git: 4a01b854ca5c - main - SO_RERROR indicates that receive buffer overflows should be handled as errors. Historically receive buffer overflows have been ignored and programs could not tell if they missed messages or messages had been truncated because of overflows. Since programs historically do not expect to get receive overflow errors, this behavior is not the default.
Alexander V. Chernikov
melifaro at FreeBSD.org
Mon Feb 8 21:42:28 UTC 2021
The branch main has been updated by melifaro:
URL: https://cgit.FreeBSD.org/src/commit/?id=4a01b854ca5c2e5124958363b3326708b913af71
commit 4a01b854ca5c2e5124958363b3326708b913af71
Author: Alexander V. Chernikov <melifaro at FreeBSD.org>
AuthorDate: 2021-02-07 17:21:18 +0000
Commit: Alexander V. Chernikov <melifaro at FreeBSD.org>
CommitDate: 2021-02-08 21:42:20 +0000
SO_RERROR indicates that receive buffer overflows should be handled as errors.
Historically receive buffer overflows have been ignored and programs
could not tell if they missed messages or messages had been truncated
because of overflows. Since programs historically do not expect to get
receive overflow errors, this behavior is not the default.
This is really really important for programs that use route(4) to keep in sync
with the system. If we loose a message then we need to reload the full system
state, otherwise the behaviour from that point is undefined and can lead
to chasing bogus bug reports.
---
lib/libc/sys/getsockopt.2 | 10 +++++++-
sbin/route/route.c | 13 +++++++++-
sys/kern/uipc_sockbuf.c | 24 +++++++++++++++++
sys/kern/uipc_socket.c | 30 ++++++++++++++++------
sys/kern/uipc_usrreq.c | 2 +-
sys/net/raw_usrreq.c | 11 ++++----
.../bluetooth/socket/ng_btsocket_hci_raw.c | 1 +
sys/netgraph/ng_socket.c | 2 +-
sys/netinet/ip_divert.c | 2 +-
sys/netinet/ip_mroute.c | 2 +-
sys/netinet/raw_ip.c | 3 +--
sys/netinet/udp_usrreq.c | 2 +-
sys/netinet6/icmp6.c | 6 ++---
sys/netinet6/ip6_input.c | 1 +
sys/netinet6/ip6_mroute.c | 3 ++-
sys/netinet6/raw_ip6.c | 2 ++
sys/netinet6/send.c | 2 +-
sys/netinet6/udp6_usrreq.c | 2 +-
sys/netipsec/keysock.c | 10 ++++----
sys/sys/socket.h | 1 +
sys/sys/socketvar.h | 6 ++++-
21 files changed, 100 insertions(+), 35 deletions(-)
diff --git a/lib/libc/sys/getsockopt.2 b/lib/libc/sys/getsockopt.2
index 1e4ed6827170..223eb3e8a28b 100644
--- a/lib/libc/sys/getsockopt.2
+++ b/lib/libc/sys/getsockopt.2
@@ -28,7 +28,7 @@
.\" @(#)getsockopt.2 8.4 (Berkeley) 5/2/95
.\" $FreeBSD$
.\"
-.Dd June 3, 2020
+.Dd Feb 07, 2020
.Dt GETSOCKOPT 2
.Os
.Sh NAME
@@ -177,6 +177,7 @@ for the socket
.It Dv SO_PROTOCOL Ta "get the protocol number for the socket (get only)"
.It Dv SO_PROTOTYPE Ta "SunOS alias for the Linux SO_PROTOCOL (get only)"
.It Dv SO_ERROR Ta "get and clear error on the socket (get only)"
+.It Dv SO_RERROR Ta "enables receive error reporting"
.It Dv SO_SETFIB Ta "set the associated FIB (routing table) for the socket (set only)"
.El
.Pp
@@ -514,6 +515,13 @@ returns any pending error on the socket and clears
the error status.
It may be used to check for asynchronous errors on connected
datagram sockets or for other asynchronous errors.
+.Dv SO_RERROR
+indicates that receive buffer overflows should be handled as errors.
+Historically receive buffer overflows have been ignored and programs
+could not tell if they missed messages or messages had been truncated
+because of overflows.
+Since programs historically do not expect to get receive overflow errors,
+this behavior is not the default.
