2 This file is part of systemd.
4 Copyright 2010 Lennart Poettering
6 systemd is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
11 systemd is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public License
17 along with systemd; If not, see <http://www.gnu.org/licenses/>.
20 #include <arpa/inet.h>
25 #include <netinet/ip.h>
34 #include "alloc-util.h"
37 #include "format-util.h"
41 #include "parse-util.h"
42 #include "path-util.h"
43 #include "socket-util.h"
44 #include "string-table.h"
45 #include "string-util.h"
47 #include "user-util.h"
51 int socket_address_parse(SocketAddress
*a
, const char *s
) {
60 a
->type
= SOCK_STREAM
;
63 /* IPv6 in [x:.....:z]:p notation */
69 n
= strndupa(s
+1, e
-s
-1);
72 if (inet_pton(AF_INET6
, n
, &a
->sockaddr
.in6
.sin6_addr
) <= 0)
73 return errno
> 0 ? -errno
: -EINVAL
;
84 if (u
<= 0 || u
> 0xFFFF)
87 a
->sockaddr
.in6
.sin6_family
= AF_INET6
;
88 a
->sockaddr
.in6
.sin6_port
= htobe16((uint16_t)u
);
89 a
->size
= sizeof(struct sockaddr_in6
);
91 } else if (*s
== '/') {
97 if (l
>= sizeof(a
->sockaddr
.un
.sun_path
))
100 a
->sockaddr
.un
.sun_family
= AF_UNIX
;
101 memcpy(a
->sockaddr
.un
.sun_path
, s
, l
);
102 a
->size
= offsetof(struct sockaddr_un
, sun_path
) + l
+ 1;
104 } else if (*s
== '@') {
105 /* Abstract AF_UNIX socket */
109 if (l
>= sizeof(a
->sockaddr
.un
.sun_path
) - 1)
112 a
->sockaddr
.un
.sun_family
= AF_UNIX
;
113 memcpy(a
->sockaddr
.un
.sun_path
+1, s
+1, l
);
114 a
->size
= offsetof(struct sockaddr_un
, sun_path
) + 1 + l
;
119 r
= safe_atou(e
+1, &u
);
123 if (u
<= 0 || u
> 0xFFFF)
126 n
= strndupa(s
, e
-s
);
128 /* IPv4 in w.x.y.z:p notation? */
129 r
= inet_pton(AF_INET
, n
, &a
->sockaddr
.in
.sin_addr
);
134 /* Gotcha, it's a traditional IPv4 address */
135 a
->sockaddr
.in
.sin_family
= AF_INET
;
136 a
->sockaddr
.in
.sin_port
= htobe16((uint16_t)u
);
137 a
->size
= sizeof(struct sockaddr_in
);
141 if (strlen(n
) > IF_NAMESIZE
-1)
144 /* Uh, our last resort, an interface name */
145 idx
= if_nametoindex(n
);
149 a
->sockaddr
.in6
.sin6_family
= AF_INET6
;
150 a
->sockaddr
.in6
.sin6_port
= htobe16((uint16_t)u
);
151 a
->sockaddr
.in6
.sin6_scope_id
= idx
;
152 a
->sockaddr
.in6
.sin6_addr
= in6addr_any
;
153 a
->size
= sizeof(struct sockaddr_in6
);
158 r
= safe_atou(s
, &u
);
162 if (u
<= 0 || u
> 0xFFFF)
165 if (socket_ipv6_is_supported()) {
166 a
->sockaddr
.in6
.sin6_family
= AF_INET6
;
167 a
->sockaddr
.in6
.sin6_port
= htobe16((uint16_t)u
);
168 a
->sockaddr
.in6
.sin6_addr
= in6addr_any
;
169 a
->size
= sizeof(struct sockaddr_in6
);
171 a
->sockaddr
.in
.sin_family
= AF_INET
;
172 a
->sockaddr
.in
.sin_port
= htobe16((uint16_t)u
);
173 a
->sockaddr
.in
.sin_addr
.s_addr
= INADDR_ANY
;
174 a
->size
= sizeof(struct sockaddr_in
);
182 int socket_address_parse_and_warn(SocketAddress
*a
, const char *s
) {
186 /* Similar to socket_address_parse() but warns for IPv6 sockets when we don't support them. */
