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-rw-r--r--net/core/datagram.c26
-rw-r--r--net/core/sock.c13
-rw-r--r--net/ipv4/udp.c4
-rw-r--r--net/ipv6/udp.c4
-rw-r--r--net/unix/af_unix.c50
5 files changed, 76 insertions, 21 deletions
diff --git a/net/core/datagram.c b/net/core/datagram.c
index 68bbf9f65cb..d3cf12f62c8 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -132,6 +132,8 @@ out_noerr:
* __skb_recv_datagram - Receive a datagram skbuff
* @sk: socket
* @flags: MSG_ flags
+ * @off: an offset in bytes to peek skb from. Returns an offset
+ * within an skb where data actually starts
* @peeked: returns non-zero if this packet has been seen before
* @err: error code returned
*
@@ -158,7 +160,7 @@ out_noerr:
* the standard around please.
*/
struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
- int *peeked, int *err)
+ int *peeked, int *off, int *err)
{
struct sk_buff *skb;
long timeo;
@@ -180,21 +182,25 @@ struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
* However, this function was correct in any case. 8)
*/
unsigned long cpu_flags;
+ struct sk_buff_head *queue = &sk->sk_receive_queue;
- spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags);
- skb = skb_peek(&sk->sk_receive_queue);
- if (skb) {
+ spin_lock_irqsave(&queue->lock, cpu_flags);
+ skb_queue_walk(queue, skb) {
*peeked = skb->peeked;
if (flags & MSG_PEEK) {
+ if (*off >= skb->len) {
+ *off -= skb->len;
+ continue;
+ }
skb->peeked = 1;
atomic_inc(&skb->users);
} else
- __skb_unlink(skb, &sk->sk_receive_queue);
- }
- spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags);
+ __skb_unlink(skb, queue);
- if (skb)
+ spin_unlock_irqrestore(&queue->lock, cpu_flags);
return skb;
+ }
+ spin_unlock_irqrestore(&queue->lock, cpu_flags);
/* User doesn't want to wait */
error = -EAGAIN;
@@ -214,10 +220,10 @@ EXPORT_SYMBOL(__skb_recv_datagram);
struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
int noblock, int *err)
{
- int peeked;
+ int peeked, off = 0;
return __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
- &peeked, err);
+ &peeked, &off, err);
}
EXPORT_SYMBOL(skb_recv_datagram);
diff --git a/net/core/sock.c b/net/core/sock.c
index 02f8dfe320b..19942d4bb6e 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -793,6 +793,12 @@ set_rcvbuf:
sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
break;
+ case SO_PEEK_OFF:
+ if (sock->ops->set_peek_off)
+ sock->ops->set_peek_off(sk, val);
+ else
+ ret = -EOPNOTSUPP;
+ break;
default:
ret = -ENOPROTOOPT;
break;
@@ -1018,6 +1024,12 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
v.val = !!sock_flag(sk, SOCK_WIFI_STATUS);
break;
+ case SO_PEEK_OFF:
+ if (!sock->ops->set_peek_off)
+ return -EOPNOTSUPP;
+
+ v.val = sk->sk_peek_off;
+ break;
default:
return -ENOPROTOOPT;
}
@@ -2092,6 +2104,7 @@ void sock_init_data(struct socket *sock, struct sock *sk)
sk->sk_sndmsg_page = NULL;
sk->sk_sndmsg_off = 0;
+ sk->sk_peek_off = -1;
sk->sk_peer_pid = NULL;
sk->sk_peer_cred = NULL;
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index cd99f1a0f59..7c41ab84e72 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1167,7 +1167,7 @@ int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
struct sk_buff *skb;
unsigned int ulen, copied;
- int peeked;
+ int peeked, off = 0;
int err;
int is_udplite = IS_UDPLITE(sk);
bool slow;
@@ -1183,7 +1183,7 @@ int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
try_again:
skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
- &peeked, &err);
+ &peeked, &off, &err);
if (!skb)
goto out;
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 8aebf8f9043..37b0699e95e 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -342,7 +342,7 @@ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
struct inet_sock *inet = inet_sk(sk);
struct sk_buff *skb;
unsigned int ulen, copied;
- int peeked;
+ int peeked, off = 0;
int err;
int is_udplite = IS_UDPLITE(sk);
int is_udp4;
@@ -359,7 +359,7 @@ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
try_again:
skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
- &peeked, &err);
+ &peeked, &off, &err);
if (!skb)
goto out;
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 85d3bb7490a..0be4d24f6ae 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -530,6 +530,16 @@ static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *,
