(skb, ph->sb_len)) + return NULL; + ph->sb_len -= 2; + *ptype = ph->sb_type; + *plen = ph->sb_len; + + if (buflen > ph->sb_len) + buflen = ph->sb_len; + data = skb_header_pointer(skb, 2, buflen, buf); + __skb_pull(skb, 2 + ph->sb_len); + return data; +} + +static struct sk_buff *pep_alloc_skb(struct sock *sk, const void *payload, + int len, gfp_t priority) +{ + struct sk_buff *skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority); + if (!skb) + return NULL; + skb_set_owner_w(skb, sk); + + skb_reserve(skb, MAX_PNPIPE_HEADER); + __skb_put(skb, len); + skb_copy_to_linear_data(skb, payload, len); + __skb_push(skb, sizeof(struct pnpipehdr)); + skb_reset_transport_header(skb); + return skb; +} + +static int pep_reply(struct sock *sk, struct sk_buff *oskb, u8 code, + const void *data, int len, gfp_t priority) +{ + const struct pnpipehdr *oph = pnp_hdr(oskb); + struct pnpipehdr *ph; + struct sk_buff *skb; + struct sockaddr_pn peer; + + skb = pep_alloc_skb(sk, data, len, priority); + if (!skb) + return -ENOMEM; + + ph = pnp_hdr(skb); + ph->utid = oph->utid; + ph->message_id = oph->message_id + 1; /* REQ -> RESP */ + ph->pipe_handle = oph->pipe_handle; + ph->error_code = code; + + pn_skb_get_src_sockaddr(oskb, &peer); + return pn_skb_send(sk, skb, &peer); +} + +static int pep_indicate(struct sock *sk, u8 id, u8 code, + const void *data, int len, gfp_t priority) +{ + struct pep_sock *pn = pep_sk(sk); + struct pnpipehdr *ph; + struct sk_buff *skb; + + skb = pep_alloc_skb(sk, data, len, priority); + if (!skb) + return -ENOMEM; + + ph = pnp_hdr(skb); + ph->utid = 0; + ph->message_id = id; + ph->pipe_handle = pn->pipe_handle; + ph->error_code = code; + return pn_skb_send(sk, skb, NULL); +} + +#define PAD 0x00 + +static int pipe_handler_request(struct sock *sk, u8 id, u8 code, + const void *data, int len) +{ + struct pep_sock *pn = pep_sk(sk); + struct pnpipehdr *ph; + struct sk_buff *skb; + + skb = pep_alloc_skb(sk, data, len, GFP_KERNEL); + if (!skb) + return -ENOMEM; + + ph = pnp_hdr(skb); + ph->utid = id; /* whatever */ + ph->message_id = id; + ph->pipe_handle = pn->pipe_handle; + ph->error_code = code; + return pn_skb_send(sk, skb, NULL); +} + +static int pipe_handler_send_created_ind(struct sock *sk) +{ + struct pep_sock *pn = pep_sk(sk); + u8 data[4] = { + PN_PIPE_SB_NEGOTIATED_FC, pep_sb_size(2), + pn->tx_fc, pn->rx_fc, + }; + + return pep_indicate(sk, PNS_PIPE_CREATED_IND, 1 /* sub-blocks */, + data, 4, GFP_ATOMIC); +} + +static int pep_accept_conn(struct sock *sk, struct sk_buff *skb) +{ + static const u8 data[20] = { + PAD, PAD, PAD, 2 /* sub-blocks */, + PN_PIPE_SB_REQUIRED_FC_TX, pep_sb_size(5), 3, PAD, + PN_MULTI_CREDIT_FLOW_CONTROL, + PN_ONE_CREDIT_FLOW_CONTROL, + PN_LEGACY_FLOW_CONTROL, + PAD, + PN_PIPE_SB_PREFERRED_FC_RX, pep_sb_size(5), 3, PAD, + PN_MULTI_CREDIT_FLOW_CONTROL, + PN_ONE_CREDIT_FLOW_CONTROL, + PN_LEGACY_FLOW_CONTROL, + PAD, + }; + + might_sleep(); + return pep_reply(sk, skb, PN_PIPE_NO_ERROR, data, sizeof(data), + GFP_KERNEL); +} + +static int pep_reject_conn(struct sock *sk, struct sk_buff *skb, u8 code, + gfp_t priority) +{ + static const u8 data[4] = { PAD, PAD, PAD, 0 /* sub-blocks */ }; + WARN_ON(code == PN_PIPE_NO_ERROR); + return pep_reply(sk, skb, code, data, sizeof(data), priority); +} + +/* Control requests are not sent by the pipe service and have a specific + * message format. */ +static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code, + gfp_t priority) +{ + const struct pnpipehdr *oph = pnp_hdr(oskb); + struct sk_buff *skb; + struct pnpipehdr *ph; + struct sockaddr_pn dst; + u8 data[4] = { + oph->pep_type, /* PEP type */ + code, /* error code, at an unusual offset */ + PAD, PAD, + }; + + skb = pep_alloc_skb(sk, data, 