188 r
= socket_address_parse(&b
, s
);
192 if (!socket_ipv6_is_supported() && b
.sockaddr
.sa
.sa_family
== AF_INET6
) {
193 log_warning("Binding to IPv6 address not available since kernel does not support IPv6.");
194 return -EAFNOSUPPORT
;
201 int socket_address_parse_netlink(SocketAddress
*a
, const char *s
) {
204 _cleanup_free_
char *sfamily
= NULL
;
212 if (sscanf(s
, "%ms %u", &sfamily
, &group
) < 1)
213 return errno
> 0 ? -errno
: -EINVAL
;
215 family
= netlink_family_from_string(sfamily
);
219 a
->sockaddr
.nl
.nl_family
= AF_NETLINK
;
220 a
->sockaddr
.nl
.nl_groups
= group
;
223 a
->size
= sizeof(struct sockaddr_nl
);
224 a
->protocol
= family
;
229 int socket_address_verify(const SocketAddress
*a
) {
232 switch (socket_address_family(a
)) {
235 if (a
->size
!= sizeof(struct sockaddr_in
))
238 if (a
->sockaddr
.in
.sin_port
== 0)
241 if (a
->type
!= SOCK_STREAM
&& a
->type
!= SOCK_DGRAM
)
247 if (a
->size
!= sizeof(struct sockaddr_in6
))
250 if (a
->sockaddr
.in6
.sin6_port
== 0)
253 if (a
->type
!= SOCK_STREAM
&& a
->type
!= SOCK_DGRAM
)
259 if (a
->size
< offsetof(struct sockaddr_un
, sun_path
))
262 if (a
->size
> offsetof(struct sockaddr_un
, sun_path
)) {
264 if (a
->sockaddr
.un
.sun_path
[0] != 0) {
268 e
= memchr(a
->sockaddr
.un
.sun_path
, 0, sizeof(a
->sockaddr
.un
.sun_path
));
272 if (a
->size
!= offsetof(struct sockaddr_un
, sun_path
) + (e
- a
->sockaddr
.un
.sun_path
) + 1)
277 if (a
->type
!= SOCK_STREAM
&& a
->type
!= SOCK_DGRAM
&& a
->type
!= SOCK_SEQPACKET
)
284 if (a
->size
!= sizeof(struct sockaddr_nl
))
287 if (a
->type
!= SOCK_RAW
&& a
->type
!= SOCK_DGRAM
)
293 return -EAFNOSUPPORT
;
297 int socket_address_print(const SocketAddress
*a
, char **ret
) {
303 r
= socket_address_verify(a
);
307 if (socket_address_family(a
) == AF_NETLINK
) {
308 _cleanup_free_
char *sfamily
= NULL
;
310 r
= netlink_family_to_string_alloc(a
->protocol
, &sfamily
);
314 r
= asprintf(ret
, "%s %u", sfamily
, a
->sockaddr
.nl
.nl_groups
);
321 return sockaddr_pretty(&a
->sockaddr
.sa
, a
->size
, false, true, ret
);
324 bool socket_address_can_accept(const SocketAddress
*a
) {
328 a
->type
== SOCK_STREAM
||
329 a
->type
== SOCK_SEQPACKET
;
332 bool socket_address_equal(const SocketAddress
*a
, const SocketAddress
*b
) {
336 /* Invalid addresses are unequal to all */
337 if (socket_address_verify(a
) < 0 ||
338 socket_address_verify(b
) < 0)
341 if (a
->type
!= b
->type
)
344 if (socket_address_family(a
) != socket_address_family(b
))
347 switch (socket_address_family(a
)) {
350 if (a
->sockaddr
.in
.sin_addr
.s_addr
!= b
->sockaddr
.in
.sin_addr
.s_addr
)
353 if (a
->sockaddr
.in
.sin_port
!= b
->sockaddr
.in
.sin_port
)
359 if (memcmp(&a
->sockaddr
.in6
.sin6_addr
, &b
->sockaddr
.in6
.sin6_addr
, sizeof(a
->sockaddr
.in6
.sin6_addr
)) != 0)
362 if (a
->sockaddr
.in6
.sin6_port
!= b
->sockaddr
.in6
.sin6_port
)
