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qemu/util/qemu-sockets.c
Daniel P. Berrangé b5b89e9bc6 util: don't set SO_REUSEADDR on client sockets 
Setting the SO_REUSEADDR property on a socket allows binding to a port
number that is in the TIMED_WAIT state. This is usually done on listener
sockets, to enable a server to restart itself without having to wait for
the completion of TIMED_WAIT on the port.

It is also possible, but highly unusual, to set it on client sockets. It
is rare to explicitly bind() a client socket, since it is almost always
fine to allow the kernel to auto-bind a client socket to a random free
port. Most systems will have many 10's of 1000's of free ports that
client sockets will be bound to.

eg on Linux

  $ sysctl -a | grep local_port
  net.ipv4.ip_local_port_range = 32768	60999

eg on OpenBSD

  $ sysctl -a | grep net.inet.ip.port
  net.inet.ip.portfirst=1024
  net.inet.ip.portlast=49151
  net.inet.ip.porthifirst=49152
  net.inet.ip.porthilast=65535

A connected socket must have a unique set of value for

 (protocol, localip, localport, remoteip, remoteport)

otherwise it is liable to get EADDRINUSE.

A client connection should trivially avoid EADDRINUSE if letting the
kernel auto-assign the 'localport' value, which QEMU always does.

When QEMU sets SO_REUSEADDR on a client socket on OpenBSD, however, it
upsets this situation.

The OpenBSD kernel appears to happily pick a 'localport' that is in the
TIMED_WAIT state, even if there are many other available local ports
available for use that are not in the TIMED_WAIT state.

A test program that just loops opening client sockets will start seeing
EADDRINUSE on OpenBSD when as few as 2000 ports are in TIMED_WAIT,
despite 10's of 1000's ports still being unused. This contrasts with
Linux which appears to avoid picking local ports in TIMED_WAIT state.

This problem on OpenBSD exhibits itself periodically with the migration
test failing with a message like[1]:

  qemu-system-ppc64: Failed to connect to '127.0.0.1:24109': Address already in use

While I have not been able to reproduce the OpenBSD failure in my own
testing, given the scope of what QEMU tests do, it is entirely possible
that there could be a lot of ports in TIMED_WAIT state when the
migration test runs.

Removing SO_REUSEADDR from the client sockets should not affect normal
QEMU usage, and should improve reliability on OpenBSD.

This use of SO_REUSEADDR on client sockets is highly unusual, and
appears to have been present since the very start of the QEMU socket
helpers in 2008. The orignal commit has no comment about the use of
SO_REUSEADDR on the client, so is most likely just an 16 year old
copy+paste bug.

[1] https://lists.nongnu.org/archive/html/qemu-devel/2024-10/msg03427.html
    https://lists.nongnu.org/archive/html/qemu-devel/2024-02/msg01572.html

Fixes: d247d25f18
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2024-10-22 11:44:23 +01:00

