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2 * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
18 #include "socket-util.h"
19 #include <arpa/inet.h>
29 #include <sys/resource.h>
30 #include <sys/socket.h>
34 #include "dynamic-string.h"
35 #include "fatal-signal.h"
39 #if AF_PACKET && __linux__
40 #include <linux/if_packet.h>
43 #include "netlink-protocol.h"
44 #include "netlink-socket.h"
47 VLOG_DEFINE_THIS_MODULE(socket_util
);
49 /* #ifdefs make it a pain to maintain code: you have to try to build both ways.
50 * Thus, this file compiles all of the code regardless of the target, by
51 * writing "if (LINUX)" instead of "#ifdef __linux__". */
62 /* Sets 'fd' to non-blocking mode. Returns 0 if successful, otherwise a
63 * positive errno value. */
65 set_nonblocking(int fd
)
67 int flags
= fcntl(fd
, F_GETFL
, 0);
69 if (fcntl(fd
, F_SETFL
, flags
| O_NONBLOCK
) != -1) {
72 VLOG_ERR("fcntl(F_SETFL) failed: %s", strerror(errno
));
76 VLOG_ERR("fcntl(F_GETFL) failed: %s", strerror(errno
));
82 rlim_is_finite(rlim_t limit
)
84 if (limit
== RLIM_INFINITY
) {
88 #ifdef RLIM_SAVED_CUR /* FreeBSD 8.0 lacks RLIM_SAVED_CUR. */
89 if (limit
== RLIM_SAVED_CUR
) {
94 #ifdef RLIM_SAVED_MAX /* FreeBSD 8.0 lacks RLIM_SAVED_MAX. */
95 if (limit
== RLIM_SAVED_MAX
) {
103 /* Returns the maximum valid FD value, plus 1. */
107 static int max_fds
= -1;
110 if (!getrlimit(RLIMIT_NOFILE
, &r
) && rlim_is_finite(r
.rlim_cur
)) {
111 max_fds
= r
.rlim_cur
;
113 VLOG_WARN("failed to obtain fd limit, defaulting to 1024");
120 /* Translates 'host_name', which must be a string representation of an IP
121 * address, into a numeric IP address in '*addr'. Returns 0 if successful,
122 * otherwise a positive errno value. */
124 lookup_ip(const char *host_name
, struct in_addr
*addr
)
126 if (!inet_aton(host_name
, addr
)) {
127 static struct vlog_rate_limit rl
= VLOG_RATE_LIMIT_INIT(1, 5);
128 VLOG_ERR_RL(&rl
, "\"%s\" is not a valid IP address", host_name
);
134 /* Translates 'host_name', which must be a string representation of an IPv6
135 * address, into a numeric IPv6 address in '*addr'. Returns 0 if successful,
136 * otherwise a positive errno value. */
138 lookup_ipv6(const char *host_name
, struct in6_addr
*addr
)
140 if (inet_pton(AF_INET6
, host_name
, addr
) != 1) {
141 static struct vlog_rate_limit rl
= VLOG_RATE_LIMIT_INIT(1, 5);
142 VLOG_ERR_RL(&rl
, "\"%s\" is not a valid IPv6 address", host_name
);
148 /* Translates 'host_name', which must be a host name or a string representation
149 * of an IP address, into a numeric IP address in '*addr'. Returns 0 if
150 * successful, otherwise a positive errno value.
152 * Most Open vSwitch code should not use this because it causes deadlocks:
153 * gethostbyname() sends out a DNS request but that starts a new flow for which
154 * OVS must set up a flow, but it can't because it's waiting for a DNS reply.