368 if (a
->size
<= offsetof(struct sockaddr_un
, sun_path
) ||
369 b
->size
<= offsetof(struct sockaddr_un
, sun_path
))
372 if ((a
->sockaddr
.un
.sun_path
[0] == 0) != (b
->sockaddr
.un
.sun_path
[0] == 0))
375 if (a
->sockaddr
.un
.sun_path
[0]) {
376 if (!path_equal_or_files_same(a
->sockaddr
.un
.sun_path
, b
->sockaddr
.un
.sun_path
))
379 if (a
->size
!= b
->size
)
382 if (memcmp(a
->sockaddr
.un
.sun_path
, b
->sockaddr
.un
.sun_path
, a
->size
) != 0)
389 if (a
->protocol
!= b
->protocol
)
392 if (a
->sockaddr
.nl
.nl_groups
!= b
->sockaddr
.nl
.nl_groups
)
398 /* Cannot compare, so we assume the addresses are different */
405 bool socket_address_is(const SocketAddress
*a
, const char *s
, int type
) {
406 struct SocketAddress b
;
411 if (socket_address_parse(&b
, s
) < 0)
416 return socket_address_equal(a
, &b
);
419 bool socket_address_is_netlink(const SocketAddress
*a
, const char *s
) {
420 struct SocketAddress b
;
425 if (socket_address_parse_netlink(&b
, s
) < 0)
428 return socket_address_equal(a
, &b
);
431 const char* socket_address_get_path(const SocketAddress
*a
) {
434 if (socket_address_family(a
) != AF_UNIX
)
437 if (a
->sockaddr
.un
.sun_path
[0] == 0)
440 return a
->sockaddr
.un
.sun_path
;
443 bool socket_ipv6_is_supported(void) {
444 if (access("/proc/net/if_inet6", F_OK
) != 0)
450 bool socket_address_matches_fd(const SocketAddress
*a
, int fd
) {
457 b
.size
= sizeof(b
.sockaddr
);
458 if (getsockname(fd
, &b
.sockaddr
.sa
, &b
.size
) < 0)
461 if (b
.sockaddr
.sa
.sa_family
!= a
->sockaddr
.sa
.sa_family
)
464 solen
= sizeof(b
.type
);
465 if (getsockopt(fd
, SOL_SOCKET
, SO_TYPE
, &b
.type
, &solen
) < 0)
468 if (b
.type
!= a
->type
)
471 if (a
->protocol
!= 0) {
472 solen
= sizeof(b
.protocol
);
473 if (getsockopt(fd
, SOL_SOCKET
, SO_PROTOCOL
, &b
.protocol
, &solen
) < 0)
476 if (b
.protocol
!= a
->protocol
)
480 return socket_address_equal(a
, &b
);
483 int sockaddr_port(const struct sockaddr
*_sa
, unsigned *port
) {
484 union sockaddr_union
*sa
= (union sockaddr_union
*) _sa
;
488 if (!IN_SET(sa
->sa
.sa_family
, AF_INET
, AF_INET6
))
489 return -EAFNOSUPPORT
;
491 *port
= be16toh(sa
->sa
.sa_family
== AF_INET6
? sa
->in6
.sin6_port
: sa
->in
.sin_port
);
495 int sockaddr_pretty(const struct sockaddr
*_sa
, socklen_t salen
, bool translate_ipv6
, bool include_port
, char **ret
) {
496 union sockaddr_union
*sa
= (union sockaddr_union
*) _sa
;
501 assert(salen
>= sizeof(sa
->sa
.sa_family
));
503 switch (sa
->sa
.sa_family
) {
508 a
= be32toh(sa
->in
.sin_addr
.s_addr
);
513 a
>> 24, (a
>> 16) & 0xFF, (a
>> 8) & 0xFF, a
& 0xFF,
514 be16toh(sa
->in
.sin_port
));
518 a
>> 24, (a
>> 16) & 0xFF, (a
>> 8) & 0xFF, a
& 0xFF);
525 static const unsigned char ipv4_prefix
[] = {
526 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF
529 if (translate_ipv6
&&
530 memcmp(&sa
->in6
.sin6_addr
, ipv4_prefix
, sizeof(ipv4_prefix