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/*
* inet and unix socket functions for qemu
*
* (c) 2008 Gerd Hoffmann <kraxel@redhat.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; under version 2 of the License.
*
* 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.
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#include "qemu/osdep.h"
#ifdef CONFIG_AF_VSOCK
#include <linux/vm_sockets.h>
#endif /* CONFIG_AF_VSOCK */
#include "monitor/monitor.h"
#include "qapi/clone-visitor.h"
#include "qapi/error.h"
#include "qapi/qapi-visit-sockets.h"
#include "qemu/sockets.h"
#include "qemu/main-loop.h"
#include "qapi/qobject-input-visitor.h"
#include "qapi/qobject-output-visitor.h"
#include "qemu/cutils.h"
#include "trace.h"
#ifndef AI_ADDRCONFIG
# define AI_ADDRCONFIG 0
#endif
#ifndef AI_V4MAPPED
# define AI_V4MAPPED 0
#endif
#ifndef AI_NUMERICSERV
# define AI_NUMERICSERV 0
#endif
static int inet_getport(struct addrinfo *e)
{
struct sockaddr_in *i4;
struct sockaddr_in6 *i6;
switch (e->ai_family) {
case PF_INET6:
i6 = (void*)e->ai_addr;
return ntohs(i6->sin6_port);
case PF_INET:
i4 = (void*)e->ai_addr;
return ntohs(i4->sin_port);
default:
return 0;
}
}
static void inet_setport(struct addrinfo *e, int port)
{
struct sockaddr_in *i4;
struct sockaddr_in6 *i6;
switch (e->ai_family) {
case PF_INET6:
i6 = (void*)e->ai_addr;
i6->sin6_port = htons(port);
break;
case PF_INET:
i4 = (void*)e->ai_addr;
i4->sin_port = htons(port);
break;
}
}
NetworkAddressFamily inet_netfamily(int family)
{
switch (family) {
case PF_INET6: return NETWORK_ADDRESS_FAMILY_IPV6;
case PF_INET: return NETWORK_ADDRESS_FAMILY_IPV4;
case PF_UNIX: return NETWORK_ADDRESS_FAMILY_UNIX;
#ifdef CONFIG_AF_VSOCK
case PF_VSOCK: return NETWORK_ADDRESS_FAMILY_VSOCK;
#endif /* CONFIG_AF_VSOCK */
}
return NETWORK_ADDRESS_FAMILY_UNKNOWN;
}
bool fd_is_socket(int fd)
{
int optval;
socklen_t optlen = sizeof(optval);
return !getsockopt(fd, SOL_SOCKET, SO_TYPE, &optval, &optlen);
}
/*
* Matrix we're trying to apply
*
* ipv4 ipv6 family
* - - PF_UNSPEC
* - f PF_INET
* - t PF_INET6
* f - PF_INET6
* f f <error>
* f t PF_INET6
* t - PF_INET
* t f PF_INET
* t t PF_INET6/PF_UNSPEC
*
* NB, this matrix is only about getting the necessary results
* from getaddrinfo(). Some of the cases require further work
* after reading results from getaddrinfo in order to fully
* apply the logic the end user wants.
*
* In the first and last cases, we must set IPV6_V6ONLY=0
* when binding, to allow a single listener to potentially
* accept both IPv4+6 addresses.
*/
int inet_ai_family_from_address(InetSocketAddress *addr,
Error **errp)
{
if (addr->has_ipv6 && addr->has_ipv4 &&
!addr->ipv6 && !addr->ipv4) {
error_setg(errp, "Cannot disable IPv4 and IPv6 at same time");
return PF_UNSPEC;
}
if ((addr->has_ipv6 && addr->ipv6) && (addr->has_ipv4 && addr->ipv4)) {
/*
* Some backends can only do a single listener. In that case
* we want empty hostname to resolve to "::" and then use the
* flag IPV6_V6ONLY==0 to get both protocols on 1 socket. This
* doesn't work for addresses other than "", so they're just
* inevitably broken until multiple listeners can be used,
* and thus we honour getaddrinfo automatic protocol detection
* Once all backends do multi-listener, remove the PF_INET6
* branch entirely.
*/
if (!addr->host || g_str_equal(addr->host, "")) {
return PF_INET6;
} else {
return PF_UNSPEC;
}
}
if ((addr->has_ipv6 && addr->ipv6) || (addr->has_ipv4 && !addr->ipv4)) {
return PF_INET6;
}
if ((addr->has_ipv4 && addr->ipv4) || (addr->has_ipv6 && !addr->ipv6)) {
return PF_INET;
}
return PF_UNSPEC;
}
static int create_fast_reuse_socket(struct addrinfo *e)
{
int slisten = qemu_socket(e->ai_family, e->ai_socktype, e->ai_protocol);
if (slisten < 0) {
return -1;
}
socket_set_fast_reuse(slisten);
return slisten;
}
static int try_bind(int socket, InetSocketAddress *saddr, struct addrinfo *e)
{
#ifndef IPV6_V6ONLY
return bind(socket, e->ai_addr, e->ai_addrlen);
#else
/*
* Deals with first & last cases in matrix in comment
* for inet_ai_family_from_address().
*/
int v6only =
((!saddr->has_ipv4 && !saddr->has_ipv6) ||
(saddr->has_ipv4 && saddr->ipv4 &&
saddr->has_ipv6 && saddr->ipv6)) ? 0 : 1;
int stat;
rebind:
if (e->ai_family == PF_INET6) {
setsockopt(socket, IPPROTO_IPV6, IPV6_V6ONLY, &v6only,
sizeof(v6only));
}
stat = bind(socket, e->ai_addr, e->ai_addrlen);