4, priority); + if (!skb) + return -ENOMEM; + + ph = pnp_hdr(skb); + ph->utid = oph->utid; + ph->message_id = PNS_PEP_CTRL_RESP; + ph->pipe_handle = oph->pipe_handle; + ph->data0 = oph->data[0]; /* CTRL id */ + + pn_skb_get_src_sockaddr(oskb, &dst); + return pn_skb_send(sk, skb, &dst); +} + +static int pipe_snd_status(struct sock *sk, u8 type, u8 status, gfp_t priority) +{ + u8 data[4] = { type, PAD, PAD, status }; + + return pep_indicate(sk, PNS_PEP_STATUS_IND, PN_PEP_TYPE_COMMON, + data, 4, priority); +} + +/* Send our RX flow control information to the sender. + * Socket must be locked. */ +static void pipe_grant_credits(struct sock *sk, gfp_t priority) +{ + struct pep_sock *pn = pep_sk(sk); + + BUG_ON(sk->sk_state != TCP_ESTABLISHED); + + switch (pn->rx_fc) { + case PN_LEGACY_FLOW_CONTROL: /* TODO */ + break; + case PN_ONE_CREDIT_FLOW_CONTROL: + if (pipe_snd_status(sk, PN_PEP_IND_FLOW_CONTROL, + PEP_IND_READY, priority) == 0) + pn->rx_credits = 1; + break; + case PN_MULTI_CREDIT_FLOW_CONTROL: + if ((pn->rx_credits + CREDITS_THR) > CREDITS_MAX) + break; + if (pipe_snd_status(sk, PN_PEP_IND_ID_MCFC_GRANT_CREDITS, + CREDITS_MAX - pn->rx_credits, + priority) == 0) + pn->rx_credits = CREDITS_MAX; + break; + } +} + +static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb) +{ + struct pep_sock *pn = pep_sk(sk); + struct pnpipehdr *hdr; + int wake = 0; + + if (!pskb_may_pull(skb, sizeof(*hdr) + 4)) + return -EINVAL; + + hdr = pnp_hdr(skb); + if (hdr->pep_type != PN_PEP_TYPE_COMMON) { + net_dbg_ratelimited("Phonet unknown PEP type: %u\n", + (unsigned int)hdr->pep_type); + return -EOPNOTSUPP; + } + + switch (hdr->data[0]) { + case PN_PEP_IND_FLOW_CONTROL: + switch (pn->tx_fc) { + case PN_LEGACY_FLOW_CONTROL: + switch (hdr->data[3]) { + case PEP_IND_BUSY: + atomic_set(&pn->tx_credits, 0); + break; + case PEP_IND_READY: + atomic_set(&pn->tx_credits, wake = 1); + break; + } + break; + case PN_ONE_CREDIT_FLOW_CONTROL: + if (hdr->data[3] == PEP_IND_READY) + atomic_set(&pn->tx_credits, wake = 1); + break; + } + break; + + case PN_PEP_IND_ID_MCFC_GRANT_CREDITS: + if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL) + break; + atomic_add(wake = hdr->data[3], &pn->tx_credits); + break; + + default: + net_dbg_ratelimited("Phonet unknown PEP indication: %u\n", + (unsigned int)hdr->data[0]); + return -EOPNOTSUPP; + } + if (wake) + sk->sk_write_space(sk); + return 0; +} + +static int pipe_rcv_created(struct sock *sk, struct sk_buff *skb) +{ + struct pep_sock *pn = pep_sk(sk); + struct pnpipehdr *hdr = pnp_hdr(skb); + u8 n_sb = hdr->data0; + + pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL; + __skb_pull(skb, sizeof(*hdr)); + while (n_sb > 0) { + u8 type, buf[2], len = sizeof(buf); + u8 *data = pep_get_sb(skb, &type, &len, buf); + + if (data == NULL) + return -EINVAL; + switch (type) { + case PN_PIPE_SB_NEGOTIATED_FC: + if (len < 2 || (data[0] | data[1]) > 3) + break; + pn->tx_fc = data[0] & 3; + pn->rx_fc = data[1] & 3; + break; + } + n_sb--; + } + return 0; +} + +/* Queue an skb to a connected sock. + * Socket lock must be held. */ +static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb) +{ + struct pep_sock *pn = pep_sk(sk); + struct pnpipehdr *hdr = pnp_hdr(skb); + struct sk_buff_head *queue; + int err = 0; + + BUG_ON(sk->sk_state == TCP_CLOSE_WAIT); + + switch (hdr->message_id) { + case PNS_PEP_CONNECT_REQ: + pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, GFP_ATOMIC); + break; + + case PNS_PEP_DISCONNECT_REQ: + pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC); + sk->sk_state = TCP_CLOSE_WAIT; + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_state_change(sk); + break; + + case PNS_PEP_ENABLE_REQ: + /* Wait for PNS_PIPE_(ENABLED|REDIRECTED)_IND */ + pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC); + break; + + case PNS_PEP_RESET_REQ: + switch (hdr->state_after_reset) { + case PN_PIPE_DISABLE: + pn->init_enable = 0; + break; + case PN_PIPE_ENABLE: + pn->init_enable = 1; + break; + default: /* not allowed to send an error here!? */ + err = -EINVAL; + goto out; + } + fallthrough; + case PNS_PEP_DISABLE_REQ: + atomic_set(&pn->tx_credits, 0); + pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC); + break; + + case PNS_PEP_CTRL_REQ: + if (skb_queue_len(&pn->ctrlreq_queue) >= PNPIPE_CTRLREQ_MAX) { + atomic_inc(&sk->sk_drops); + break; + } + __skb_pull(skb, 4); + queue = &pn->ctrlreq_queue; + goto queue; + + case PNS_PIPE_ALIGNED_DATA: + __skb_pull(skb, 1); + fallthrough; + case PNS_PIPE_DATA: + __skb_pull(skb, 3); /* Pipe data header */ + if (!pn_flow_safe(pn->rx_fc)) { + err = sock_queue_rcv_skb(sk, skb); + if (!err) + return NET_RX_SUCCESS; + err = -ENOBUFS; + break; + } + + if (pn->rx_credits == 0) { + atomic_inc(&sk->sk_drops); + err = -ENOBUFS; + break; + } + pn->rx_credits--; + queue = &sk->sk_receive_queue; + goto queue; + + case PNS_PEP_STATUS_IND: + pipe_rcv_status(sk, skb); + break; + + case PNS_PIPE_REDIRECTED_IND: + err = pipe_rcv_created(sk, skb); + break; + + case PNS_PIPE_CREATED_IND: + err = pipe_rcv_created(sk, skb); + if (err) + break; + fallthrough; + case PNS_PIPE_RESET_IND: + if (!pn->init_enable) + break; + fallthrough; + case PNS_PIPE_ENABLED_IND: + if (!pn_flow_safe(pn->tx_fc)) { + atomic_set(&pn->tx_credits, 1); + sk->sk_write_space(sk); + } + if (sk->sk_state == TCP_ESTABLISHED) + break; /* Nothing to do */ + sk->sk_state = TCP_ESTABLISHED; + pipe_grant_credits(sk, GFP_ATOMIC); + break; + + case PNS_PIPE_DISABLED_IND: + sk->sk_state = TCP_SYN_RECV; + pn->rx_credits = 0; + break; + + default: + net_dbg_ratelimited("Phonet unknown PEP message: %u\n", + hdr->message_id); + err = -EINVAL; + } +out: + kfree_skb(skb); + return (err == -ENOBUFS) ? NET_RX_DROP : NET_RX_SUCCESS; + +queue: + skb->dev = NULL; + skb_set_owner_r(skb, sk); + skb_queue_tail(queue, skb); + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_data_ready(sk); + return NET_RX_SUCCESS; +} + +/* Destroy connected sock. */ +static void pipe_destruct(struct sock *sk) +{ + struct pep_sock *pn = pep_sk(sk); + + skb_queue_purge(&sk->sk_receive_queue); + skb_queue_purge(&pn->ctrlreq_queue); +} + +static u8 pipe_negotiate_fc(const u8 *fcs, unsigned int n) +{ + unsigned int i; + u8 final_fc = PN_NO_FLOW_CONTROL; + + for (i = 0; i < n; i++) { + u8 fc = fcs[i]; + + if (fc > final_fc && fc < PN_MAX_FLOW_CONTROL) + final_fc = fc; + } + return final_fc; +} + +static int pep_connresp_rcv(struct sock *sk, struct sk_buff *skb) +{ + struct pep_sock *pn = pep_sk(sk); + struct pnpipehdr *hdr; + u8 n_sb; + + if (!pskb_pull(skb, sizeof(*hdr) + 4)) + return -EINVAL; + + hdr = pnp_hdr(skb); + if (hdr->error_code != PN_PIPE_NO_ERROR) + return -ECONNREFUSED; + + /* Parse sub-blocks */ + n_sb = hdr->data[3]; + while (n_sb > 0) { + u8 type, buf[6], len = sizeof(buf); + const u8 *data = pep_get_sb(skb, &type, &len, buf); + + if (data == NULL) + return -EINVAL; + + switch (type) { + case PN_PIPE_SB_REQUIRED_FC_TX: + if (len < 2 || len < data[0]) + break; + pn->tx_fc = pipe_negotiate_fc(data + 2, len - 2); + break; + + case PN_PIPE_SB_PREFERRED_FC_RX: + if (len < 2 || len < data[0]) + break; + pn->rx_fc = pipe_negotiate_fc(data + 2, len - 2); + break; + + } + n_sb--; + } + + return pipe_handler_send_created_ind(sk); +} + +static int pep_enableresp_rcv(struct sock *sk, struct sk_buff *skb) +{ + struct pnpipehdr *hdr = pnp_hdr(skb); + + if (hdr->error_code != PN_PIPE_NO_ERROR) + return -ECONNREFUSED; + + return pep_indicate(sk, PNS_PIPE_ENABLED_IND, 0 /* sub-blocks */, + NULL, 0, GFP_ATOMIC); + +} + +static void pipe_start_flow_control(struct sock *sk) +{ + struct pep_sock *pn = pep_sk(sk); + + if (!pn_flow_safe(pn->tx_fc)) { + atomic_set(&pn->tx_credits, 1); + sk->sk_write_space(sk); + } + pipe_grant_credits(sk, GFP_ATOMIC); +} + +/* Queue an skb to an actively connected sock. + * Socket lock must be held. */ +static int pipe_handler_do_rcv(struct sock *sk, struct sk_buff *skb) +{ + struct pep_sock *pn = pep_sk(sk); + struct pnpipehdr *hdr = pnp_hdr(skb); + int err = NET_RX_SUCCESS; + + switch (hdr->message_id) { + case PNS_PIPE_ALIGNED_DATA: + __skb_pull(skb, 1); + fallthrough; + case PNS_PIPE_DATA: + __skb_pull(skb, 3); /* Pipe data header */ + if (!pn_flow_safe(pn->rx_fc)) { + err = sock_queue_rcv_skb(sk, skb); + if (!err) + return NET_RX_SUCCESS; + err = NET_RX_DROP; + break; + } + + if (pn->rx_credits == 0) { + atomic_inc(&sk->sk_drops); + err = NET_RX_DROP; + break; + } + pn->rx_credits--; + skb->dev = NULL; + skb_set_owner_r(skb, sk); + skb_queue_tail(&sk->sk_receive_queue, skb); + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_data_ready(sk); + return NET_RX_SUCCESS; + + case PNS_PEP_CONNECT_RESP: + if (sk->sk_state != TCP_SYN_SENT) + break; + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_state_change(sk); + if (pep_connresp_rcv(sk, skb)) { + sk->sk_state = TCP_CLOSE_WAIT; + break; + } + if (pn->init_enable == PN_PIPE_DISABLE) + sk->sk_state = TCP_SYN_RECV; + else { + sk->sk_state = TCP_ESTABLISHED; + pipe_start_flow_control(sk); + } + break; + + case PNS_PEP_ENABLE_RESP: + if (sk->sk_state != TCP_SYN_SENT) + break; + + if (pep_enableresp_rcv(sk, skb)) { + sk->sk_state = TCP_CLOSE_WAIT; + break; + } + + sk->sk_state = TCP_ESTABLISHED; + pipe_start_flow_control(sk); + break; + + case PNS_PEP_DISCONNECT_RESP: + /* sock should already be dead, nothing to do */ + break; + + case PNS_PEP_STATUS_IND: + pipe_rcv_status(sk, skb); + break; + } + kfree_skb(skb); + return err; +} + +/* Listening sock must be locked */ +static struct sock *pep_find_pipe(const struct hlist_head *hlist, + const struct sockaddr_pn *dst, + u8 pipe_handle) +{ + struct sock *sknode; + u16 dobj = pn_sockaddr_get_object(dst); + + sk_for_each(sknode, hlist) { + struct pep_sock *pnnode = pep_sk(sknode); + + /* Ports match, but addresses might not: */ + if (pnnode->pn_sk.sobject != dobj) + continue; + if (pnnode->pipe_handle != pipe_handle) + continue; + if (sknode->sk_state == TCP_CLOSE_WAIT) + continue; + + sock_hold(sknode); + return sknode; + } + return NULL; +} + +/* + * Deliver an skb to a listening sock. + * Socket lock must be held. + * We then queue the skb to the right connected sock (if any). + */ +static int pep_do_rcv(struct sock *sk, struct sk_buff *skb) +{ + struct pep_sock *pn = pep_sk(sk); + struct sock *sknode; + struct pnpipehdr *hdr; + struct sockaddr_pn dst; + u8 pipe_handle; + + if (!pskb_may_pull(skb, sizeof(*hdr))) + goto drop; + + hdr = pnp_hdr(skb); + pipe_handle = hdr->pipe_handle; + if (pipe_handle == PN_PIPE_INVALID_HANDLE) + goto drop; + + pn_skb_get_dst_sockaddr(skb, &dst); + + /* Look for an existing pipe handle */ + sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle); + if (sknode) + return sk_receive_skb(sknode, skb, 1); + + switch (hdr->message_id) { + case PNS_PEP_CONNECT_REQ: + if (sk->sk_state != TCP_LISTEN || sk_acceptq_is_full(sk)) { + pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, + GFP_ATOMIC); + break; + } + skb_queue_head(&sk->sk_receive_queue, skb); + sk_acceptq_added(sk); + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_data_ready(sk); + return NET_RX_SUCCESS; + + case PNS_PEP_DISCONNECT_REQ: + pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC); + break; + + case