static int unix_seqpacket_recvmsg(struct kiocb *, struct socket *,
struct msghdr *, size_t, int);
+static void unix_set_peek_off(struct sock *sk, int val)
+{
+ struct unix_sock *u = unix_sk(sk);
+
+ mutex_lock(&u->readlock);
+ sk->sk_peek_off = val;
+ mutex_unlock(&u->readlock);
+}
+
+
static const struct proto_ops unix_stream_ops = {
.family = PF_UNIX,
.owner = THIS_MODULE,
@@ -549,6 +559,7 @@ static const struct proto_ops unix_stream_ops = {
.recvmsg = unix_stream_recvmsg,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage,
+ .set_peek_off = unix_set_peek_off,
};
static const struct proto_ops unix_dgram_ops = {
@@ -570,6 +581,7 @@ static const struct proto_ops unix_dgram_ops = {
.recvmsg = unix_dgram_recvmsg,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage,
+ .set_peek_off = unix_set_peek_off,
};
static const struct proto_ops unix_seqpacket_ops = {
@@ -591,6 +603,7 @@ static const struct proto_ops unix_seqpacket_ops = {
.recvmsg = unix_seqpacket_recvmsg,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage,
+ .set_peek_off = unix_set_peek_off,
};
static struct proto unix_proto = {
@@ -1756,6 +1769,7 @@ static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
int noblock = flags & MSG_DONTWAIT;
struct sk_buff *skb;
int err;
+ int peeked, skip;
err = -EOPNOTSUPP;
if (flags&MSG_OOB)
@@ -1769,7 +1783,9 @@ static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
goto out;
}
- skb = skb_recv_datagram(sk, flags, noblock, &err);
+ skip = sk_peek_offset(sk, flags);
+
+ skb = __skb_recv_datagram(sk, flags, &peeked, &skip, &err);
if (!skb) {
unix_state_lock(sk);
/* Signal EOF on disconnected non-blocking SEQPACKET socket. */
@@ -1786,12 +1802,12 @@ static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
if (msg->msg_name)
unix_copy_addr(msg, skb->sk);
- if (size > skb->len)
- size = skb->len;
- else if (size < skb->len)
+ if (size > skb->len - skip)
+ size = skb->len - skip;
+ else if (size < skb->len - skip)
msg->msg_flags |= MSG_TRUNC;
- err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, size);
+ err = skb_copy_datagram_iovec(skb, skip, msg->msg_iov, size);
if (err)
goto out_free;
@@ -1808,6 +1824,8 @@ static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
if (!(flags & MSG_PEEK)) {
if (UNIXCB(skb).fp)
unix_detach_fds(siocb->scm, skb);
+
+ sk_peek_offset_bwd(sk, skb->len);
} else {
/* It is questionable: on PEEK we could:
- do not return fds - good, but too simple 8)
@@ -1821,6 +1839,9 @@ static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
clearly however!
*/
+
+ sk_peek_offset_fwd(sk, size);
+
if (UNIXCB(skb).fp)
siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
}
@@ -1884,6 +1905,7 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
int target;
int err = 0;
long timeo;
+ int skip;
err = -EINVAL;
if (sk->sk_state != TCP_ESTABLISHED)
@@ -1913,12 +1935,15 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
goto out;
}
+ skip = sk_peek_offset(sk, flags);
+
do {
int chunk;
struct sk_buff *skb;
unix_state_lock(sk);
skb = skb_peek(&sk->sk_receive_queue);
+again:
if (skb == NULL) {
unix_sk(sk)->recursion_level = 0;
if (copied >= target)
@@ -1953,6 +1978,13 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
unix_state_unlock(sk);
break;
}
+
+ if (skip >= skb->len) {
+ skip -= skb->len;
+ skb = skb_peek_next(skb, &sk->sk_receive_queue);
+ goto again;
+ }
+
unix_state_unlock(sk);
if (check_creds) {
@@ -1972,8 +2004,8 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
sunaddr = NULL;
}
- chunk = min_t(unsigned int, skb->len, size);
- if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
+ chunk = min_t(unsigned int, skb->len - skip, size);
+ if (memcpy_toiovec(msg->msg_iov, skb->data + skip, chunk)) {
if (copied == 0)
copied = -EFAULT;
break;
@@ -1985,6 +2017,8 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
if (!(flags & MSG_PEEK)) {
skb_pull(skb, chunk);
+ sk_peek_offset_bwd(sk, chunk);
+
if (UNIXCB(skb).fp)
unix_detach_fds(siocb->scm, skb);
@@ -2002,6 +2036,8 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
if (UNIXCB(skb).fp)
siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
+ sk_peek_offset_fwd(sk, chunk);
+
break;
}
} while (size);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-03-21 19:39:21 +0000