if (!stat) {
return 0;
}
/* If we got EADDRINUSE from an IPv6 bind & v6only is unset,
* it could be that the IPv4 port is already claimed, so retry
* with v6only set
*/
if (e->ai_family == PF_INET6 && errno == EADDRINUSE && !v6only) {
v6only = 1;
goto rebind;
}
return stat;
#endif
}
static int inet_listen_saddr(InetSocketAddress *saddr,
int port_offset,
int num,
Error **errp)
{
ERRP_GUARD();
struct addrinfo ai, *res, *e;
char port[33];
char uaddr[INET6_ADDRSTRLEN+1];
char uport[33];
int rc, port_min, port_max, p;
int slisten = -1;
int saved_errno = 0;
bool socket_created = false;
if (saddr->keep_alive) {
error_setg(errp, "keep-alive option is not supported for passive "
"sockets");
return -1;
}
memset(&ai,0, sizeof(ai));
ai.ai_flags = AI_PASSIVE;
if (saddr->has_numeric && saddr->numeric) {
ai.ai_flags |= AI_NUMERICHOST | AI_NUMERICSERV;
}
ai.ai_socktype = SOCK_STREAM;
ai.ai_family = inet_ai_family_from_address(saddr, errp);
if (*errp) {
return -1;
}
if (saddr->host == NULL) {
error_setg(errp, "host not specified");
return -1;
}
if (saddr->port != NULL) {
pstrcpy(port, sizeof(port), saddr->port);
} else {
port[0] = '\0';
}
/* lookup */
if (port_offset) {
uint64_t baseport;
if (strlen(port) == 0) {
error_setg(errp, "port not specified");
return -1;
}
if (parse_uint_full(port, 10, &baseport) < 0) {
error_setg(errp, "can't convert to a number: %s", port);
return -1;
}
if (baseport > 65535 ||
baseport + port_offset > 65535) {
error_setg(errp, "port %s out of range", port);
return -1;
}
snprintf(port, sizeof(port), "%d", (int)baseport + port_offset);
}
rc = getaddrinfo(strlen(saddr->host) ? saddr->host : NULL,
strlen(port) ? port : NULL, &ai, &res);
if (rc != 0) {
error_setg(errp, "address resolution failed for %s:%s: %s",
saddr->host, port, gai_strerror(rc));
return -1;
}
/* create socket + bind/listen */
for (e = res; e != NULL; e = e->ai_next) {
#ifdef HAVE_IPPROTO_MPTCP
if (saddr->has_mptcp && saddr->mptcp) {
e->ai_protocol = IPPROTO_MPTCP;
}
#endif
getnameinfo((struct sockaddr*)e->ai_addr,e->ai_addrlen,
uaddr,INET6_ADDRSTRLEN,uport,32,
NI_NUMERICHOST | NI_NUMERICSERV);
port_min = inet_getport(e);
port_max = saddr->has_to ? saddr->to + port_offset : port_min;
for (p = port_min; p <= port_max; p++) {
inet_setport(e, p);
slisten = create_fast_reuse_socket(e);
if (slisten < 0) {
/* First time we expect we might fail to create the socket
* eg if 'e' has AF_INET6 but ipv6 kmod is not loaded.
* Later iterations should always succeed if first iteration
* worked though, so treat that as fatal.
*/
if (p == port_min) {
continue;
} else {
error_setg_errno(errp, errno,
"Failed to recreate failed listening socket");
goto listen_failed;
}
}
socket_created = true;
rc = try_bind(slisten, saddr, e);
if (rc < 0) {
if (errno != EADDRINUSE) {
error_setg_errno(errp, errno, "Failed to bind socket");
goto listen_failed;
}
} else {
if (!listen(slisten, num)) {
goto listen_ok;
}
if (errno != EADDRINUSE) {
error_setg_errno(errp, errno, "Failed to listen on socket");
goto listen_failed;
}
}
/* Someone else managed to bind to the same port and beat us
* to listen on it! Socket semantics does not allow us to
* recover from this situation, so we need to recreate the
* socket to allow bind attempts for subsequent ports:
*/
close(slisten);
slisten = -1;
}
}
error_setg_errno(errp, errno,
socket_created ?
"Failed to find an available port" :
"Failed to create a socket");
listen_failed:
saved_errno = errno;
if (slisten >= 0) {
close(slisten);
}
freeaddrinfo(res);
errno = saved_errno;
return -1;
listen_ok:
freeaddrinfo(res);
return slisten;
}
#ifdef _WIN32
#define QEMU_SOCKET_RC_INPROGRESS(rc) \
((rc) == -EINPROGRESS || (rc) == -EWOULDBLOCK || (rc) == -WSAEALREADY)
#else
#define QEMU_SOCKET_RC_INPROGRESS(rc) \
((rc) == -EINPROGRESS)
#endif
static int inet_connect_addr(const InetSocketAddress *saddr,
struct addrinfo *addr, Error **errp)
{
int sock, rc;
sock = qemu_socket(addr->ai_family, addr->ai_socktype, addr->ai_protocol);
if (sock < 0) {
error_setg_errno(errp, errno, "Failed to create socket family %d",
addr->ai_family);
return -1;
}
/* connect to peer */
do {
rc = 0;
if (connect(sock, addr->ai_addr, addr->ai_addrlen) < 0) {
rc = -errno;
}
} while (rc == -EINTR);
if (rc < 0) {
error_setg_errno(errp, errno, "Failed to connect to '%s:%s'",
saddr->host, saddr->port);
close(sock);