PNS_PEP_CTRL_REQ: + pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC); + break; + + case PNS_PEP_RESET_REQ: + case PNS_PEP_ENABLE_REQ: + case PNS_PEP_DISABLE_REQ: + /* invalid handle is not even allowed here! */ + break; + + default: + if ((1 << sk->sk_state) + & ~(TCPF_CLOSE|TCPF_LISTEN|TCPF_CLOSE_WAIT)) + /* actively connected socket */ + return pipe_handler_do_rcv(sk, skb); + } +drop: + kfree_skb(skb); + return NET_RX_SUCCESS; +} + +static int pipe_do_remove(struct sock *sk) +{ + struct pep_sock *pn = pep_sk(sk); + struct pnpipehdr *ph; + struct sk_buff *skb; + + skb = pep_alloc_skb(sk, NULL, 0, GFP_KERNEL); + if (!skb) + return -ENOMEM; + + ph = pnp_hdr(skb); + ph->utid = 0; + ph->message_id = PNS_PIPE_REMOVE_REQ; + ph->pipe_handle = pn->pipe_handle; + ph->data0 = PAD; + return pn_skb_send(sk, skb, NULL); +} + +/* associated socket ceases to exist */ +static void pep_sock_close(struct sock *sk, long timeout) +{ + struct pep_sock *pn = pep_sk(sk); + int ifindex = 0; + + sock_hold(sk); /* keep a reference after sk_common_release() */ + sk_common_release(sk); + + lock_sock(sk); + if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED)) { + if (sk->sk_backlog_rcv == pipe_do_rcv) + /* Forcefully remove dangling Phonet pipe */ + pipe_do_remove(sk); + else + pipe_handler_request(sk, PNS_PEP_DISCONNECT_REQ, PAD, + NULL, 0); + } + sk->sk_state = TCP_CLOSE; + + ifindex = pn->ifindex; + pn->ifindex = 0; + release_sock(sk); + + if (ifindex) + gprs_detach(sk); + sock_put(sk); +} + +static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp, + bool kern) +{ + struct pep_sock *pn = pep_sk(sk), *newpn; + struct sock *newsk = NULL; + struct sk_buff *skb; + struct pnpipehdr *hdr; + struct sockaddr_pn dst, src; + int err; + u16 peer_type; + u8 pipe_handle, enabled, n_sb; + u8 aligned = 0; + + skb = skb_recv_datagram(sk, 0, flags & O_NONBLOCK, errp); + if (!skb) + return NULL; + + lock_sock(sk); + if (sk->sk_state != TCP_LISTEN) { + err = -EINVAL; + goto drop; + } + sk_acceptq_removed(sk); + + err = -EPROTO; + if (!pskb_may_pull(skb, sizeof(*hdr) + 4)) + goto drop; + + hdr = pnp_hdr(skb); + pipe_handle = hdr->pipe_handle; + switch (hdr->state_after_connect) { + case PN_PIPE_DISABLE: + enabled = 0; + break; + case PN_PIPE_ENABLE: + enabled = 1; + break; + default: + pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM, + GFP_KERNEL); + goto drop; + } + peer_type = hdr->other_pep_type << 8; + + /* Parse sub-blocks (options) */ + n_sb = hdr->data[3]; + while (n_sb > 0) { + u8 type, buf[1], len = sizeof(buf); + const u8 *data = pep_get_sb(skb, &type, &len, buf); + + if (data == NULL) + goto drop; + switch (type) { + case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE: + if (len < 1) + goto drop; + peer_type = (peer_type & 0xff00) | data[0]; + break; + case PN_PIPE_SB_ALIGNED_DATA: + aligned = data[0] != 0; + break; + } + n_sb--; + } + + /* Check for duplicate pipe handle */ + newsk = pep_find_pipe(&pn->hlist, &dst, pipe_handle); + if (unlikely(newsk)) { + __sock_put(newsk); + newsk = NULL; + pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, GFP_KERNEL); + goto drop; + } + + /* Create a new to-be-accepted sock */ + newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_KERNEL, sk->sk_prot, + kern); + if (!newsk) { + pep_reject_conn(sk, skb, PN_PIPE_ERR_OVERLOAD, GFP_KERNEL); + err = -ENOBUFS; + goto drop; + } + + sock_init_data(NULL, newsk); + newsk->sk_state = TCP_SYN_RECV; + newsk->sk_backlog_rcv = pipe_do_rcv; + newsk->sk_protocol = sk->sk_protocol; + newsk->sk_destruct = pipe_destruct; + + newpn = pep_sk(newsk); + pn_skb_get_dst_sockaddr(skb, &dst); + pn_skb_get_src_sockaddr(skb, &src); + newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst); + newpn->pn_sk.dobject = pn_sockaddr_get_object(&src); + newpn->pn_sk.resource = pn_sockaddr_get_resource(&dst); + sock_hold(sk); + newpn->listener = sk; + skb_queue_head_init(&newpn->ctrlreq_queue); + newpn->pipe_handle = pipe_handle; + atomic_set(&newpn->tx_credits, 0); + newpn->ifindex = 0; + newpn->peer_type = peer_type; + newpn->rx_credits = 0; + newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL; + newpn->init_enable = enabled; + newpn->aligned = aligned; + + err = pep_accept_conn(newsk, skb); + if (err) { + __sock_put(sk); + sock_put(newsk); + newsk = NULL; + goto drop; + } + sk_add_node(newsk, &pn->hlist); +drop: + release_sock(sk); + kfree_skb(skb); + *errp = err; + return newsk; +} + +static int pep_sock_connect(struct sock *sk, struct sockaddr *addr, int len) +{ + struct pep_sock *pn = pep_sk(sk); + int err; + u8 data[4] = { 0 /* sub-blocks */, PAD, PAD, PAD }; + + if (pn->pipe_handle == PN_PIPE_INVALID_HANDLE) + pn->pipe_handle = 1; /* anything but INVALID_HANDLE */ + + err = pipe_handler_request(sk, PNS_PEP_CONNECT_REQ, + pn->init_enable, data, 4); + if (err) { + pn->pipe_handle = PN_PIPE_INVALID_HANDLE; + return err; + } + + sk->sk_state = TCP_SYN_SENT; + + return 0; +} + +static int pep_sock_enable(struct sock *sk, struct sockaddr *addr, int len) +{ + int err; + + err = pipe_handler_request(sk, PNS_PEP_ENABLE_REQ, PAD, + NULL, 0); + if (err) + return err; + + sk->sk_state = TCP_SYN_SENT; + + return 0; +} + +static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg) +{ + struct pep_sock *pn = pep_sk(sk); + int answ; + int ret = -ENOIOCTLCMD; + + switch (cmd) { + case SIOCINQ: + if (sk->sk_state == TCP_LISTEN) { + ret = -EINVAL; + break; + } + + lock_sock(sk); + if (sock_flag(sk, SOCK_URGINLINE) && + !skb_queue_empty(&pn->ctrlreq_queue)) + answ = skb_peek(&pn->ctrlreq_queue)->len; + else if (!skb_queue_empty(&sk->sk_receive_queue)) + answ = skb_peek(&sk->sk_receive_queue)->len; + else + answ = 0; + release_sock(sk); + ret = put_user(answ, (int __user *)arg); + break; + + case SIOCPNENABLEPIPE: + lock_sock(sk); + if (sk->sk_state == TCP_SYN_SENT) + ret = -EBUSY; + else if (sk->sk_state == TCP_ESTABLISHED) + ret = -EISCONN; + else if (!pn->pn_sk.sobject) + ret = -EADDRNOTAVAIL; + else + ret = pep_sock_enable(sk, NULL, 0); + release_sock(sk); + break; + } + + return ret; +} + +static int pep_init(struct sock *sk) +{ + struct pep_sock *pn = pep_sk(sk); + + sk->sk_destruct = pipe_destruct; + INIT_HLIST_HEAD(&pn->hlist); + pn->listener = NULL; + skb_queue_head_init(&pn->ctrlreq_queue); + atomic_set(&pn->tx_credits, 0); + pn->ifindex = 0; + pn->peer_type = 0; + pn->pipe_handle = PN_PIPE_INVALID_HANDLE; + pn->rx_credits = 0; + pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL; + pn->init_enable = 1; + pn->aligned = 0; + return 0; +} + +static int pep_setsockopt(struct sock *sk, int level, int optname, + sockptr_t optval, unsigned int optlen) +{ + struct pep_sock *pn = pep_sk(sk); + int val = 0, err = 0; + + if (level != SOL_PNPIPE) + return -ENOPROTOOPT; + if (optlen >= sizeof(int)) { + if (copy_from_sockptr(&val, optval, sizeof(int))) + return -EFAULT; + } + + lock_sock(sk); + switch (optname) { + case PNPIPE_ENCAP: + if (val && val != PNPIPE_ENCAP_IP) { + err = -EINVAL; + break; + } + if (!pn->ifindex == !val) + break; /* Nothing to do! */ + if (!capable(CAP_NET_ADMIN)) { + err = -EPERM; + break; + } + if (val) { + release_sock(sk); + err = gprs_attach(sk); + if (err > 0) { + pn->ifindex = err; + err = 0; + } + } else { + pn->ifindex = 0; + release_sock(sk); + gprs_detach(sk); + err = 0; + } + goto out_norel; + + case PNPIPE_HANDLE: + if ((sk->sk_state == TCP_CLOSE) && + (val >= 0) && (val < PN_PIPE_INVALID_HANDLE)) + pn->pipe_handle = val; + else + err = -EINVAL; + break; + + case PNPIPE_INITSTATE: + pn->init_enable = !!val; + break; + + default: + err = -ENOPROTOOPT; + } + release_sock(sk); + +out_norel: + return err; +} + +static int pep_getsockopt(struct sock *sk, int level, int optname, + char __user *optval, int __user *optlen) +{ + struct pep_sock *pn = pep_sk(sk); + int len, val; + + if (level != SOL_PNPIPE) + return -ENOPROTOOPT; + if (get_user(len, optlen)) + return -EFAULT; + + switch (optname) { + case PNPIPE_ENCAP: + val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE; + break; + + case PNPIPE_IFINDEX: + val = pn->ifindex; + break; + + case PNPIPE_HANDLE: + val = pn->pipe_handle; + if (val == PN_PIPE_INVALID_HANDLE) + return -EINVAL; + break; + + case PNPIPE_INITSTATE: + val = pn->init_enable; + break; + + default: + return -ENOPROTOOPT; + } + + len = min_t(unsigned int, sizeof(int), len); + if (put_user(len, optlen)) + return -EFAULT; + if (put_user(val, (int __user *) optval)) + return -EFAULT; + return 0; +} + +static int pipe_skb_send(struct sock *sk, struct sk_buff *skb) +{ + struct pep_sock *pn = pep_sk(sk); + struct pnpipehdr *ph; + int err; + + if (pn_flow_safe(pn->tx_fc) && + !atomic_add_unless(&pn->tx_credits, -1, 0)) { + kfree_skb(skb); + return -ENOBUFS; + } + + skb_push(skb, 3 + pn->aligned); + skb_reset_transport_header(skb); + ph = pnp_hdr(skb); + ph->utid = 0; + if (pn->aligned) { + ph->message_id = PNS_PIPE_ALIGNED_DATA; + ph->data0 = 0; /* padding */ + } else + ph->message_id = PNS_PIPE_DATA; + ph->pipe_handle = pn->pipe_handle; + err = pn_skb_send(sk, skb, NULL); + + if (err && pn_flow_safe(pn->tx_fc)) + atomic_inc(&pn->tx_credits); + return err; + +} + +static int pep_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) +{ + struct pep_sock *pn = pep_sk(sk); + struct sk_buff *skb; + long timeo; + int flags = msg->msg_flags; + int err, done; + + if (len > USHRT_MAX) + return -EMSGSIZE; + + if ((msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL| + MSG_CMSG_COMPAT)) || + !(msg->msg_flags & MSG_EOR)) + return -EOPNOTSUPP; + + skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len, + flags & MSG_DONTWAIT, &err); + if (!skb) + return err; + + skb_reserve(skb, MAX_PHONET_HEADER + 3 + pn->aligned); + err = memcpy_from_msg(skb_put(skb, len), msg, len); + if (err < 0) + goto outfree; + + lock_sock(sk); + timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); + if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) { + err = -ENOTCONN; + goto out; + } + if (sk->sk_state != TCP_ESTABLISHED) { + /* Wait until the pipe gets to enabled state */ +disabled: + err = sk_stream_wait_connect(sk, &timeo); + if (err) + goto out; + + if (sk->sk_state == TCP_CLOSE_WAIT) { + err = -ECONNRESET; + goto out; + } + } + BUG_ON(sk->sk_state != TCP_ESTABLISHED); + + /* Wait until flow control allows TX */ + done = atomic_read(&pn->tx_credits); + while (!done) { + DEFINE_WAIT_FUNC(wait, woken_wake_function); + + if (!timeo) { + err = -EAGAIN; + goto out; + } + if (signal_pending(current)) { + err = sock_intr_errno(timeo); + goto out; + } + + add_wait_queue(sk_sleep(sk), &wait); + done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits), &wait); + remove_wait_queue(sk_sleep(sk), &wait); + + if (sk->sk_state != TCP_ESTABLISHED) + goto disabled; + } + + err = pipe_skb_send(sk, skb); + if (err >= 0) + err = len; /* success! */ + skb = NULL; +out: + release_sock(sk); +outfree: + kfree_skb(skb); + return err; +} + +int pep_writeable(struct sock *sk) +{ + struct pep_sock *pn = pep_sk(sk); + + return atomic_read(&pn->tx_credits); +} + +int pep_write(struct sock *sk, struct sk_buff *skb) +{ + struct sk_buff *rskb, *fs; + int flen = 0; + + if (pep_sk(sk)->aligned) + return