155 * The synchronous lookup also delays other activty. (Of course we can solve
156 * this but it doesn't seem worthwhile quite yet.) */
158 lookup_hostname(const char *host_name
, struct in_addr
*addr
)
162 if (inet_aton(host_name
, addr
)) {
166 h
= gethostbyname(host_name
);
168 *addr
= *(struct in_addr
*) h
->h_addr
;
172 return (h_errno
== HOST_NOT_FOUND
? ENOENT
173 : h_errno
== TRY_AGAIN
? EAGAIN
174 : h_errno
== NO_RECOVERY
? EIO
175 : h_errno
== NO_ADDRESS
? ENXIO
179 /* Returns the error condition associated with socket 'fd' and resets the
180 * socket's error status. */
182 get_socket_error(int fd
)
185 socklen_t len
= sizeof(error
);
186 if (getsockopt(fd
, SOL_SOCKET
, SO_ERROR
, &error
, &len
) < 0) {
187 static struct vlog_rate_limit rl
= VLOG_RATE_LIMIT_INIT(5, 10);
189 VLOG_ERR_RL(&rl
, "getsockopt(SO_ERROR): %s", strerror(error
));
195 check_connection_completion(int fd
)
201 pfd
.events
= POLLOUT
;
203 retval
= poll(&pfd
, 1, 0);
204 } while (retval
< 0 && errno
== EINTR
);
206 return get_socket_error(fd
);
207 } else if (retval
< 0) {
208 static struct vlog_rate_limit rl
= VLOG_RATE_LIMIT_INIT(5, 10);
209 VLOG_ERR_RL(&rl
, "poll: %s", strerror(errno
));
216 /* Drain all the data currently in the receive queue of a datagram socket (and
217 * possibly additional data). There is no way to know how many packets are in
218 * the receive queue, but we do know that the total number of bytes queued does
219 * not exceed the receive buffer size, so we pull packets until none are left
220 * or we've read that many bytes. */
224 socklen_t rcvbuf_len
;
227 rcvbuf_len
= sizeof rcvbuf
;
228 if (getsockopt(fd
, SOL_SOCKET
, SO_RCVBUF
, &rcvbuf
, &rcvbuf_len
) < 0) {
229 static struct vlog_rate_limit rl
= VLOG_RATE_LIMIT_INIT(5, 10);
230 VLOG_ERR_RL(&rl
, "getsockopt(SO_RCVBUF) failed: %s", strerror(errno
));
234 /* In Linux, specifying MSG_TRUNC in the flags argument causes the
235 * datagram length to be returned, even if that is longer than the
236 * buffer provided. Thus, we can use a 1-byte buffer to discard the
237 * incoming datagram and still be able to account how many bytes were
238 * removed from the receive buffer.
240 * On other Unix-like OSes, MSG_TRUNC has no effect in the flags
242 char buffer
[LINUX
? 1 : 2048];
243 ssize_t n_bytes
= recv(fd
, buffer
, sizeof buffer
,
244 MSG_TRUNC
| MSG_DONTWAIT
);
245 if (n_bytes
<= 0 || n_bytes
>= rcvbuf
) {
253 /* Reads and discards up to 'n' datagrams from 'fd', stopping as soon as no
254 * more data can be immediately read. ('fd' should therefore be in
255 * non-blocking mode.)*/
257 drain_fd(int fd
, size_t n_packets
)
259 for (; n_packets
> 0; n_packets
--) {
260 /* 'buffer' only needs to be 1 byte long in most circumstances. This
261 * size is defensive against the possibility that we someday want to
262 * use a Linux tap device without TUN_NO_PI, in which case a buffer
263 * smaller than sizeof(struct tun_pi) will give EINVAL on read. */
265 if (read(fd
, buffer
, sizeof buffer
) <= 0) {
271 /* Stores in '*un' a sockaddr_un that refers to file 'name'. Stores in
272 * '*un_len' the size of the sockaddr_un. */
274 make_sockaddr_un__(const char *name
, struct sockaddr_un
*un
, socklen_t
*un_len
)
276 un
->sun_family
= AF_UNIX
;
277 ovs_strzcpy(un
->sun_path
, name
, sizeof un
->sun_path
);
278 *un_len
= (offsetof(struct sockaddr_un
, sun_path
)
279 + strlen (un
->sun_path
) + 1);
282 /* Stores in '*un' a sockaddr_un that refers to file 'name'. Stores in
283 * '*un_len' the size of the sockaddr_un.