return -1;
}
return sock;
}
static struct addrinfo *inet_parse_connect_saddr(InetSocketAddress *saddr,
Error **errp)
{
ERRP_GUARD();
struct addrinfo ai, *res;
int rc;
static int useV4Mapped = 1;
memset(&ai, 0, sizeof(ai));
ai.ai_flags = AI_CANONNAME | AI_ADDRCONFIG;
if (qatomic_read(&useV4Mapped)) {
ai.ai_flags |= AI_V4MAPPED;
}
ai.ai_socktype = SOCK_STREAM;
ai.ai_family = inet_ai_family_from_address(saddr, errp);
if (*errp) {
return NULL;
}
if (saddr->host == NULL || saddr->port == NULL) {
error_setg(errp, "host and/or port not specified");
return NULL;
}
/* lookup */
rc = getaddrinfo(saddr->host, saddr->port, &ai, &res);
/* At least FreeBSD and OS-X 10.6 declare AI_V4MAPPED but
* then don't implement it in their getaddrinfo(). Detect
* this and retry without the flag since that's preferable
* to a fatal error
*/
if (rc == EAI_BADFLAGS &&
(ai.ai_flags & AI_V4MAPPED)) {
qatomic_set(&useV4Mapped, 0);
ai.ai_flags &= ~AI_V4MAPPED;
rc = getaddrinfo(saddr->host, saddr->port, &ai, &res);
}
if (rc != 0) {
error_setg(errp, "address resolution failed for %s:%s: %s",
saddr->host, saddr->port, gai_strerror(rc));
return NULL;
}
return res;
}
/**
* Create a socket and connect it to an address.
*
* @saddr: Inet socket address specification
* @errp: set on error
*
* Returns: -1 on error, file descriptor on success.
*/
int inet_connect_saddr(InetSocketAddress *saddr, Error **errp)
{
Error *local_err = NULL;
struct addrinfo *res, *e;
int sock = -1;
res = inet_parse_connect_saddr(saddr, errp);
if (!res) {
return -1;
}
for (e = res; e != NULL; e = e->ai_next) {
error_free(local_err);
local_err = NULL;
#ifdef HAVE_IPPROTO_MPTCP
if (saddr->has_mptcp && saddr->mptcp) {
e->ai_protocol = IPPROTO_MPTCP;
}
#endif
sock = inet_connect_addr(saddr, e, &local_err);
if (sock >= 0) {
break;
}
}
freeaddrinfo(res);
if (sock < 0) {
error_propagate(errp, local_err);
return sock;
}
if (saddr->keep_alive) {
int val = 1;
int ret = setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
&val, sizeof(val));
if (ret < 0) {
error_setg_errno(errp, errno, "Unable to set KEEPALIVE");
close(sock);
return -1;
}
}
return sock;
}
static int inet_dgram_saddr(InetSocketAddress *sraddr,
InetSocketAddress *sladdr,
Error **errp)
{
ERRP_GUARD();
struct addrinfo ai, *peer = NULL, *local = NULL;
const char *addr;
const char *port;
int sock = -1, rc;
/* lookup peer addr */
memset(&ai,0, sizeof(ai));
ai.ai_flags = AI_CANONNAME | AI_V4MAPPED | AI_ADDRCONFIG;
ai.ai_socktype = SOCK_DGRAM;
ai.ai_family = inet_ai_family_from_address(sraddr, errp);
if (*errp) {
goto err;
}
addr = sraddr->host;
port = sraddr->port;
if (addr == NULL || strlen(addr) == 0) {
addr = "localhost";
}
if (port == NULL || strlen(port) == 0) {
error_setg(errp, "remote port not specified");
goto err;
}
if ((rc = getaddrinfo(addr, port, &ai, &peer)) != 0) {
error_setg(errp, "address resolution failed for %s:%s: %s", addr, port,
gai_strerror(rc));
goto err;
}
/* lookup local addr */
memset(&ai,0, sizeof(ai));
ai.ai_flags = AI_PASSIVE;
ai.ai_family = peer->ai_family;
ai.ai_socktype = SOCK_DGRAM;
if (sladdr) {
addr = sladdr->host;
port = sladdr->port;
if (addr == NULL || strlen(addr) == 0) {
addr = NULL;
}
if (!port || strlen(port) == 0) {
port = "0";
}
} else {
addr = NULL;
port = "0";
}
if ((rc = getaddrinfo(addr, port, &ai, &local)) != 0) {
error_setg(errp, "address resolution failed for %s:%s: %s", addr, port,
gai_strerror(rc));
goto err;
}
/* create socket */
sock = qemu_socket(peer->ai_family, peer->ai_socktype, peer->ai_protocol);
if (sock < 0) {
error_setg_errno(errp, errno, "Failed to create socket family %d",
peer->ai_family);
goto err;
}
socket_set_fast_reuse(sock);
/* bind socket */
if (bind(sock, local->ai_addr, local->ai_addrlen) < 0) {
error_setg_errno(errp, errno, "Failed to bind socket");
goto err;
}
/* connect to peer */
if (connect(sock,peer->ai_addr,peer->ai_addrlen) < 0) {
error_setg_errno(errp, errno, "Failed to connect to '%s:%s'",
addr, port);
goto err;
}
freeaddrinfo(local);
freeaddrinfo(peer);
return sock;
err:
if (sock != -1) {
close(sock);
}
if (local) {
freeaddrinfo(local);
}
if (peer) {
freeaddrinfo(peer);
}
return -1;
}
/* compatibility wrapper */
static int inet_parse_flag(const char *flagname, const char *optstr, bool *val,
Error **errp)
{
char *end;
size_t len;
end = strstr(optstr, ",");
if (end) {