)) == 0) {
531 const uint8_t *a
= sa
->in6
.sin6_addr
.s6_addr
+12;
535 a
[0], a
[1], a
[2], a
[3],
536 be16toh(sa
->in6
.sin6_port
));
540 a
[0], a
[1], a
[2], a
[3]);
544 char a
[INET6_ADDRSTRLEN
];
546 inet_ntop(AF_INET6
, &sa
->in6
.sin6_addr
, a
, sizeof(a
));
552 be16toh(sa
->in6
.sin6_port
));
566 if (salen
<= offsetof(struct sockaddr_un
, sun_path
)) {
567 p
= strdup("<unnamed>");
571 } else if (sa
->un
.sun_path
[0] == 0) {
574 /* FIXME: We assume we can print the
575 * socket path here and that it hasn't
576 * more than one NUL byte. That is
577 * actually an invalid assumption */
579 p
= new(char, sizeof(sa
->un
.sun_path
)+1);
584 memcpy(p
+1, sa
->un
.sun_path
+1, sizeof(sa
->un
.sun_path
)-1);
585 p
[sizeof(sa
->un
.sun_path
)] = 0;
588 p
= strndup(sa
->un
.sun_path
, sizeof(sa
->un
.sun_path
));
604 int getpeername_pretty(int fd
, bool include_port
, char **ret
) {
605 union sockaddr_union sa
;
606 socklen_t salen
= sizeof(sa
);
612 if (getpeername(fd
, &sa
.sa
, &salen
) < 0)
615 if (sa
.sa
.sa_family
== AF_UNIX
) {
616 struct ucred ucred
= {};
618 /* UNIX connection sockets are anonymous, so let's use
619 * PID/UID as pretty credentials instead */
621 r
= getpeercred(fd
, &ucred
);
625 if (asprintf(ret
, "PID "PID_FMT
"/UID "UID_FMT
, ucred
.pid
, ucred
.uid
) < 0)
631 /* For remote sockets we translate IPv6 addresses back to IPv4
632 * if applicable, since that's nicer. */
634 return sockaddr_pretty(&sa
.sa
, salen
, true, include_port
, ret
);
637 int getsockname_pretty(int fd
, char **ret
) {
638 union sockaddr_union sa
;
639 socklen_t salen
= sizeof(sa
);
644 if (getsockname(fd
, &sa
.sa
, &salen
) < 0)
647 /* For local sockets we do not translate IPv6 addresses back
648 * to IPv6 if applicable, since this is usually used for
649 * listening sockets where the difference between IPv4 and
652 return sockaddr_pretty(&sa
.sa
, salen
, false, true, ret
);
655 int socknameinfo_pretty(union sockaddr_union
*sa
, socklen_t salen
, char **_ret
) {
657 char host
[NI_MAXHOST
], *ret
;
661 r
= getnameinfo(&sa
->sa
, salen
, host
, sizeof(host
), NULL
, 0,
662 NI_IDN
|NI_IDN_USE_STD3_ASCII_RULES
);
664 int saved_errno
= errno
;
666 r
= sockaddr_pretty(&sa
->sa
, salen
, true, true, &ret
);
670 log_debug_errno(saved_errno
, "getnameinfo(%s) failed: %m", ret
);
681 int getnameinfo_pretty(int fd
, char **ret
) {
682 union sockaddr_union sa
;
683 socklen_t salen
= sizeof(sa
);
688 if (getsockname(fd
, &sa
.sa
, &salen
) < 0)
691 return socknameinfo_pretty(&sa
, salen
, ret
);
694 int socket_address_unlink(SocketAddress
*a
) {
697 if (socket_address_family(a
) != AF_UNIX
)
700 if (a
->sockaddr
.un
.sun_path
[0] == 0)
703 if (unlink(a
->sockaddr
.un
.sun_path
) < 0)
709 static const char* const netlink_family_table
[] = {
710 [NETLINK_ROUTE
] = "route",
711 [NETLINK_FIREWALL
] = "firewall",
712 [NETLINK_INET_DIAG
] = "inet-diag",
713 [NETLINK_NFLOG
] = "nflog",