.Pp
.Dv SO_LABEL
returns the MAC label of the socket.
diff --git a/sbin/route/route.c b/sbin/route/route.c
index 51a0c68746a6..b16fb6d17a08 100644
--- a/sbin/route/route.c
+++ b/sbin/route/route.c
@@ -1444,9 +1444,20 @@ monitor(int argc, char *argv[])
interfaces();
exit(0);
}
+
+#ifdef SO_RERROR
+ n = 1;
+ if (setsockopt(s, SOL_SOCKET, SO_RERROR, &n, sizeof(n)) == -1)
+ warn("SO_RERROR");
+#endif
+
for (;;) {
time_t now;
- n = read(s, msg, 2048);
+ n = read(s, msg, sizeof(msg));
+ if (n == -1) {
+ warn("read");
+ continue;
+ }
now = time(NULL);
(void)printf("\ngot message of size %d on %s", n, ctime(&now));
print_rtmsg((struct rt_msghdr *)(void *)msg, n);
diff --git a/sys/kern/uipc_sockbuf.c b/sys/kern/uipc_sockbuf.c
index cf53f234d8fc..b5ecdb99b59b 100644
--- a/sys/kern/uipc_sockbuf.c
+++ b/sys/kern/uipc_sockbuf.c
@@ -436,6 +436,30 @@ socantrcvmore(struct socket *so)
mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED);
}
+void
+soroverflow_locked(struct socket *so)
+{
+
+ SOCKBUF_LOCK_ASSERT(&so->so_rcv);
+
+ if (so->so_options & SO_RERROR) {
+ so->so_rerror = ENOBUFS;
+ sorwakeup_locked(so);
+ } else
+ SOCKBUF_UNLOCK(&so->so_rcv);
+
+ mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED);
+}
+
+void
+soroverflow(struct socket *so)
+{
+
+ SOCKBUF_LOCK(&so->so_rcv);
+ soroverflow_locked(so);
+ mtx_assert(SOCKBUF_MTX(&so->so_rcv), MA_NOTOWNED);
+}
+
/*
* Wait for data to arrive at/drain from a socket buffer.
*/
diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c
index 7b16401b7071..8d218cf10a81 100644
--- a/sys/kern/uipc_socket.c
+++ b/sys/kern/uipc_socket.c
@@ -1953,12 +1953,19 @@ restart:
KASSERT(m != NULL || !sbavail(&so->so_rcv),
("receive: m == %p sbavail == %u",
m, sbavail(&so->so_rcv)));
- if (so->so_error) {
+ if (so->so_error || so->so_rerror) {
if (m != NULL)
goto dontblock;
- error = so->so_error;
- if ((flags & MSG_PEEK) == 0)
- so->so_error = 0;
+ if (so->so_error)
+ error = so->so_error;
+ else
+ error = so->so_rerror;
+ if ((flags & MSG_PEEK) == 0) {
+ if (so->so_error)
+ so->so_error = 0;
+ else
+ so->so_rerror = 0;
+ }
SOCKBUF_UNLOCK(&so->so_rcv);
goto release;
}
@@ -2302,7 +2309,7 @@ dontblock:
while (flags & MSG_WAITALL && m == NULL && uio->uio_resid > 0 &&
!sosendallatonce(so) && nextrecord == NULL) {
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
- if (so->so_error ||
+ if (so->so_error || so->so_rerror ||
so->so_rcv.sb_state & SBS_CANTRCVMORE)
break;
/*
@@ -3043,6 +3050,7 @@ sosetopt(struct socket *so, struct sockopt *sopt)
case SO_NOSIGPIPE:
case SO_NO_DDP:
case SO_NO_OFFLOAD:
+ case SO_RERROR:
error = sooptcopyin(sopt, &optval, sizeof optval,
sizeof optval);
if (error)
@@ -3264,6 +3272,7 @@ sogetopt(struct socket *so, struct sockopt *sopt)
case SO_NOSIGPIPE:
case SO_NO_DDP:
case SO_NO_OFFLOAD:
+ case SO_RERROR:
optval = so->so_options & sopt->sopt_name;
integer:
error = sooptcopyout(sopt, &optval, sizeof optval);
@@ -3283,8 +3292,13 @@ integer:
case SO_ERROR:
SOCK_LOCK(so);
- optval = so->so_error;
- so->so_error = 0;
+ if (so->so_error) {
+ optval = so->so_error;
+ so->so_error = 0;
+ } else {
+ optval = so->so_rerror;
+ so->so_rerror = 0;
+ }
SOCK_UNLOCK(so);
goto integer;