if (end[1] == ',') { /* Reject 'ipv6=on,,foo' */
error_setg(errp, "error parsing '%s' flag '%s'", flagname, optstr);
return -1;
}
len = end - optstr;
} else {
len = strlen(optstr);
}
if (len == 0 || (len == 3 && strncmp(optstr, "=on", len) == 0)) {
*val = true;
} else if (len == 4 && strncmp(optstr, "=off", len) == 0) {
*val = false;
} else {
error_setg(errp, "error parsing '%s' flag '%s'", flagname, optstr);
return -1;
}
return 0;
}
int inet_parse(InetSocketAddress *addr, const char *str, Error **errp)
{
const char *optstr, *h;
char host[65];
char port[33];
int to;
int pos;
char *begin;
memset(addr, 0, sizeof(*addr));
/* parse address */
if (str[0] == ':') {
/* no host given */
host[0] = '\0';
if (sscanf(str, ":%32[^,]%n", port, &pos) != 1) {
error_setg(errp, "error parsing port in address '%s'", str);
return -1;
}
} else if (str[0] == '[') {
/* IPv6 addr */
if (sscanf(str, "[%64[^]]]:%32[^,]%n", host, port, &pos) != 2) {
error_setg(errp, "error parsing IPv6 address '%s'", str);
return -1;
}
} else {
/* hostname or IPv4 addr */
if (sscanf(str, "%64[^:]:%32[^,]%n", host, port, &pos) != 2) {
error_setg(errp, "error parsing address '%s'", str);
return -1;
}
}
addr->host = g_strdup(host);
addr->port = g_strdup(port);
/* parse options */
optstr = str + pos;
h = strstr(optstr, ",to=");
if (h) {
h += 4;
if (sscanf(h, "%d%n", &to, &pos) != 1 ||
(h[pos] != '\0' && h[pos] != ',')) {
error_setg(errp, "error parsing to= argument");
return -1;
}
addr->has_to = true;
addr->to = to;
}
begin = strstr(optstr, ",ipv4");
if (begin) {
if (inet_parse_flag("ipv4", begin + 5, &addr->ipv4, errp) < 0) {
return -1;
}
addr->has_ipv4 = true;
}
begin = strstr(optstr, ",ipv6");
if (begin) {
if (inet_parse_flag("ipv6", begin + 5, &addr->ipv6, errp) < 0) {
return -1;
}
addr->has_ipv6 = true;
}
begin = strstr(optstr, ",keep-alive");
if (begin) {
if (inet_parse_flag("keep-alive", begin + strlen(",keep-alive"),
&addr->keep_alive, errp) < 0)
{
return -1;
}
addr->has_keep_alive = true;
}
#ifdef HAVE_IPPROTO_MPTCP
begin = strstr(optstr, ",mptcp");
if (begin) {
if (inet_parse_flag("mptcp", begin + strlen(",mptcp"),
&addr->mptcp, errp) < 0)
{
return -1;
}
addr->has_mptcp = true;
}
#endif
return 0;
}
#ifdef CONFIG_AF_VSOCK
static bool vsock_parse_vaddr_to_sockaddr(const VsockSocketAddress *vaddr,
struct sockaddr_vm *svm,
Error **errp)
{
uint64_t val;
memset(svm, 0, sizeof(*svm));
svm->svm_family = AF_VSOCK;
if (parse_uint_full(vaddr->cid, 10, &val) < 0 ||
val > UINT32_MAX) {
error_setg(errp, "Failed to parse cid '%s'", vaddr->cid);
return false;
}
svm->svm_cid = val;
if (parse_uint_full(vaddr->port, 10, &val) < 0 ||
val > UINT32_MAX) {
error_setg(errp, "Failed to parse port '%s'", vaddr->port);
return false;
}
svm->svm_port = val;
return true;
}
static int vsock_connect_addr(const VsockSocketAddress *vaddr,
const struct sockaddr_vm *svm, Error **errp)
{
int sock, rc;
sock = qemu_socket(AF_VSOCK, SOCK_STREAM, 0);
if (sock < 0) {
error_setg_errno(errp, errno, "Failed to create socket family %d",
AF_VSOCK);
return -1;
}
/* connect to peer */
do {
rc = 0;
if (connect(sock, (const struct sockaddr *)svm, sizeof(*svm)) < 0) {
rc = -errno;
}
} while (rc == -EINTR);
if (rc < 0) {
error_setg_errno(errp, errno, "Failed to connect to '%s:%s'",
vaddr->cid, vaddr->port);
close(sock);
return -1;
}
return sock;
}
static int vsock_connect_saddr(VsockSocketAddress *vaddr, Error **errp)
{
struct sockaddr_vm svm;
if (!vsock_parse_vaddr_to_sockaddr(vaddr, &svm, errp)) {
return -1;
}
return vsock_connect_addr(vaddr, &svm, errp);
}
static int vsock_listen_saddr(VsockSocketAddress *vaddr,
int num,
Error **errp)
{
struct sockaddr_vm svm;
int slisten;
if (!vsock_parse_vaddr_to_sockaddr(vaddr, &svm, errp)) {
return -1;
}
slisten = qemu_socket(AF_VSOCK, SOCK_STREAM, 0);
if (slisten < 0) {
error_setg_errno(errp, errno, "Failed to create socket");
return -1;
}
if (bind(slisten, (const struct sockaddr *)&svm, sizeof(svm)) != 0) {
error_setg_errno(errp, errno, "Failed to bind socket");
close(slisten);
return -1;
}
if (listen(slisten, num) != 0) {
error_setg_errno(errp, errno, "Failed to listen on socket");
close(slisten);
return -1;
}
return slisten;
}
static int vsock_parse(VsockSocketAddress *addr, const char *str,
Error **errp)
{
char cid[33];
char port[33];
int n;
if (sscanf(str, "%32[^:]:%32[^,]%n", cid, port, &n) != 2) {
