static int raw_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, size_t len, int noblock, int flags, int *addr_len) { struct inet_sock *inet = inet_sk(sk); size_t copied = 0; int err = -EOPNOTSUPP; struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; struct sk_buff *skb; if (flags & MSG_OOB) goto out; if (addr_len) *addr_len = sizeof(*sin); if (flags & MSG_ERRQUEUE) { err = ip_recv_error(sk, msg, len); goto out; } skb = skb_recv_datagram(sk, flags, noblock, &err); if (!skb) goto out; copied = skb->len; if (len < copied) { msg->msg_flags |= MSG_TRUNC; copied = len; } err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); if (err) goto done; sock_recv_timestamp(msg, sk, skb); /* Copy the address. */ if (sin) { sin->sin_family = AF_INET; sin->sin_addr.s_addr = ip_hdr(skb)->saddr; sin->sin_port = 0; memset(&sin->sin_zero, 0, sizeof(sin->sin_zero)); } if (inet->cmsg_flags) ip_cmsg_recv(msg, skb); if (flags & MSG_TRUNC) copied = skb->len; done: skb_free_datagram(sk, skb); out: if (err) return err; return copied; }
/* * Handle MSG_ERRQUEUE */ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len) { struct ipv6_pinfo *np = inet6_sk(sk); struct sock_exterr_skb *serr; struct sk_buff *skb, *skb2; struct sockaddr_in6 *sin; struct { struct sock_extended_err ee; struct sockaddr_in6 offender; } errhdr; int err; int copied; err = -EAGAIN; skb = skb_dequeue(&sk->sk_error_queue); if (skb == NULL) goto out; copied = skb->len; if (copied > len) { msg->msg_flags |= MSG_TRUNC; copied = len; } err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); if (err) goto out_free_skb; sock_recv_timestamp(msg, sk, skb); serr = SKB_EXT_ERR(skb); sin = (struct sockaddr_in6 *)msg->msg_name; if (sin) { const unsigned char *nh = skb_network_header(skb); sin->sin6_family = AF_INET6; sin->sin6_flowinfo = 0; sin->sin6_port = serr->port; if (skb->protocol == htons(ETH_P_IPV6)) { const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset), struct ipv6hdr, daddr); sin->sin6_addr = ip6h->daddr; if (np->sndflow) sin->sin6_flowinfo = ip6_flowinfo(ip6h); sin->sin6_scope_id = ipv6_iface_scope_id(&sin->sin6_addr, IP6CB(skb)->iif); } else { ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset), &sin->sin6_addr); sin->sin6_scope_id = 0; } *addr_len = sizeof(*sin); }
/* * Handle IPV6_RECVPATHMTU */ int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len, int *addr_len) { struct ipv6_pinfo *np = inet6_sk(sk); struct sk_buff *skb; struct sockaddr_in6 *sin; struct ip6_mtuinfo mtu_info; int err; int copied; err = -EAGAIN; skb = xchg(&np->rxpmtu, NULL); if (skb == NULL) goto out; copied = skb->len; if (copied > len) { msg->msg_flags |= MSG_TRUNC; copied = len; } err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); if (err) goto out_free_skb; sock_recv_timestamp(msg, sk, skb); memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info)); sin = (struct sockaddr_in6 *)msg->msg_name; if (sin) { sin->sin6_family = AF_INET6; sin->sin6_flowinfo = 0; sin->sin6_port = 0; sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id; ipv6_addr_copy(&sin->sin6_addr, &mtu_info.ip6m_addr.sin6_addr); *addr_len = sizeof(*sin); } put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info); err = copied; out_free_skb: kfree_skb(skb); out: return err; }