285 * Returns 0 on success, otherwise a positive errno value. On success,
286 * '*dirfdp' is either -1 or a nonnegative file descriptor that the caller
287 * should close after using '*un' to bind or connect. On failure, '*dirfdp' is
290 make_sockaddr_un(const char *name
, struct sockaddr_un
*un
, socklen_t
*un_len
,
293 enum { MAX_UN_LEN
= sizeof un
->sun_path
- 1 };
296 if (strlen(name
) > MAX_UN_LEN
) {
297 static struct vlog_rate_limit rl
= VLOG_RATE_LIMIT_INIT(1, 1);
300 /* 'name' is too long to fit in a sockaddr_un, but we have a
301 * workaround for that on Linux: shorten it by opening a file
302 * descriptor for the directory part of the name and indirecting
303 * through /proc/self/fd/<dirfd>/<basename>. */
308 dir
= dir_name(name
);
309 base
= base_name(name
);
311 dirfd
= open(dir
, O_DIRECTORY
| O_RDONLY
);
318 short_name
= xasprintf("/proc/self/fd/%d/%s", dirfd
, base
);
322 if (strlen(short_name
) <= MAX_UN_LEN
) {
323 make_sockaddr_un__(short_name
, un
, un_len
);
331 VLOG_WARN_RL(&rl
, "Unix socket name %s is longer than maximum "
332 "%d bytes (even shortened)", name
, MAX_UN_LEN
);
334 /* 'name' is too long and we have no workaround. */
335 VLOG_WARN_RL(&rl
, "Unix socket name %s is longer than maximum "
336 "%d bytes", name
, MAX_UN_LEN
);
341 make_sockaddr_un__(name
, un
, un_len
);
346 /* Binds Unix domain socket 'fd' to a file with permissions 0700. */
348 bind_unix_socket(int fd
, struct sockaddr
*sun
, socklen_t sun_len
)
350 /* According to _Unix Network Programming_, umask should affect bind(). */
351 mode_t old_umask
= umask(0077);
352 int error
= bind(fd
, sun
, sun_len
) ? errno
: 0;
357 /* Creates a Unix domain socket in the given 'style' (either SOCK_DGRAM or
358 * SOCK_STREAM) that is bound to '*bind_path' (if 'bind_path' is non-null) and
359 * connected to '*connect_path' (if 'connect_path' is non-null). If 'nonblock'
360 * is true, the socket is made non-blocking. If 'passcred' is true, the socket
361 * is configured to receive SCM_CREDENTIALS control messages.
363 * Returns the socket's fd if successful, otherwise a negative errno value. */
365 make_unix_socket(int style
, bool nonblock
, bool passcred OVS_UNUSED
,
366 const char *bind_path
, const char *connect_path
)
371 fd
= socket(PF_UNIX
, style
, 0);
376 /* Set nonblocking mode right away, if we want it. This prevents blocking
377 * in connect(), if connect_path != NULL. (In turn, that's a corner case:
378 * it will only happen if style is SOCK_STREAM or SOCK_SEQPACKET, and only
379 * if a backlog of un-accepted connections has built up in the kernel.) */
381 int flags
= fcntl(fd
, F_GETFL
, 0);
386 if (fcntl(fd
, F_SETFL
, flags
| O_NONBLOCK
) == -1) {
393 struct sockaddr_un un
;
397 if (unlink(bind_path
) && errno
!= ENOENT
) {
398 VLOG_WARN("unlinking \"%s\": %s\n", bind_path
, strerror(errno
));
400 fatal_signal_add_file_to_unlink(bind_path
);
402 error
= make_sockaddr_un(bind_path
, &un
, &un_len
, &dirfd
);
404 error
= bind_unix_socket(fd
, (struct sockaddr
*) &un
, un_len
);
415 struct sockaddr_un un
;
419 error
= make_sockaddr_un(connect_path
, &un
, &un_len
, &dirfd
);
421 && connect(fd
, (struct sockaddr
*) &un
, un_len
)
422 && errno
!= EINPROGRESS
) {
433 #ifdef SCM_CREDENTIALS
436 if (setsockopt(fd
, SOL_SOCKET
, SO_PASSCRED
, &enable
, sizeof(enable
))) {
446 if (error
== EAGAIN
) {
450 fatal_signal_remove_file_to_unlink(bind_path
);
457 get_unix_name_len(socklen_t sun_len
)
459 return (sun_len
>= offsetof(struct sockaddr_un
, sun_path
)
460 ? sun_len
- offsetof(struct sockaddr_un
, sun_path
)
465 guess_netmask(ovs_be32 ip_
)
467 uint32_t ip
= ntohl(ip_
);
468 return ((ip
>> 31) == 0 ? htonl(0xff000000) /* Class A */
469 : (ip
>> 30) == 2 ? htonl(0xffff0000) /* Class B */
470 : (ip
>> 29) == 6 ? htonl(0xffffff00) /* Class C */
471 : htonl(0)); /* ??? */
474 /* Parses 'target', which should be a string in the format "<host>[:<port>]".
475 * <host> is required. If 'default_port' is nonzero then <port> is optional
476 * and defaults to 'default_port'.
478 * On success, returns true and stores the parsed remote address into '*sinp'.