error_setg(errp, "error parsing address '%s'", str);
return -1;
}
if (str[n] != '\0') {
error_setg(errp, "trailing characters in address '%s'", str);
return -1;
}
addr->cid = g_strdup(cid);
addr->port = g_strdup(port);
return 0;
}
#else
static void vsock_unsupported(Error **errp)
{
error_setg(errp, "socket family AF_VSOCK unsupported");
}
static int vsock_connect_saddr(VsockSocketAddress *vaddr, Error **errp)
{
vsock_unsupported(errp);
return -1;
}
static int vsock_listen_saddr(VsockSocketAddress *vaddr,
int num,
Error **errp)
{
vsock_unsupported(errp);
return -1;
}
static int vsock_parse(VsockSocketAddress *addr, const char *str,
Error **errp)
{
vsock_unsupported(errp);
return -1;
}
#endif /* CONFIG_AF_VSOCK */
static bool saddr_is_abstract(UnixSocketAddress *saddr)
{
#ifdef CONFIG_LINUX
return saddr->abstract;
#else
return false;
#endif
}
static bool saddr_is_tight(UnixSocketAddress *saddr)
{
#ifdef CONFIG_LINUX
return !saddr->has_tight || saddr->tight;
#else
return false;
#endif
}
static int unix_listen_saddr(UnixSocketAddress *saddr,
int num,
Error **errp)
{
bool abstract = saddr_is_abstract(saddr);
struct sockaddr_un un;
int sock, fd;
char *pathbuf = NULL;
const char *path;
size_t pathlen;
size_t addrlen;
sock = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
if (sock < 0) {
error_setg_errno(errp, errno, "Failed to create Unix socket");
return -1;
}
if (saddr->path[0] || abstract) {
path = saddr->path;
} else {
path = pathbuf = g_strdup_printf("%s/qemu-socket-XXXXXX",
g_get_tmp_dir());
}
pathlen = strlen(path);
if (pathlen > sizeof(un.sun_path) ||
(abstract && pathlen > (sizeof(un.sun_path) - 1))) {
error_setg(errp, "UNIX socket path '%s' is too long", path);
error_append_hint(errp, "Path must be less than %zu bytes\n",
abstract ? sizeof(un.sun_path) - 1 :
sizeof(un.sun_path));
goto err;
}
if (pathbuf != NULL) {
/*
* This dummy fd usage silences the mktemp() insecure warning.
* Using mkstemp() doesn't make things more secure here
* though. bind() complains about existing files, so we have
* to unlink first and thus re-open the race window. The
* worst case possible is bind() failing, i.e. a DoS attack.
*/
fd = mkstemp(pathbuf);
if (fd < 0) {
error_setg_errno(errp, errno,
"Failed to make a temporary socket %s", pathbuf);
goto err;
}
close(fd);
}
if (!abstract && unlink(path) < 0 && errno != ENOENT) {
error_setg_errno(errp, errno,
"Failed to unlink socket %s", path);
goto err;
}
memset(&un, 0, sizeof(un));
un.sun_family = AF_UNIX;
addrlen = sizeof(un);
if (abstract) {
un.sun_path[0] = '\0';
memcpy(&un.sun_path[1], path, pathlen);
if (saddr_is_tight(saddr)) {
addrlen = offsetof(struct sockaddr_un, sun_path) + 1 + pathlen;
}
} else {
memcpy(un.sun_path, path, pathlen);
}
if (bind(sock, (struct sockaddr *) &un, addrlen) < 0) {
error_setg_errno(errp, errno, "Failed to bind socket to %s", path);
goto err;
}
if (listen(sock, num) < 0) {
error_setg_errno(errp, errno, "Failed to listen on socket");
goto err;
}
g_free(pathbuf);
return sock;
err:
g_free(pathbuf);
close(sock);
return -1;
}
static int unix_connect_saddr(UnixSocketAddress *saddr, Error **errp)
{
bool abstract = saddr_is_abstract(saddr);
struct sockaddr_un un;
int sock, rc;
size_t pathlen;
size_t addrlen;
if (saddr->path == NULL) {
error_setg(errp, "unix connect: no path specified");
return -1;
}
sock = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
if (sock < 0) {
error_setg_errno(errp, errno, "Failed to create socket");
return -1;
}
pathlen = strlen(saddr->path);
if (pathlen > sizeof(un.sun_path) ||
(abstract && pathlen > (sizeof(un.sun_path) - 1))) {
error_setg(errp, "UNIX socket path '%s' is too long", saddr->path);
error_append_hint(errp, "Path must be less than %zu bytes\n",
abstract ? sizeof(un.sun_path) - 1 :
sizeof(un.sun_path));
goto err;
}
memset(&un, 0, sizeof(un));
un.sun_family = AF_UNIX;
addrlen = sizeof(un);
if (abstract) {
un.sun_path[0] = '\0';
memcpy(&un.sun_path[1], saddr->path, pathlen);
if (saddr_is_tight(saddr)) {
addrlen = offsetof(struct sockaddr_un, sun_path) + 1 + pathlen;
}
} else {
memcpy(un.sun_path, saddr->path, pathlen);
}
/* connect to peer */
do {
rc = 0;
if (connect(sock, (struct sockaddr *) &un, addrlen) < 0) {
rc = -errno;
}
} while (rc == -EINTR);
if (rc < 0) {
error_setg_errno(errp, -rc, "Failed to connect to '%s'",
saddr->path);
goto err;
}
return sock;
err:
close(sock);