714 [NETLINK_XFRM
] = "xfrm",
715 [NETLINK_SELINUX
] = "selinux",
716 [NETLINK_ISCSI
] = "iscsi",
717 [NETLINK_AUDIT
] = "audit",
718 [NETLINK_FIB_LOOKUP
] = "fib-lookup",
719 [NETLINK_CONNECTOR
] = "connector",
720 [NETLINK_NETFILTER
] = "netfilter",
721 [NETLINK_IP6_FW
] = "ip6-fw",
722 [NETLINK_DNRTMSG
] = "dnrtmsg",
723 [NETLINK_KOBJECT_UEVENT
] = "kobject-uevent",
724 [NETLINK_GENERIC
] = "generic",
725 [NETLINK_SCSITRANSPORT
] = "scsitransport",
726 [NETLINK_ECRYPTFS
] = "ecryptfs"
729 DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(netlink_family
, int, INT_MAX
);
731 static const char* const socket_address_bind_ipv6_only_table
[_SOCKET_ADDRESS_BIND_IPV6_ONLY_MAX
] = {
732 [SOCKET_ADDRESS_DEFAULT
] = "default",
733 [SOCKET_ADDRESS_BOTH
] = "both",
734 [SOCKET_ADDRESS_IPV6_ONLY
] = "ipv6-only"
737 DEFINE_STRING_TABLE_LOOKUP(socket_address_bind_ipv6_only
, SocketAddressBindIPv6Only
);
739 bool sockaddr_equal(const union sockaddr_union
*a
, const union sockaddr_union
*b
) {
743 if (a
->sa
.sa_family
!= b
->sa
.sa_family
)
746 if (a
->sa
.sa_family
== AF_INET
)
747 return a
->in
.sin_addr
.s_addr
== b
->in
.sin_addr
.s_addr
;
749 if (a
->sa
.sa_family
== AF_INET6
)
750 return memcmp(&a
->in6
.sin6_addr
, &b
->in6
.sin6_addr
, sizeof(a
->in6
.sin6_addr
)) == 0;
755 int fd_inc_sndbuf(int fd
, size_t n
) {
757 socklen_t l
= sizeof(value
);
759 r
= getsockopt(fd
, SOL_SOCKET
, SO_SNDBUF
, &value
, &l
);
760 if (r
>= 0 && l
== sizeof(value
) && (size_t) value
>= n
*2)
763 /* If we have the privileges we will ignore the kernel limit. */
766 if (setsockopt(fd
, SOL_SOCKET
, SO_SNDBUFFORCE
, &value
, sizeof(value
)) < 0)
767 if (setsockopt(fd
, SOL_SOCKET
, SO_SNDBUF
, &value
, sizeof(value
)) < 0)
773 int fd_inc_rcvbuf(int fd
, size_t n
) {
775 socklen_t l
= sizeof(value
);
777 r
= getsockopt(fd
, SOL_SOCKET
, SO_RCVBUF
, &value
, &l
);
778 if (r
>= 0 && l
== sizeof(value
) && (size_t) value
>= n
*2)
781 /* If we have the privileges we will ignore the kernel limit. */
784 if (setsockopt(fd
, SOL_SOCKET
, SO_RCVBUFFORCE
, &value
, sizeof(value
)) < 0)
785 if (setsockopt(fd
, SOL_SOCKET
, SO_RCVBUF
, &value
, sizeof(value
)) < 0)
790 static const char* const ip_tos_table
[] = {
791 [IPTOS_LOWDELAY
] = "low-delay",
792 [IPTOS_THROUGHPUT
] = "throughput",
793 [IPTOS_RELIABILITY
] = "reliability",
794 [IPTOS_LOWCOST
] = "low-cost",
797 DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(ip_tos
, int, 0xff);
799 bool ifname_valid(const char *p
) {
802 /* Checks whether a network interface name is valid. This is inspired by dev_valid_name() in the kernel sources
803 * but slightly stricter, as we only allow non-control, non-space ASCII characters in the interface name. We
804 * also don't permit names that only container numbers, to avoid confusion with numeric interface indexes. */
809 if (strlen(p
) >= IFNAMSIZ
)
812 if (STR_IN_SET(p
, ".", ".."))