479 * On failure, logs an error, stores zeros into '*sinp', and returns false. */
481 inet_parse_active(const char *target_
, uint16_t default_port
,
482 struct sockaddr_in
*sinp
)
484 char *target
= xstrdup(target_
);
485 char *save_ptr
= NULL
;
486 const char *host_name
;
487 const char *port_string
;
491 sinp
->sin_family
= AF_INET
;
492 sinp
->sin_port
= htons(default_port
);
495 host_name
= strtok_r(target
, ":", &save_ptr
);
496 port_string
= strtok_r(NULL
, ":", &save_ptr
);
498 VLOG_ERR("%s: bad peer name format", target_
);
502 /* Look up IP, port. */
503 if (lookup_ip(host_name
, &sinp
->sin_addr
)) {
506 if (port_string
&& atoi(port_string
)) {
507 sinp
->sin_port
= htons(atoi(port_string
));
508 } else if (!default_port
) {
509 VLOG_ERR("%s: port number must be specified", target_
);
517 memset(sinp
, 0, sizeof *sinp
);
523 /* Opens a non-blocking IPv4 socket of the specified 'style' and connects to
524 * 'target', which should be a string in the format "<host>[:<port>]". <host>
525 * is required. If 'default_port' is nonzero then <port> is optional and
526 * defaults to 'default_port'.
528 * 'style' should be SOCK_STREAM (for TCP) or SOCK_DGRAM (for UDP).
530 * On success, returns 0 (indicating connection complete) or EAGAIN (indicating
531 * connection in progress), in which case the new file descriptor is stored
532 * into '*fdp'. On failure, returns a positive errno value other than EAGAIN
533 * and stores -1 into '*fdp'.
535 * If 'sinp' is non-null, then on success the target address is stored into
538 inet_open_active(int style
, const char *target
, uint16_t default_port
,
539 struct sockaddr_in
*sinp
, int *fdp
)
541 struct sockaddr_in sin
;
546 if (!inet_parse_active(target
, default_port
, &sin
)) {
547 error
= EAFNOSUPPORT
;
551 /* Create non-blocking socket. */
552 fd
= socket(AF_INET
, style
, 0);
554 VLOG_ERR("%s: socket: %s", target
, strerror(errno
));
558 error
= set_nonblocking(fd
);
564 error
= connect(fd
, (struct sockaddr
*) &sin
, sizeof sin
) == 0 ? 0 : errno
;
565 if (error
== EINPROGRESS
) {
567 } else if (error
&& error
!= EAGAIN
) {
571 /* Success: error is 0 or EAGAIN. */
577 if (!error
|| error
== EAGAIN
) {
588 /* Parses 'target', which should be a string in the format "[<port>][:<ip>]":
590 * - If 'default_port' is -1, then <port> is required. Otherwise, if
591 * <port> is omitted, then 'default_port' is used instead.
593 * - If <port> (or 'default_port', if used) is 0, then no port is bound
594 * and the TCP/IP stack will select a port.
596 * - If <ip> is omitted then the IP address is wildcarded.
598 * If successful, stores the address into '*sinp' and returns true; otherwise
599 * zeros '*sinp' and returns false. */
601 inet_parse_passive(const char *target_
, uint16_t default_port
,
602 struct sockaddr_in
*sinp
)
604 char *target
= xstrdup(target_
);
605 char *string_ptr
= target
;
606 const char *host_name
;
607 const char *port_string
;
611 /* Address defaults. */
612 memset(sinp
, 0, sizeof *sinp
);
613 sinp
->sin_family
= AF_INET
;
614 sinp
->sin_addr
.s_addr
= htonl(INADDR_ANY
);
615 sinp
->sin_port
= htons(default_port
);
617 /* Parse optional port number. */
618 port_string
= strsep(&string_ptr
, ":");
619 if (port_string
&& str_to_int(port_string
, 10, &port
)) {
620 sinp
->sin_port
= htons(port
);
621 } else if (default_port
< 0) {
622 VLOG_ERR("%s: port number must be specified", target_
);
626 /* Parse optional bind IP. */
627 host_name
= strsep(&string_ptr
, ":");
628 if (host_name
&& host_name
[0] && lookup_ip(host_name
, &sinp
->sin_addr
)) {
636 memset(sinp
, 0, sizeof *sinp
);
643 /* Opens a non-blocking IPv4 socket of the specified 'style', binds to
644 * 'target', and listens for incoming connections. Parses 'target' in the same
645 * way was inet_parse_passive().