pipe_skb_send(sk, skb); + + rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC); + if (!rskb) { + kfree_skb(skb); + return -ENOMEM; + } + skb_shinfo(rskb)->frag_list = skb; + rskb->len += skb->len; + rskb->data_len += rskb->len; + rskb->truesize += rskb->len; + + /* Avoid nested fragments */ + skb_walk_frags(skb, fs) + flen += fs->len; + skb->next = skb_shinfo(skb)->frag_list; + skb_frag_list_init(skb); + skb->len -= flen; + skb->data_len -= flen; + skb->truesize -= flen; + + skb_reserve(rskb, MAX_PHONET_HEADER + 3); + return pipe_skb_send(sk, rskb); +} + +struct sk_buff *pep_read(struct sock *sk) +{ + struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue); + + if (sk->sk_state == TCP_ESTABLISHED) + pipe_grant_credits(sk, GFP_ATOMIC); + return skb; +} + +static int pep_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, + int noblock, int flags, int *addr_len) +{ + struct sk_buff *skb; + int err; + + if (flags & ~(MSG_OOB|MSG_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_WAITALL| + MSG_NOSIGNAL|MSG_CMSG_COMPAT)) + return -EOPNOTSUPP; + + if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE))) + return -ENOTCONN; + + if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) { + /* Dequeue and acknowledge control request */ + struct pep_sock *pn = pep_sk(sk); + + if (flags & MSG_PEEK) + return -EOPNOTSUPP; + skb = skb_dequeue(&pn->ctrlreq_queue); + if (skb) { + pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR, + GFP_KERNEL); + msg->msg_flags |= MSG_OOB; + goto copy; + } + if (flags & MSG_OOB) + return -EINVAL; + } + + skb = skb_recv_datagram(sk, flags, noblock, &err); + lock_sock(sk); + if (skb == NULL) { + if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT) + err = -ECONNRESET; + release_sock(sk); + return err; + } + + if (sk->sk_state == TCP_ESTABLISHED) + pipe_grant_credits(sk, GFP_KERNEL); + release_sock(sk); +copy: + msg->msg_flags |= MSG_EOR; + if (skb->len > len) + msg->msg_flags |= MSG_TRUNC; + else + len = skb->len; + + err = skb_copy_datagram_msg(skb, 0, msg, len); + if (!err) + err = (flags & MSG_TRUNC) ? skb->len : len; + + skb_free_datagram(sk, skb); + return err; +} + +static void pep_sock_unhash(struct sock *sk) +{ + struct pep_sock *pn = pep_sk(sk); + struct sock *skparent = NULL; + + lock_sock(sk); + + if (pn->listener != NULL) { + skparent = pn->listener; + pn->listener = NULL; + release_sock(sk); + + pn = pep_sk(skparent); + lock_sock(skparent); + sk_del_node_init(sk); + sk = skparent; + } + + /* Unhash a listening sock only when it is closed + * and all of its active connected pipes are closed. */ + if (hlist_empty(&pn->hlist)) + pn_sock_unhash(&pn->pn_sk.sk); + release_sock(sk); + + if (skparent) + sock_put(skparent); +} + +static struct proto pep_proto = { + .close = pep_sock_close, + .accept = pep_sock_accept, + .connect = pep_sock_connect, + .ioctl = pep_ioctl, + .init = pep_init, + .setsockopt = pep_setsockopt, + .getsockopt = pep_getsockopt, + .sendmsg = pep_sendmsg, + .recvmsg = pep_recvmsg, + .backlog_rcv = pep_do_rcv, + .hash = pn_sock_hash, + .unhash = pep_sock_unhash, + .get_port = pn_sock_get_port, + .obj_size = sizeof(struct pep_sock), + .owner = THIS_MODULE, + .name = "PNPIPE", +}; + +static const struct phonet_protocol pep_pn_proto = { + .ops = &phonet_stream_ops, + .prot = &pep_proto, + .sock_type = SOCK_SEQPACKET, +}; + +static int __init pep_register(void) +{ + return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto); +} + +static void __exit pep_unregister(void) +{ + phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto); +} + +module_init(pep_register); +module_exit(pep_unregister); +MODULE_AUTHOR("Remi Denis-Courmont, Nokia"); +MODULE_DESCRIPTION("Phonet pipe protocol"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE); |