return -1;
}
/* compatibility wrapper */
int unix_listen(const char *str, Error **errp)
{
UnixSocketAddress *saddr;
int sock;
saddr = g_new0(UnixSocketAddress, 1);
saddr->path = g_strdup(str);
sock = unix_listen_saddr(saddr, 1, errp);
qapi_free_UnixSocketAddress(saddr);
return sock;
}
int unix_connect(const char *path, Error **errp)
{
UnixSocketAddress *saddr;
int sock;
saddr = g_new0(UnixSocketAddress, 1);
saddr->path = g_strdup(path);
sock = unix_connect_saddr(saddr, errp);
qapi_free_UnixSocketAddress(saddr);
return sock;
}
char *socket_uri(SocketAddress *addr)
{
switch (addr->type) {
case SOCKET_ADDRESS_TYPE_INET:
return g_strdup_printf("tcp:%s:%s",
addr->u.inet.host,
addr->u.inet.port);
case SOCKET_ADDRESS_TYPE_UNIX:
return g_strdup_printf("unix:%s",
addr->u.q_unix.path);
case SOCKET_ADDRESS_TYPE_FD:
return g_strdup_printf("fd:%s", addr->u.fd.str);
case SOCKET_ADDRESS_TYPE_VSOCK:
return g_strdup_printf("vsock:%s:%s",
addr->u.vsock.cid,
addr->u.vsock.port);
default:
return g_strdup("unknown address type");
}
}
SocketAddress *socket_parse(const char *str, Error **errp)
{
SocketAddress *addr;
addr = g_new0(SocketAddress, 1);
if (strstart(str, "unix:", NULL)) {
if (str[5] == '\0') {
error_setg(errp, "invalid Unix socket address");
goto fail;
} else {
addr->type = SOCKET_ADDRESS_TYPE_UNIX;
addr->u.q_unix.path = g_strdup(str + 5);
}
} else if (strstart(str, "fd:", NULL)) {
if (str[3] == '\0') {
error_setg(errp, "invalid file descriptor address");
goto fail;
} else {
addr->type = SOCKET_ADDRESS_TYPE_FD;
addr->u.fd.str = g_strdup(str + 3);
}
} else if (strstart(str, "vsock:", NULL)) {
addr->type = SOCKET_ADDRESS_TYPE_VSOCK;
if (vsock_parse(&addr->u.vsock, str + strlen("vsock:"), errp)) {
goto fail;
}
} else if (strstart(str, "tcp:", NULL)) {
addr->type = SOCKET_ADDRESS_TYPE_INET;
if (inet_parse(&addr->u.inet, str + strlen("tcp:"), errp)) {
goto fail;
}
} else {
addr->type = SOCKET_ADDRESS_TYPE_INET;
if (inet_parse(&addr->u.inet, str, errp)) {
goto fail;
}
}
return addr;
fail:
qapi_free_SocketAddress(addr);
return NULL;
}
static int socket_get_fd(const char *fdstr, Error **errp)
{
Monitor *cur_mon = monitor_cur();
int fd;
if (cur_mon) {
fd = monitor_get_fd(cur_mon, fdstr, errp);
if (fd < 0) {
return -1;
}
} else {
if (qemu_strtoi(fdstr, NULL, 10, &fd) < 0) {
error_setg_errno(errp, errno,
"Unable to parse FD number %s",
fdstr);
return -1;
}
}
if (!fd_is_socket(fd)) {
error_setg(errp, "File descriptor '%s' is not a socket", fdstr);
close(fd);
return -1;
}
return fd;
}
int socket_address_parse_named_fd(SocketAddress *addr, Error **errp)
{
int fd;
if (addr->type != SOCKET_ADDRESS_TYPE_FD) {
return 0;
}
fd = socket_get_fd(addr->u.fd.str, errp);
if (fd < 0) {
return fd;
}
g_free(addr->u.fd.str);
addr->u.fd.str = g_strdup_printf("%d", fd);
return 0;
}
int socket_connect(SocketAddress *addr, Error **errp)
{
int fd;
switch (addr->type) {
case SOCKET_ADDRESS_TYPE_INET:
fd = inet_connect_saddr(&addr->u.inet, errp);
break;
case SOCKET_ADDRESS_TYPE_UNIX:
fd = unix_connect_saddr(&addr->u.q_unix, errp);
break;
case SOCKET_ADDRESS_TYPE_FD:
fd = socket_get_fd(addr->u.fd.str, errp);
break;
case SOCKET_ADDRESS_TYPE_VSOCK:
fd = vsock_connect_saddr(&addr->u.vsock, errp);
break;
default:
abort();
}
return fd;
}
int socket_listen(SocketAddress *addr, int num, Error **errp)
{
int fd;
trace_socket_listen(num);
switch (addr->type) {
case SOCKET_ADDRESS_TYPE_INET:
fd = inet_listen_saddr(&addr->u.inet, 0, num, errp);
break;
case SOCKET_ADDRESS_TYPE_UNIX:
fd = unix_listen_saddr(&addr->u.q_unix, num, errp);
break;
case SOCKET_ADDRESS_TYPE_FD:
fd = socket_get_fd(addr->u.fd.str, errp);
if (fd < 0) {
return -1;
}
/*
* If the socket is not yet in the listen state, then transition it to
* the listen state now.
*
* If it's already listening then this updates the backlog value as
* requested.
*
* If this socket cannot listen because it's already in another state
* (e.g. unbound or connected) then we'll catch the error here.
*/
if (listen(fd, num) != 0) {
error_setg_errno(errp, errno, "Failed to listen on fd socket");
close(fd);
return -1;
}
break;
case SOCKET_ADDRESS_TYPE_VSOCK:
fd = vsock_listen_saddr(&addr->u.vsock, num, errp);
break;
default:
abort();
}
return fd;
}
void socket_listen_cleanup(int fd, Error **errp)
{
SocketAddress *addr;
addr = socket_local_address(fd, errp);
if (!addr) {