@@ -3833,7 +3847,7 @@ filt_soread(struct knote *kn, long hint)
kn->kn_flags |= EV_EOF;
kn->kn_fflags = so->so_error;
return (1);
- } else if (so->so_error) /* temporary udp error */
+ } else if (so->so_error || so->so_rerror)
return (1);
if (kn->kn_sfflags & NOTE_LOWAT) {
diff --git a/sys/kern/uipc_usrreq.c b/sys/kern/uipc_usrreq.c
index 0809f5180cc1..10680ad88136 100644
--- a/sys/kern/uipc_usrreq.c
+++ b/sys/kern/uipc_usrreq.c
@@ -1058,7 +1058,7 @@ uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
m = NULL;
control = NULL;
} else {
- SOCKBUF_UNLOCK(&so2->so_rcv);
+ soroverflow_locked(so2);
error = ENOBUFS;
}
if (nam != NULL)
diff --git a/sys/net/raw_usrreq.c b/sys/net/raw_usrreq.c
index f43de7dae9ca..5d4e223e5a0a 100644
--- a/sys/net/raw_usrreq.c
+++ b/sys/net/raw_usrreq.c
@@ -100,10 +100,10 @@ raw_input_ext(struct mbuf *m0, struct sockproto *proto, struct sockaddr *src,
n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
if (n) {
if (sbappendaddr(&last->so_rcv, src,
- n, (struct mbuf *)0) == 0)
- /* should notify about lost packet */
+ n, (struct mbuf *)0) == 0) {
+ soroverflow(last);
m_freem(n);
- else
+ } else
sorwakeup(last);
}
}
@@ -111,9 +111,10 @@ raw_input_ext(struct mbuf *m0, struct sockproto *proto, struct sockaddr *src,
}
if (last) {
if (sbappendaddr(&last->so_rcv, src,
- m, (struct mbuf *)0) == 0)
+ m, (struct mbuf *)0) == 0) {
+ soroverflow(last);
m_freem(m);
- else
+ } else
sorwakeup(last);
} else
m_freem(m);
diff --git a/sys/netgraph/bluetooth/socket/ng_btsocket_hci_raw.c b/sys/netgraph/bluetooth/socket/ng_btsocket_hci_raw.c
index 5f6b98d03359..c82515f82631 100644
--- a/sys/netgraph/bluetooth/socket/ng_btsocket_hci_raw.c
+++ b/sys/netgraph/bluetooth/socket/ng_btsocket_hci_raw.c
@@ -539,6 +539,7 @@ ng_btsocket_hci_raw_data_input(struct mbuf *nam)
NG_FREE_M(m);
NG_FREE_M(ctl);
+ soroverflow(pcb->so);
}
}
next:
diff --git a/sys/netgraph/ng_socket.c b/sys/netgraph/ng_socket.c
index 865e9dd7948f..905567c86b47 100644
--- a/sys/netgraph/ng_socket.c
+++ b/sys/netgraph/ng_socket.c
@@ -982,7 +982,7 @@ ngs_rcvmsg(node_p node, item_p item, hook_p lasthook)
/* Send it up to the socket. */
if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)&addr, m,
NULL) == 0) {
- SOCKBUF_UNLOCK(&so->so_rcv);
+ soroverflow_locked(so);
TRAP_ERROR;
m_freem(m);
return (ENOBUFS);
diff --git a/sys/netinet/ip_divert.c b/sys/netinet/ip_divert.c
index 65f1d263b5fa..99a8405fe334 100644
--- a/sys/netinet/ip_divert.c
+++ b/sys/netinet/ip_divert.c
@@ -285,7 +285,7 @@ divert_packet(struct mbuf *m, bool incoming)
if (sbappendaddr_locked(&sa->so_rcv,
(struct sockaddr *)&divsrc, m,
(struct mbuf *)0) == 0) {
- SOCKBUF_UNLOCK(&sa->so_rcv);
+ soroverflow_locked(sa);
sa = NULL; /* force mbuf reclaim below */
} else
sorwakeup_locked(sa);
diff --git a/sys/netinet/ip_mroute.c b/sys/netinet/ip_mroute.c
index b66fe8df0793..6aeea44f631c 100644
--- a/sys/netinet/ip_mroute.c
+++ b/sys/netinet/ip_mroute.c
@@ -1199,7 +1199,7 @@ socket_send(struct socket *s, struct mbuf *mm, struct sockaddr_in *src)
sorwakeup_locked(s);
return 0;
}
- SOCKBUF_UNLOCK(&s->so_rcv);
+ soroverflow_locked(s);
}
m_freem(mm);
return -1;
diff --git a/sys/netinet/raw_ip.c b/sys/netinet/raw_ip.c