647 * 'style' should be SOCK_STREAM (for TCP) or SOCK_DGRAM (for UDP).
649 * For TCP, the socket will have SO_REUSEADDR turned on.
651 * On success, returns a non-negative file descriptor. On failure, returns a
652 * negative errno value.
654 * If 'sinp' is non-null, then on success the bound address is stored into
657 inet_open_passive(int style
, const char *target
, int default_port
,
658 struct sockaddr_in
*sinp
)
660 struct sockaddr_in sin
;
662 unsigned int yes
= 1;
664 if (!inet_parse_passive(target
, default_port
, &sin
)) {
668 /* Create non-blocking socket, set SO_REUSEADDR. */
669 fd
= socket(AF_INET
, style
, 0);
672 VLOG_ERR("%s: socket: %s", target
, strerror(error
));
675 error
= set_nonblocking(fd
);
679 if (style
== SOCK_STREAM
680 && setsockopt(fd
, SOL_SOCKET
, SO_REUSEADDR
, &yes
, sizeof yes
) < 0) {
682 VLOG_ERR("%s: setsockopt(SO_REUSEADDR): %s", target
, strerror(error
));
687 if (bind(fd
, (struct sockaddr
*) &sin
, sizeof sin
) < 0) {
689 VLOG_ERR("%s: bind: %s", target
, strerror(error
));
694 if (listen(fd
, 10) < 0) {
696 VLOG_ERR("%s: listen: %s", target
, strerror(error
));
701 socklen_t sin_len
= sizeof sin
;
702 if (getsockname(fd
, (struct sockaddr
*) &sin
, &sin_len
) < 0){
704 VLOG_ERR("%s: getsockname: %s", target
, strerror(error
));
707 if (sin
.sin_family
!= AF_INET
|| sin_len
!= sizeof sin
) {
708 VLOG_ERR("%s: getsockname: invalid socket name", target
);
721 /* Returns a readable and writable fd for /dev/null, if successful, otherwise
722 * a negative errno value. The caller must not close the returned fd (because
723 * the same fd will be handed out to subsequent callers). */
727 static int null_fd
= -1;
729 null_fd
= open("/dev/null", O_RDWR
);
732 VLOG_ERR("could not open /dev/null: %s", strerror(error
));
740 read_fully(int fd
, void *p_
, size_t size
, size_t *bytes_read
)
746 ssize_t retval
= read(fd
, p
, size
);
748 *bytes_read
+= retval
;
751 } else if (retval
== 0) {
753 } else if (errno
!= EINTR
) {
761 write_fully(int fd
, const void *p_
, size_t size
, size_t *bytes_written
)
763 const uint8_t *p
= p_
;
767 ssize_t retval
= write(fd
, p
, size
);
769 *bytes_written
+= retval
;
772 } else if (retval
== 0) {
773 VLOG_WARN("write returned 0");
775 } else if (errno
!= EINTR
) {
782 /* Given file name 'file_name', fsyncs the directory in which it is contained.
783 * Returns 0 if successful, otherwise a positive errno value. */
785 fsync_parent_dir(const char *file_name
)
791 dir
= dir_name(file_name
);
792 fd
= open(dir
, O_RDONLY
);
795 if (errno
== EINVAL
|| errno
== EROFS
) {
796 /* This directory does not support synchronization. Not
797 * really an error. */
800 VLOG_ERR("%s: fsync failed (%s)", dir
, strerror(error
));
806 VLOG_ERR("%s: open failed (%s)", dir
, strerror(error
));
813 /* Obtains the modification time of the file named 'file_name' to the greatest
814 * supported precision. If successful, stores the mtime in '*mtime' and
815 * returns 0. On error, returns a positive errno value and stores zeros in
818 get_mtime(const char *file_name
, struct timespec
*mtime
)
822 if (!stat(file_name
, &s
)) {
823 mtime
->tv_sec
= s
.st_mtime
;
825 #if HAVE_STRUCT_STAT_ST_MTIM_TV_NSEC
826 mtime
->tv_nsec
= s
.st_mtim
.tv_nsec
;