816 if ((unsigned char) *p
>= 127U)
819 if ((unsigned char) *p
<= 32U)
822 if (*p
== ':' || *p
== '/')
825 numeric
= numeric
&& (*p
>= '0' && *p
<= '9');
835 int getpeercred(int fd
, struct ucred
*ucred
) {
836 socklen_t n
= sizeof(struct ucred
);
843 r
= getsockopt(fd
, SOL_SOCKET
, SO_PEERCRED
, &u
, &n
);
847 if (n
!= sizeof(struct ucred
))
850 /* Check if the data is actually useful and not suppressed due
851 * to namespacing issues */
854 if (u
.uid
== UID_INVALID
)
856 if (u
.gid
== GID_INVALID
)
863 int getpeersec(int fd
, char **ret
) {
875 r
= getsockopt(fd
, SOL_SOCKET
, SO_PEERSEC
, s
, &n
);
886 r
= getsockopt(fd
, SOL_SOCKET
, SO_PEERSEC
, s
, &n
);
905 const struct sockaddr
*sa
, socklen_t len
,
909 struct cmsghdr cmsghdr
;
910 uint8_t buf
[CMSG_SPACE(sizeof(int))];
913 .msg_name
= (struct sockaddr
*) sa
,
915 .msg_control
= &control
,
916 .msg_controllen
= sizeof(control
),
918 struct cmsghdr
*cmsg
;
920 assert(transport_fd
>= 0);
923 cmsg
= CMSG_FIRSTHDR(&mh
);
924 cmsg
->cmsg_level
= SOL_SOCKET
;
925 cmsg
->cmsg_type
= SCM_RIGHTS
;
926 cmsg
->cmsg_len
= CMSG_LEN(sizeof(int));
927 memcpy(CMSG_DATA(cmsg
), &fd
, sizeof(int));
929 mh
.msg_controllen
= CMSG_SPACE(sizeof(int));
930 if (sendmsg(transport_fd
, &mh
, MSG_NOSIGNAL
| flags
) < 0)
936 int receive_one_fd(int transport_fd
, int flags
) {
938 struct cmsghdr cmsghdr
;
939 uint8_t buf
[CMSG_SPACE(sizeof(int))];
942 .msg_control
= &control
,
943 .msg_controllen
= sizeof(control
),
945 struct cmsghdr
*cmsg
, *found
= NULL
;
947 assert(transport_fd
>= 0);
950 * Receive a single FD via @transport_fd. We don't care for
951 * the transport-type. We retrieve a single FD at most, so for
952 * packet-based transports, the caller must ensure to send
953 * only a single FD per packet. This is best used in
954 * combination with send_one_fd().
957 if (recvmsg(transport_fd
, &mh
, MSG_NOSIGNAL
| MSG_CMSG_CLOEXEC
| flags
) < 0)
960 CMSG_FOREACH(cmsg
, &mh
) {
961 if (cmsg
->cmsg_level
== SOL_SOCKET
&&
962 cmsg
->cmsg_type
== SCM_RIGHTS
&&
963 cmsg
->cmsg_len
== CMSG_LEN(sizeof(int))) {
975 return *(int*) CMSG_DATA(found
);
978 ssize_t
next_datagram_size_fd(int fd
) {
982 /* This is a bit like FIONREAD/SIOCINQ, however a bit more powerful. The difference being: recv(MSG_PEEK) will
983 * actually cause the next datagram in the queue to be validated regarding checksums, which FIONREAD doesn't
984 * do. This difference is actually of major importance as we need to be sure that the size returned here
985 * actually matches what we will read with recvmsg() next, as otherwise we might end up allocating a buffer of
988 l
= recv(fd
, NULL
, 0, MSG_PEEK
|MSG_TRUNC
);
990 if (errno
== EOPNOTSUPP
|| errno
== EFAULT
)
1003 /* Some sockets (AF_PACKET) do not support null-sized recv() with MSG_TRUNC set, let's fall back to FIONREAD
1004 * for them. Checksums don't matter for raw sockets anyway, hence this should be fine. */
1006 if (ioctl(fd
, FIONREAD
, &k
) < 0)
1012 int flush_accept(int fd
) {
1014 struct pollfd pollfd
= {
1021 /* Similar to flush_fd() but flushes all incoming connection by accepting them and immediately closing them. */
1026 r
= poll(&pollfd
, 1, 0);
1036 cfd
= accept4(fd
, NULL
, NULL
, SOCK_NONBLOCK
|SOCK_CLOEXEC
);
1041 if (errno
== EAGAIN
)
1051 struct cmsghdr
* cmsg_find(struct msghdr
*mh
, int level
, int type
, socklen_t length
) {
1052 struct cmsghdr
*cmsg
;
1056 CMSG_FOREACH(cmsg
, mh
)
1057 if (cmsg
->cmsg_level
== level
&&
1058 cmsg
->cmsg_type
== type
&&
1059 (length
== (socklen_t
) -1 || length
== cmsg
->cmsg_len
))
1065 int socket_ioctl_fd(void) {
1068 /* Create a socket to invoke the various network interface ioctl()s on. Traditionally only AF_INET was good for
1069 * that. Since kernel 4.6 AF_NETLINK works for this too. We first try to use AF_INET hence, but if that's not
1070 * available (for example, because it is made unavailable via SECCOMP or such), we'll fall back to the more
1071 * generic AF_NETLINK. */
1073 fd
= socket(AF_INET
, SOCK_DGRAM
|SOCK_CLOEXEC
, 0);
1075 fd
= socket(AF_NETLINK
, SOCK_RAW
|SOCK_CLOEXEC
, NETLINK_GENERIC
);