index c9def015343c..1df54a8cfdba 100644
--- a/sys/netinet/raw_ip.c
+++ b/sys/netinet/raw_ip.c
@@ -263,11 +263,10 @@ rip_append(struct inpcb *last, struct ip *ip, struct mbuf *n,
SOCKBUF_LOCK(&so->so_rcv);
if (sbappendaddr_locked(&so->so_rcv,
(struct sockaddr *)ripsrc, n, opts) == 0) {
- /* should notify about lost packet */
+ soroverflow_locked(so);
m_freem(n);
if (opts)
m_freem(opts);
- SOCKBUF_UNLOCK(&so->so_rcv);
} else
sorwakeup_locked(so);
} else
diff --git a/sys/netinet/udp_usrreq.c b/sys/netinet/udp_usrreq.c
index 52304ddd6584..6392c6c441d6 100644
--- a/sys/netinet/udp_usrreq.c
+++ b/sys/netinet/udp_usrreq.c
@@ -379,7 +379,7 @@ udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
so = inp->inp_socket;
SOCKBUF_LOCK(&so->so_rcv);
if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
- SOCKBUF_UNLOCK(&so->so_rcv);
+ soroverflow(so);
m_freem(n);
if (opts)
m_freem(opts);
diff --git a/sys/netinet6/icmp6.c b/sys/netinet6/icmp6.c
index 1a08dad7de64..71007d5e9d11 100644
--- a/sys/netinet6/icmp6.c
+++ b/sys/netinet6/icmp6.c
@@ -1973,13 +1973,11 @@ icmp6_rip6_input(struct mbuf **mp, int off)
&last->inp_socket->so_rcv,
(struct sockaddr *)&fromsa, n, opts)
== 0) {
- /* should notify about lost packet */
+ soroverflow_locked(last->inp_socket);
m_freem(n);
if (opts) {
m_freem(opts);
}
- SOCKBUF_UNLOCK(
- &last->inp_socket->so_rcv);
} else
sorwakeup_locked(last->inp_socket);
opts = NULL;
@@ -2019,7 +2017,7 @@ icmp6_rip6_input(struct mbuf **mp, int off)
m_freem(m);
if (opts)
m_freem(opts);
- SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
+ soroverflow_locked(last->inp_socket);
} else
sorwakeup_locked(last->inp_socket);
INP_RUNLOCK(last);
diff --git a/sys/netinet6/ip6_input.c b/sys/netinet6/ip6_input.c
index 8f500cb87bfe..9a4fd20a52b8 100644
--- a/sys/netinet6/ip6_input.c
+++ b/sys/netinet6/ip6_input.c
@@ -1576,6 +1576,7 @@ ip6_notify_pmtu(struct inpcb *inp, struct sockaddr_in6 *dst, u_int32_t mtu)
so = inp->inp_socket;
if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu)
== 0) {
+ soroverflow(so);
m_freem(m_mtu);
/* XXX: should count statistics */
} else
diff --git a/sys/netinet6/ip6_mroute.c b/sys/netinet6/ip6_mroute.c
index d2277e41110c..503c83490940 100644
--- a/sys/netinet6/ip6_mroute.c
+++ b/sys/netinet6/ip6_mroute.c
@@ -1038,7 +1038,8 @@ socket_send(struct socket *s, struct mbuf *mm, struct sockaddr_in6 *src)
mm, (struct mbuf *)0) != 0) {
sorwakeup(s);
return (0);
- }
+ } else
+ soroverflow(s);
}
m_freem(mm);
return (-1);
diff --git a/sys/netinet6/raw_ip6.c b/sys/netinet6/raw_ip6.c
index aea99add4391..92fe8b7e2253 100644
--- a/sys/netinet6/raw_ip6.c
+++ b/sys/netinet6/raw_ip6.c
@@ -214,6 +214,7 @@ rip6_input(struct mbuf **mp, int *offp, int proto)
if (sbappendaddr(&last->inp_socket->so_rcv,
(struct sockaddr *)&fromsa,
n, opts) == 0) {
+ soroverflow(last->inp_socket);
m_freem(n);
if (opts)
m_freem(opts);
@@ -325,6 +326,7 @@ skip_2:
m_adj(m, *offp);
if (sbappendaddr(&last->inp_socket->so_rcv,
(struct sockaddr *)&fromsa, m, opts) == 0) {
+ soroverflow(last->inp_socket);
m_freem(m);
if (opts)
m_freem(opts);
diff --git a/sys/netinet6/send.c b/sys/netinet6/send.c
index bc9880c82267..8458ef367cba 100644
--- a/sys/netinet6/send.c
+++ b/sys/netinet6/send.c