return;
}
if (addr->type == SOCKET_ADDRESS_TYPE_UNIX
&& addr->u.q_unix.path) {
if (unlink(addr->u.q_unix.path) < 0 && errno != ENOENT) {
error_setg_errno(errp, errno,
"Failed to unlink socket %s",
addr->u.q_unix.path);
}
}
qapi_free_SocketAddress(addr);
}
int socket_dgram(SocketAddress *remote, SocketAddress *local, Error **errp)
{
int fd;
/*
* TODO SOCKET_ADDRESS_TYPE_FD when fd is AF_INET or AF_INET6
* (although other address families can do SOCK_DGRAM, too)
*/
switch (remote->type) {
case SOCKET_ADDRESS_TYPE_INET:
fd = inet_dgram_saddr(&remote->u.inet,
local ? &local->u.inet : NULL, errp);
break;
default:
error_setg(errp, "socket type unsupported for datagram");
fd = -1;
}
return fd;
}
static SocketAddress *
socket_sockaddr_to_address_inet(struct sockaddr_storage *sa,
socklen_t salen,
Error **errp)
{
char host[NI_MAXHOST];
char serv[NI_MAXSERV];
SocketAddress *addr;
InetSocketAddress *inet;
int ret;
ret = getnameinfo((struct sockaddr *)sa, salen,
host, sizeof(host),
serv, sizeof(serv),
NI_NUMERICHOST | NI_NUMERICSERV);
if (ret != 0) {
error_setg(errp, "Cannot format numeric socket address: %s",
gai_strerror(ret));
return NULL;
}
addr = g_new0(SocketAddress, 1);
addr->type = SOCKET_ADDRESS_TYPE_INET;
inet = &addr->u.inet;
inet->host = g_strdup(host);
inet->port = g_strdup(serv);
if (sa->ss_family == AF_INET) {
inet->has_ipv4 = inet->ipv4 = true;
} else {
inet->has_ipv6 = inet->ipv6 = true;
}
return addr;
}
static SocketAddress *
socket_sockaddr_to_address_unix(struct sockaddr_storage *sa,
socklen_t salen,
Error **errp)
{
SocketAddress *addr;
struct sockaddr_un *su = (struct sockaddr_un *)sa;
addr = g_new0(SocketAddress, 1);
addr->type = SOCKET_ADDRESS_TYPE_UNIX;
salen -= offsetof(struct sockaddr_un, sun_path);
#ifdef CONFIG_LINUX
if (salen > 0 && !su->sun_path[0]) {
/* Linux abstract socket */
addr->u.q_unix.path = g_strndup(su->sun_path + 1, salen - 1);
addr->u.q_unix.has_abstract = true;
addr->u.q_unix.abstract = true;
addr->u.q_unix.has_tight = true;
addr->u.q_unix.tight = salen < sizeof(su->sun_path);
return addr;
}
#endif
addr->u.q_unix.path = g_strndup(su->sun_path, salen);
return addr;
}
#ifdef CONFIG_AF_VSOCK
static SocketAddress *
socket_sockaddr_to_address_vsock(struct sockaddr_storage *sa,
socklen_t salen,
Error **errp)
{
SocketAddress *addr;
VsockSocketAddress *vaddr;
struct sockaddr_vm *svm = (struct sockaddr_vm *)sa;
addr = g_new0(SocketAddress, 1);
addr->type = SOCKET_ADDRESS_TYPE_VSOCK;
vaddr = &addr->u.vsock;
vaddr->cid = g_strdup_printf("%u", svm->svm_cid);
vaddr->port = g_strdup_printf("%u", svm->svm_port);
return addr;
}
#endif /* CONFIG_AF_VSOCK */
SocketAddress *
socket_sockaddr_to_address(struct sockaddr_storage *sa,
socklen_t salen,
Error **errp)
{
switch (sa->ss_family) {
case AF_INET:
case AF_INET6:
return socket_sockaddr_to_address_inet(sa, salen, errp);
case AF_UNIX:
return socket_sockaddr_to_address_unix(sa, salen, errp);
#ifdef CONFIG_AF_VSOCK
case AF_VSOCK:
return socket_sockaddr_to_address_vsock(sa, salen, errp);
#endif
default:
error_setg(errp, "socket family %d unsupported",
sa->ss_family);
return NULL;
}
return 0;
}
SocketAddress *socket_local_address(int fd, Error **errp)
{
struct sockaddr_storage ss;
socklen_t sslen = sizeof(ss);
if (getsockname(fd, (struct sockaddr *)&ss, &sslen) < 0) {
error_setg_errno(errp, errno, "%s",
"Unable to query local socket address");
return NULL;
}
return socket_sockaddr_to_address(&ss, sslen, errp);
}
SocketAddress *socket_address_flatten(SocketAddressLegacy *addr_legacy)
{
SocketAddress *addr;
if (!addr_legacy) {
return NULL;
}
addr = g_new(SocketAddress, 1);
switch (addr_legacy->type) {
case SOCKET_ADDRESS_TYPE_INET:
addr->type = SOCKET_ADDRESS_TYPE_INET;
QAPI_CLONE_MEMBERS(InetSocketAddress, &addr->u.inet,
addr_legacy->u.inet.data);
break;
case SOCKET_ADDRESS_TYPE_UNIX:
addr->type = SOCKET_ADDRESS_TYPE_UNIX;
QAPI_CLONE_MEMBERS(UnixSocketAddress, &addr->u.q_unix,
addr_legacy->u.q_unix.data);
break;
case SOCKET_ADDRESS_TYPE_VSOCK:
addr->type = SOCKET_ADDRESS_TYPE_VSOCK;
QAPI_CLONE_MEMBERS(VsockSocketAddress, &addr->u.vsock,
addr_legacy->u.vsock.data);
break;
case SOCKET_ADDRESS_TYPE_FD:
addr->type = SOCKET_ADDRESS_TYPE_FD;
QAPI_CLONE_MEMBERS(FdSocketAddress, &addr->u.fd,
addr_legacy->u.fd.data);
break;
default:
abort();
}
return addr;
}
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