static int raw_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, size_t size, int flags) { struct sock *sk = sock->sk; struct sk_buff *skb; int error = 0; int noblock; DBG("socket %p, sk %p\n", sock, sk); noblock = flags & MSG_DONTWAIT; flags &= ~MSG_DONTWAIT; skb = skb_recv_datagram(sk, flags, noblock, &error); if (!skb) return error; DBG("delivering skbuff %p\n", skb); DBG_SKB(skb); if (size < skb->len) msg->msg_flags |= MSG_TRUNC; else size = skb->len; error = memcpy_toiovec(msg->msg_iov, skb->data, size); if (error < 0) { skb_free_datagram(sk, skb); return error; } sock_recv_timestamp(msg, sk, skb); if (msg->msg_name) { msg->msg_namelen = sizeof(struct sockaddr_can); memcpy(msg->msg_name, skb->cb, msg->msg_namelen); } DBG("freeing sock %p, skbuff %p\n", sk, skb); skb_free_datagram(sk, skb); return size; }
static int raw_recvmsg(struct socket *sock, struct msghdr *msg, int size, int flags, struct scm_cookie *scm) { struct sock *sk = sock->sk; struct sk_buff *skb; int err = 0; int noblock; noblock = flags & MSG_DONTWAIT; flags &= ~MSG_DONTWAIT; skb = skb_recv_datagram(sk, flags, noblock, &err); if (!skb) return err; if (size < skb->len) msg->msg_flags |= MSG_TRUNC; else size = skb->len; err = memcpy_toiovec(msg->msg_iov, skb->data, size); if (err < 0) { skb_free_datagram(sk, skb); return err; } sock_recv_timestamp(msg, sk, skb); if (msg->msg_name) { msg->msg_namelen = sizeof(struct sockaddr_can); memcpy(msg->msg_name, skb->cb, msg->msg_namelen); } skb_free_datagram(sk, skb); return size; }
/* * Handle MSG_ERRQUEUE */ int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len) { struct sock_exterr_skb *serr; struct sk_buff *skb; DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); struct { struct sock_extended_err ee; struct sockaddr_in offender; } errhdr; int err; int copied; WARN_ON_ONCE(sk->sk_family == AF_INET6); err = -EAGAIN; skb = sock_dequeue_err_skb(sk); if (!skb) goto out; copied = skb->len; if (copied > len) { msg->msg_flags |= MSG_TRUNC; copied = len; } err = skb_copy_datagram_msg(skb, 0, msg, copied); if (unlikely(err)) { kfree_skb(skb); return err; } sock_recv_timestamp(msg, sk, skb); serr = SKB_EXT_ERR(skb); if (sin && ipv4_datagram_support_addr(serr)) { sin->sin_family = AF_INET; sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) + serr->addr_offset); sin->sin_port = serr->port; memset(&sin->sin_zero, 0, sizeof(sin->sin_zero)); *addr_len = sizeof(*sin); } memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err)); sin = &errhdr.offender; memset(sin, 0, sizeof(*sin)); if (ipv4_datagram_support_cmsg(sk, skb, serr->ee.ee_origin)) { sin->sin_family = AF_INET; sin->sin_addr.s_addr = ip_hdr(skb)->saddr; if (inet_sk(sk)->cmsg_flags) ip_cmsg_recv(msg, skb); } put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr); /* Now we could try to dump offended packet options */ msg->msg_flags |= MSG_ERRQUEUE; err = copied; consume_skb(skb); out: return err; }
static int packet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, size_t len, int flags) { struct sock *sk = sock->sk; struct sk_buff *skb; int copied, err; err = -EINVAL; if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT)) goto out; #if 0 /* What error should we return now? EUNATTACH? */ if (pkt_sk(sk)->ifindex < 0) return -ENODEV; #endif /* * If the address length field is there to be filled in, we fill * it in now. */ if (sock->type == SOCK_PACKET) msg->msg_namelen = sizeof(struct sockaddr_pkt); else msg->msg_namelen = sizeof(struct sockaddr_ll); /* * Call the generic datagram receiver. This handles all sorts * of horrible races and re-entrancy so we can forget about it * in the protocol layers. * * Now it will return ENETDOWN, if device have just gone down, * but then it will block. */ skb=skb_recv_datagram(sk,flags,flags&MSG_DONTWAIT,&err); /* * An error