@@ -291,7 +291,7 @@ send_input(struct mbuf *m, struct ifnet *ifp, int direction, int msglen __unused
SOCKBUF_LOCK(&V_send_so->so_rcv);
if (sbappendaddr_locked(&V_send_so->so_rcv,
(struct sockaddr *)&sendsrc, m, NULL) == 0) {
- SOCKBUF_UNLOCK(&V_send_so->so_rcv);
+ soroverflow_locked(V_send_so);
/* XXX stats. */
m_freem(m);
} else {
diff --git a/sys/netinet6/udp6_usrreq.c b/sys/netinet6/udp6_usrreq.c
index 1535be90e1b0..bc1d8cc5b2fa 100644
--- a/sys/netinet6/udp6_usrreq.c
+++ b/sys/netinet6/udp6_usrreq.c
@@ -197,7 +197,7 @@ udp6_append(struct inpcb *inp, struct mbuf *n, int off,
SOCKBUF_LOCK(&so->so_rcv);
if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)&fromsa[0], n,
opts) == 0) {
- SOCKBUF_UNLOCK(&so->so_rcv);
+ soroverflow_locked(so);
m_freem(n);
if (opts)
m_freem(opts);
diff --git a/sys/netipsec/keysock.c b/sys/netipsec/keysock.c
index 49efa0a3c510..7a0b9e757022 100644
--- a/sys/netipsec/keysock.c
+++ b/sys/netipsec/keysock.c
@@ -141,7 +141,6 @@ end:
static int
key_sendup0(struct rawcb *rp, struct mbuf *m, int promisc)
{
- int error;
if (promisc) {
struct sadb_msg *pmsg;
@@ -165,11 +164,12 @@ key_sendup0(struct rawcb *rp, struct mbuf *m, int promisc)
m, NULL)) {
PFKEYSTAT_INC(in_nomem);
m_freem(m);
- error = ENOBUFS;
- } else
- error = 0;
+ soroverflow(rp->rcb_socket);
+ return ENOBUFS;
+ }
+
sorwakeup(rp->rcb_socket);
- return error;
+ return 0;
}
/* so can be NULL if target != KEY_SENDUP_ONE */
diff --git a/sys/sys/socket.h b/sys/sys/socket.h
index d9256fd7544a..2cb76f9c6d63 100644
--- a/sys/sys/socket.h
+++ b/sys/sys/socket.h
@@ -147,6 +147,7 @@ typedef __uintptr_t uintptr_t;
#define SO_NO_OFFLOAD 0x00004000 /* socket cannot be offloaded */
#define SO_NO_DDP 0x00008000 /* disable direct data placement */
#define SO_REUSEPORT_LB 0x00010000 /* reuse with load balancing */
+#define SO_RERROR 0x00020000 /* keep track of receive errors */
/*
* Additional options, not kept in so_options.
diff --git a/sys/sys/socketvar.h b/sys/sys/socketvar.h
index 295a1cf3d37f..60a4dde7f0cb 100644
--- a/sys/sys/socketvar.h
+++ b/sys/sys/socketvar.h
@@ -100,6 +100,7 @@ struct socket {
struct protosw *so_proto; /* (a) protocol handle */
short so_timeo; /* (g) connection timeout */
u_short so_error; /* (f) error affecting connection */
+ u_short so_rerror; /* (f) error affecting connection */
struct sigio *so_sigio; /* [sg] information for async I/O or
out of band data (SIGURG) */
struct ucred *so_cred; /* (a) user credentials */
@@ -266,7 +267,8 @@ struct socket {
/* can we read something from so? */
#define soreadabledata(so) \
- (sbavail(&(so)->so_rcv) >= (so)->so_rcv.sb_lowat || (so)->so_error)
+ (sbavail(&(so)->so_rcv) >= (so)->so_rcv.sb_lowat || \
+ (so)->so_error || (so)->so_rerror)
#define soreadable(so) \
(soreadabledata(so) || ((so)->so_rcv.sb_state & SBS_CANTRCVMORE))
@@ -480,6 +482,8 @@ void socantrcvmore(struct socket *so);
void socantrcvmore_locked(struct socket *so);
void socantsendmore(struct socket *so);
void socantsendmore_locked(struct socket *so);
+void soroverflow(struct socket *so);
+void soroverflow_locked(struct socket *so);
/*
* Accept filter functions (duh).
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