827 #elif HAVE_STRUCT_STAT_ST_MTIMENSEC
828 mtime
->tv_nsec
= s
.st_mtimensec
;
835 mtime
->tv_sec
= mtime
->tv_nsec
= 0;
844 VLOG_FATAL("failed to create pipe (%s)", strerror(errno
));
849 getsockopt_int(int fd
, int level
, int optname
, int *valuep
)
851 socklen_t len
= sizeof *valuep
;
853 return (getsockopt(fd
, level
, optname
, valuep
, &len
) ? errno
854 : len
== sizeof *valuep
? 0
859 describe_sockaddr(struct ds
*string
, int fd
,
860 int (*getaddr
)(int, struct sockaddr
*, socklen_t
*))
862 struct sockaddr_storage ss
;
863 socklen_t len
= sizeof ss
;
865 if (!getaddr(fd
, (struct sockaddr
*) &ss
, &len
)) {
866 if (ss
.ss_family
== AF_INET
) {
867 struct sockaddr_in sin
;
869 memcpy(&sin
, &ss
, sizeof sin
);
870 ds_put_format(string
, IP_FMT
":%"PRIu16
,
871 IP_ARGS(&sin
.sin_addr
.s_addr
), ntohs(sin
.sin_port
));
872 } else if (ss
.ss_family
== AF_UNIX
) {
873 struct sockaddr_un sun
;
877 memcpy(&sun
, &ss
, sizeof sun
);
878 maxlen
= len
- offsetof(struct sockaddr_un
, sun_path
);
879 null
= memchr(sun
.sun_path
, '\0', maxlen
);
880 ds_put_buffer(string
, sun
.sun_path
,
881 null
? null
- sun
.sun_path
: maxlen
);
884 else if (ss
.ss_family
== AF_NETLINK
) {
887 /* SO_PROTOCOL was introduced in 2.6.32. Support it regardless of the version
888 * of the Linux kernel headers in use at build time. */
890 #define SO_PROTOCOL 38
893 if (!getsockopt_int(fd
, SOL_SOCKET
, SO_PROTOCOL
, &protocol
)) {
896 ds_put_cstr(string
, "NETLINK_ROUTE");
899 case NETLINK_GENERIC
:
900 ds_put_cstr(string
, "NETLINK_GENERIC");
904 ds_put_format(string
, "AF_NETLINK family %d", protocol
);
908 ds_put_cstr(string
, "AF_NETLINK");
912 #if AF_PACKET && __linux__
913 else if (ss
.ss_family
== AF_PACKET
) {
914 struct sockaddr_ll sll
;
916 memcpy(&sll
, &ss
, sizeof sll
);
917 ds_put_cstr(string
, "AF_PACKET");
918 if (sll
.sll_ifindex
) {
921 if (if_indextoname(sll
.sll_ifindex
, name
)) {
922 ds_put_format(string
, "(%s)", name
);
924 ds_put_format(string
, "(ifindex=%d)", sll
.sll_ifindex
);
927 if (sll
.sll_protocol
) {
928 ds_put_format(string
, "(protocol=0x%"PRIu16
")",
929 ntohs(sll
.sll_protocol
));
933 else if (ss
.ss_family
== AF_UNSPEC
) {
934 ds_put_cstr(string
, "AF_UNSPEC");
936 ds_put_format(string
, "AF_%d", (int) ss
.ss_family
);
944 put_fd_filename(struct ds
*string
, int fd
)
950 linkname
= xasprintf("/proc/self/fd/%d", fd
);
951 n
= readlink(linkname
, buf
, sizeof buf
);
953 ds_put_char(string
, ' ');
954 ds_put_buffer(string
, buf
, n
);
955 if (n
> sizeof buf
) {
956 ds_put_cstr(string
, "...");
963 /* Returns a malloc()'d string describing 'fd', for use in logging. */
972 ds_put_format(&string
, "fstat failed (%s)", strerror(errno
));
973 } else if (S_ISSOCK(s
.st_mode
)) {
974 describe_sockaddr(&string
, fd
, getsockname
);
975 ds_put_cstr(&string
, "<->");
976 describe_sockaddr(&string
, fd
, getpeername
);
978 ds_put_cstr(&string
, (isatty(fd
) ? "tty"
979 : S_ISDIR(s
.st_mode
) ? "directory"
980 : S_ISCHR(s
.st_mode
) ? "character device"
981 : S_ISBLK(s
.st_mode
) ? "block device"
982 : S_ISREG(s
.st_mode
) ? "file"
983 : S_ISFIFO(s
.st_mode
) ? "FIFO"
984 : S_ISLNK(s
.st_mode
) ? "symbolic link"
987 put_fd_filename(&string
, fd
);
990 return ds_steal_cstr(&string
);