occurred so return it. Because skb_recv_datagram() * handles the blocking we don't see and worry about blocking * retries. */ if(skb==NULL) goto out; /* * You lose any data beyond the buffer you gave. If it worries a * user program they can ask the device for its MTU anyway. */ copied = skb->len; if (copied > len) { copied=len; msg->msg_flags|=MSG_TRUNC; } err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); if (err) goto out_free; sock_recv_timestamp(msg, sk, skb); if (msg->msg_name) memcpy(msg->msg_name, skb->cb, msg->msg_namelen); /* * Free or return the buffer as appropriate. Again this * hides all the races and re-entrancy issues from us. */ err = (flags&MSG_TRUNC) ? skb->len : copied; out_free: skb_free_datagram(sk, skb); out: return err; }
int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, int len, int noblock, int flags, int *addr_len) { struct sk_buff *skb; int copied, err; if (addr_len) *addr_len=sizeof(struct sockaddr_in6); if (flags & MSG_ERRQUEUE) return ipv6_recv_error(sk, msg, len); skb = skb_recv_datagram(sk, flags, noblock, &err); if (!skb) goto out; copied = skb->len - sizeof(struct udphdr); if (copied > len) { copied = len; msg->msg_flags |= MSG_TRUNC; } if (skb->ip_summed==CHECKSUM_UNNECESSARY) { err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov, copied); } else if (msg->msg_flags&MSG_TRUNC) { if ((unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum))) goto csum_copy_err; err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov, copied); } else { err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov); if (err == -EINVAL) goto csum_copy_err; } if (err) goto out_free; sock_recv_timestamp(msg, sk, skb); /* Copy the address. */ if (msg->msg_name) { struct sockaddr_in6 *sin6; sin6 = (struct sockaddr_in6 *) msg->msg_name; sin6->sin6_family = AF_INET6; sin6->sin6_port = skb->h.uh->source; sin6->sin6_flowinfo = 0; sin6->sin6_scope_id = 0; if (skb->protocol == __constant_htons(ETH_P_IP)) { ipv6_addr_set(&sin6->sin6_addr, 0, 0, __constant_htonl(0xffff), skb->nh.iph->saddr); if (sk->protinfo.af_inet.cmsg_flags) ip_cmsg_recv(msg, skb); } else { memcpy(&sin6->sin6_addr, &skb->nh.ipv6h->saddr, sizeof(struct in6_addr)); if (sk->net_pinfo.af_inet6.rxopt.all) datagram_recv_ctl(sk, msg, skb); if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) { struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb; sin6->sin6_scope_id = opt->iif; } } } err = copied; out_free: skb_free_datagram(sk, skb); out: return err; csum_copy_err: /* Clear queue. */ if (flags&MSG_PEEK) { int clear = 0; spin_lock_irq(&sk->receive_queue.lock); if (skb == skb_peek(&sk->receive_queue)) { __skb_unlink(skb, &sk->receive_queue); clear = 1; } spin_unlock_irq(&sk->receive_queue.lock); if (clear) kfree_skb(skb); } /* Error for blocking case is chosen to masquerade as some normal condition. */ err = (flags&MSG_DONTWAIT) ? -EAGAIN : -EHOSTUNREACH; UDP6_INC_STATS_USER(UdpInErrors); goto out_free; }
/* * Handle MSG_ERRQUEUE */ int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len) { struct sock_exterr_skb *serr; struct sk_buff *skb, *skb2; struct sockaddr_in *sin; struct { struct sock_extended_err ee; struct sockaddr_in offender; } errhdr; int err; int copied; err = -EAGAIN; skb = skb_dequeue(&sk->sk_error_queue); if (skb == NULL) goto out; copied = skb->len; if (copied > len) { msg->msg_flags |= MSG_TRUNC; copied = len; } err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); if (err) goto out_free_skb; sock_recv_timestamp(msg, sk, skb); serr = SKB_EXT_ERR(skb); sin = (struct sockaddr_in *)msg->msg_name; if (sin) { sin->sin_family = AF_INET; sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) + serr->addr_offset); sin->sin_port = serr->port; memset(&sin->sin_zero, 0, sizeof(sin->sin_zero)); *addr_len = sizeof(*sin); } memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err)); sin = &errhdr.offender; sin->sin_family = AF_UNSPEC; if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP) { struct inet_sock *inet = inet_sk(sk); sin->sin_family = AF_INET; sin->sin_addr.s_addr = ip_hdr(skb)->saddr; sin->sin_port = 0; memset(&sin->sin_zero, 0, sizeof(sin->sin_zero)); if (inet->cmsg_flags) ip_cmsg_recv(msg, skb); } put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr); /* Now we could try to dump offended packet options */ msg->msg_flags |= MSG_ERRQUEUE; err = copied; /* Reset and regenerate socket error */ spin_lock_bh(&sk->sk_error_queue.lock); sk->sk_err = 0; skb2 = skb_peek(&sk->sk_error_queue); if (skb2 != NULL) { sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno; spin_unlock_bh(&sk->sk_error_queue.lock); sk->sk_error_report(sk); } else spin_unlock_bh(&sk->sk_error_queue.lock); out_free_skb: kfree_skb(skb); out: return err; }
/* * receive a message from an RxRPC socket * - we need to be careful about two or more threads calling recvmsg * simultaneously */ int rxrpc_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, size_t len, int flags) { struct rxrpc_skb_priv *sp; struct rxrpc_call *call = NULL, *continue_call = NULL; struct rxrpc_sock *rx = rxrpc_sk(sock->sk); struct sk_buff *skb; long timeo; int copy, ret, ullen, offset, copied = 0; u32 abort_code; DEFINE_WAIT(wait); _enter(",,,%zu,%d", len, flags); if (flags & (MSG_OOB | MSG_TRUNC)) return -EOPNOTSUPP; ullen = msg->msg_flags & MSG_CMSG_COMPAT ? 4 : sizeof(unsigned long); timeo = sock_rcvtimeo(&rx->sk, flags & MSG_DONTWAIT); msg->msg_flags |= MSG_MORE; lock_sock(&rx->sk); for (;;) { /* return immediately if a client socket has no outstanding * calls */ if (RB_EMPTY_ROOT(&rx->calls)) { if (copied) goto out; if (rx->sk.sk_state != RXRPC_SERVER_LISTENING) { release_sock(&rx->sk); if (continue_call) rxrpc_put_call(continue_call); return -ENODATA; } } /* get the next message on the Rx queue */ skb = skb_peek(&rx->sk.sk_receive_queue); if (!skb) { /* nothing remains on the queue */ if (copied && (msg->msg_flags & MSG_PEEK || timeo == 0)) goto out; /* wait for a message to turn up */ release_sock(&rx->sk); prepare_to_wait_exclusive(rx->sk.sk_sleep, &wait, TASK_INTERRUPTIBLE); ret = sock_error(&rx->sk); if (ret) goto wait_error; if (skb_queue_empty(&rx->sk.sk_receive_queue)) { if (signal_pending(current)) goto wait_interrupted; timeo = schedule_timeout(timeo); } finish_wait(rx->sk.sk_sleep, &wait); lock_sock(&rx->sk); continue; } peek_next_packet: sp = rxrpc_skb(skb); call = sp->call; ASSERT(call != NULL); _debug("next pkt %s", rxrpc_pkts[sp->hdr.type]); /* make sure we wait for the state to be updated in this call */ spin_lock_bh(&call->lock); spin_unlock_bh(&call->lock); if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) { _debug("packet from released call"); if (skb_dequeue(&rx->sk.sk_receive_queue) != skb) BUG(); rxrpc_free_skb(skb); continue; } /* determine whether to continue last data receive */ if (continue_call) { _debug("maybe cont"); if (call != continue_call || skb->mark != RXRPC_SKB_MARK_DATA) { release_sock(&rx->sk); rxrpc_put_call(continue_call); _leave(" = %d [noncont]", copied); return copied; } } rxrpc_get_call(call); /* copy the peer address and timestamp */ if (!continue_call) { if (msg->msg_name && msg->msg_namelen > 0) memcpy(msg->msg_name, &call->conn->trans->peer->srx, sizeof(call->conn->trans->peer->srx)); sock_recv_timestamp(msg, &rx->sk, skb); } /* receive the message */ if (skb->mark != RXRPC_SKB_MARK_DATA) goto receive_non_data_message; _debug("recvmsg DATA #%u { %d, %d }", ntohl(sp->hdr.seq), skb->len, sp->offset); if (!continue_call) { /* only set the control data once per recvmsg() */ ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID, ullen, &call->user_call_ID); if (ret < 0) goto copy_error; ASSERT(test_bit(RXRPC_CALL_HAS_USERID, &call->flags)); } ASSERTCMP(ntohl(sp->hdr.seq), >=, call->rx_data_recv); ASSERTCMP(ntohl(sp->hdr.seq), <=, call->rx_data_recv + 1); call->rx_data_recv = ntohl(sp->hdr.seq); ASSERTCMP(ntohl(sp->hdr.seq), >, call->rx_data_eaten); offset = sp->offset; copy = skb->len - offset; if (copy > len - copied) copy = len - copied; if (skb->ip_summed == CHECKSUM_UNNECESSARY) { ret = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copy); } else { ret = skb_copy_and_csum_datagram_iovec(skb, offset, msg->msg_iov); if (ret == -EINVAL) goto csum_copy_error; } if (ret < 0) goto copy_error; /* handle piecemeal consumption of data packets */ _debug("copied %d+%d", copy, copied); offset += copy; copied += copy; if (!(flags & MSG_PEEK)) sp->offset = offset; if (sp->offset < skb->len) { _debug("buffer full"); ASSERTCMP(copied, ==, len); break; } /* we transferred the whole data packet */ if (sp->hdr.flags & RXRPC_LAST_PACKET) { _debug("last"); if (call->conn->out_clientflag) { /* last byte of reply received */ ret = copied; goto terminal_message; } /* last bit of request received */ if (!(flags & MSG_PEEK)) { _debug("eat packet"); if (skb_dequeue(&rx->sk.sk_receive_queue) != skb) BUG(); rxrpc_free_skb(skb); } msg->msg_flags &= ~MSG_MORE; break; } /* move on to the next data message */ _debug("next"); if (!continue_call) continue_call = sp->call; else rxrpc_put_call(call); call = NULL; if (flags & MSG_PEEK) { _debug("peek next"); skb = skb->next; if (skb == (struct sk_buff *) &rx->sk.sk_receive_queue) break; goto peek_next_packet; } _debug("eat packet"); if (skb_dequeue(&rx->sk.sk_receive_queue) != skb) BUG(); rxrpc_free_skb(skb); }
/* * Handle MSG_ERRQUEUE */ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len) { struct ipv6_pinfo *np = inet6_sk(sk); struct sock_exterr_skb *serr; struct sk_buff *skb, *skb2; struct sockaddr_in6 *sin; struct { struct sock_extended_err ee; struct sockaddr_in6 offender; } errhdr; int err; int copied; err = -EAGAIN; skb = skb_dequeue(&sk->sk_error_queue); if (skb == NULL) goto out; copied = skb->len; if (copied > len) { msg->msg_flags |= MSG_TRUNC; copied = len; } err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); if (err) goto out_free_skb; sock_recv_timestamp(msg, sk, skb); serr = SKB_EXT_ERR(skb); sin = (struct sockaddr_in6 *)msg->msg_name; if (sin) { const unsigned char *nh = skb_network_header(skb); sin->sin6_family = AF_INET6; sin->sin6_flowinfo = 0; sin->sin6_port = serr->port; sin->sin6_scope_id = 0; if (skb->protocol == htons(ETH_P_IPV6)) { ipv6_addr_copy(&sin->sin6_addr, (struct in6_addr *)(nh + serr->addr_offset)); if (np->sndflow) sin->sin6_flowinfo = (*(__be32 *)(nh + serr->addr_offset - 24) & IPV6_FLOWINFO_MASK); if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL) sin->sin6_scope_id = IP6CB(skb)->iif; } else { ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset), &sin->sin6_addr); } } memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err)); sin = &errhdr.offender; sin->sin6_family = AF_UNSPEC; if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) { sin->sin6_family = AF_INET6; sin->sin6_flowinfo = 0; sin->sin6_scope_id = 0; if (skb->protocol == htons(ETH_P_IPV6)) { ipv6_addr_copy(&sin->sin6_addr, &ipv6_hdr(skb)->saddr); if (np->rxopt.all) datagram_recv_ctl(sk, msg, skb); if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL) sin->sin6_scope_id = IP6CB(skb)->iif; } else { struct inet_sock *inet = inet_sk(sk); ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &sin->sin6_addr); if (inet->cmsg_flags) ip_cmsg_recv(msg, skb); } } put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr); /* Now we could try to dump offended packet options */ msg->msg_flags |= MSG_ERRQUEUE; err = copied; /* Reset and regenerate socket error */ spin_lock_bh(&sk->sk_error_queue.lock); sk->sk_err = 0; if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) { sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno; spin_unlock_bh(&sk->sk_error_queue.lock); sk->sk_error_report(sk); } else { spin_unlock_bh(&sk->sk_error_queue.lock); } out_free_skb: kfree_skb(skb); out: return err; }
/* * Deliver messages to a call. This keeps processing packets until the buffer * is filled and we find either more DATA (returns 0) or the end of the DATA * (returns 1). If more packets are required, it returns -EAGAIN. */ static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call, struct msghdr *msg, struct iov_iter *iter, size_t len, int flags, size_t *_offset) { struct rxrpc_skb_priv *sp; struct sk_buff *skb; rxrpc_seq_t hard_ack, top, seq; size_t remain; bool last; unsigned int rx_pkt_offset, rx_pkt_len; int ix, copy, ret = -EAGAIN, ret2; rx_pkt_offset = call->rx_pkt_offset; rx_pkt_len = call->rx_pkt_len; if (call->state >= RXRPC_CALL_SERVER_ACK_REQUEST) { seq = call->rx_hard_ack; ret = 1; goto done; } /* Barriers against rxrpc_input_data(). */ hard_ack = call->rx_hard_ack; top = smp_load_acquire(&call->rx_top); for (seq = hard_ack + 1; before_eq(seq, top); seq++) { ix = seq & RXRPC_RXTX_BUFF_MASK; skb = call->rxtx_buffer[ix]; if (!skb) { trace_rxrpc_recvmsg(call, rxrpc_recvmsg_hole, seq, rx_pkt_offset, rx_pkt_len, 0); break; } smp_rmb(); rxrpc_see_skb(skb, rxrpc_skb_rx_seen); sp = rxrpc_skb(skb); if (!(flags & MSG_PEEK)) trace_rxrpc_receive(call, rxrpc_receive_front, sp->hdr.serial, seq); if (msg) sock_recv_timestamp(msg, sock->sk, skb); if (rx_pkt_offset == 0) { ret2 = rxrpc_locate_data(call, skb, &call->rxtx_annotations[ix], &rx_pkt_offset, &rx_pkt_len); trace_rxrpc_recvmsg(call, rxrpc_recvmsg_next, seq, rx_pkt_offset, rx_pkt_len, ret2); if (ret2 < 0) { ret = ret2; goto out; } } else { trace_rxrpc_recvmsg(call, rxrpc_recvmsg_cont, seq, rx_pkt_offset, rx_pkt_len, 0); } /* We have to handle short, empty and used-up DATA packets. */ remain = len - *_offset; copy = rx_pkt_len; if (copy > remain) copy = remain; if (copy > 0) { ret2 = skb_copy_datagram_iter(skb, rx_pkt_offset, iter, copy); if (ret2 < 0) { ret = ret2; goto out; } /* handle piecemeal consumption of data packets */ rx_pkt_offset += copy; rx_pkt_len -= copy; *_offset += copy; } if (rx_pkt_len > 0) { trace_rxrpc_recvmsg(call, rxrpc_recvmsg_full, seq, rx_pkt_offset, rx_pkt_len, 0); ASSERTCMP(*_offset, ==, len); ret = 0; break; } /* The whole packet has been transferred. */ last = sp->hdr.flags & RXRPC_LAST_PACKET; if (!(flags & MSG_PEEK)) rxrpc_rotate_rx_window(call); rx_pkt_offset = 0; rx_pkt_len = 0; if (last) { ASSERTCMP(seq, ==, READ_ONCE(call->rx_top)); ret = 1; goto out; } }