/openvswitch/lib/socket-util.c
C | 1395 lines | 1026 code | 161 blank | 208 comment | 228 complexity | 301dd0a4d2b7b47ca7e860691dbfd79b MD5 | raw file
Possible License(s): BSD-3-Clause, GPL-3.0, LGPL-3.0, Apache-2.0, LGPL-2.1, GPL-2.0, MIT
- /*
- * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at:
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- #include <config.h>
- #include "socket-util.h"
- #include <arpa/inet.h>
- #include <errno.h>
- #include <fcntl.h>
- #include <net/if.h>
- #include <netdb.h>
- #include <poll.h>
- #include <stddef.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <sys/ioctl.h>
- #include <sys/resource.h>
- #include <sys/socket.h>
- #include <sys/stat.h>
- #include <sys/uio.h>
- #include <sys/un.h>
- #include <unistd.h>
- #include "dynamic-string.h"
- #include "fatal-signal.h"
- #include "packets.h"
- #include "poll-loop.h"
- #include "util.h"
- #include "vlog.h"
- #if AF_PACKET && LINUX_DATAPATH
- #include <linux/if_packet.h>
- #endif
- #ifdef HAVE_NETLINK
- #include "netlink-protocol.h"
- #include "netlink-socket.h"
- #endif
- VLOG_DEFINE_THIS_MODULE(socket_util);
- /* #ifdefs make it a pain to maintain code: you have to try to build both ways.
- * Thus, this file compiles all of the code regardless of the target, by
- * writing "if (LINUX_DATAPATH)" instead of "#ifdef __linux__". */
- #ifndef LINUX_DATAPATH
- #define LINUX_DATAPATH 0
- #endif
- #ifndef O_DIRECTORY
- #define O_DIRECTORY 0
- #endif
- static int getsockopt_int(int fd, int level, int option, const char *optname,
- int *valuep);
- /* Sets 'fd' to non-blocking mode. Returns 0 if successful, otherwise a
- * positive errno value. */
- int
- set_nonblocking(int fd)
- {
- int flags = fcntl(fd, F_GETFL, 0);
- if (flags != -1) {
- if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) != -1) {
- return 0;
- } else {
- VLOG_ERR("fcntl(F_SETFL) failed: %s", ovs_strerror(errno));
- return errno;
- }
- } else {
- VLOG_ERR("fcntl(F_GETFL) failed: %s", ovs_strerror(errno));
- return errno;
- }
- }
- void
- xset_nonblocking(int fd)
- {
- if (set_nonblocking(fd)) {
- exit(EXIT_FAILURE);
- }
- }
- int
- set_dscp(int fd, uint8_t dscp)
- {
- int val;
- if (dscp > 63) {
- return EINVAL;
- }
- val = dscp << 2;
- if (setsockopt(fd, IPPROTO_IP, IP_TOS, &val, sizeof val)) {
- return errno;
- }
- return 0;
- }
- static bool
- rlim_is_finite(rlim_t limit)
- {
- if (limit == RLIM_INFINITY) {
- return false;
- }
- #ifdef RLIM_SAVED_CUR /* FreeBSD 8.0 lacks RLIM_SAVED_CUR. */
- if (limit == RLIM_SAVED_CUR) {
- return false;
- }
- #endif
- #ifdef RLIM_SAVED_MAX /* FreeBSD 8.0 lacks RLIM_SAVED_MAX. */
- if (limit == RLIM_SAVED_MAX) {
- return false;
- }
- #endif
- return true;
- }
- /* Returns the maximum valid FD value, plus 1. */
- int
- get_max_fds(void)
- {
- static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
- static int max_fds;
- if (ovsthread_once_start(&once)) {
- struct rlimit r;
- if (!getrlimit(RLIMIT_NOFILE, &r) && rlim_is_finite(r.rlim_cur)) {
- max_fds = r.rlim_cur;
- } else {
- VLOG_WARN("failed to obtain fd limit, defaulting to 1024");
- max_fds = 1024;
- }
- ovsthread_once_done(&once);
- }
- return max_fds;
- }
- /* Translates 'host_name', which must be a string representation of an IP
- * address, into a numeric IP address in '*addr'. Returns 0 if successful,
- * otherwise a positive errno value. */
- int
- lookup_ip(const char *host_name, struct in_addr *addr)
- {
- if (!inet_aton(host_name, addr)) {
- static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
- VLOG_ERR_RL(&rl, "\"%s\" is not a valid IP address", host_name);
- return ENOENT;
- }
- return 0;
- }
- /* Translates 'host_name', which must be a string representation of an IPv6
- * address, into a numeric IPv6 address in '*addr'. Returns 0 if successful,
- * otherwise a positive errno value. */
- int
- lookup_ipv6(const char *host_name, struct in6_addr *addr)
- {
- if (inet_pton(AF_INET6, host_name, addr) != 1) {
- static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
- VLOG_ERR_RL(&rl, "\"%s\" is not a valid IPv6 address", host_name);
- return ENOENT;
- }
- return 0;
- }
- /* Translates 'host_name', which must be a host name or a string representation
- * of an IP address, into a numeric IP address in '*addr'. Returns 0 if
- * successful, otherwise a positive errno value.
- *
- * Most Open vSwitch code should not use this because it causes deadlocks:
- * getaddrinfo() sends out a DNS request but that starts a new flow for which
- * OVS must set up a flow, but it can't because it's waiting for a DNS reply.
- * The synchronous lookup also delays other activity. (Of course we can solve
- * this but it doesn't seem worthwhile quite yet.) */
- int
- lookup_hostname(const char *host_name, struct in_addr *addr)
- {
- struct addrinfo *result;
- struct addrinfo hints;
- if (inet_aton(host_name, addr)) {
- return 0;
- }
- memset(&hints, 0, sizeof hints);
- hints.ai_family = AF_INET;
- switch (getaddrinfo(host_name, NULL, &hints, &result)) {
- case 0:
- *addr = ALIGNED_CAST(struct sockaddr_in *,
- result->ai_addr)->sin_addr;
- freeaddrinfo(result);
- return 0;
- #ifdef EAI_ADDRFAMILY
- case EAI_ADDRFAMILY:
- #endif
- case EAI_NONAME:
- case EAI_SERVICE:
- return ENOENT;
- case EAI_AGAIN:
- return EAGAIN;
- case EAI_BADFLAGS:
- case EAI_FAMILY:
- case EAI_SOCKTYPE:
- return EINVAL;
- case EAI_FAIL:
- return EIO;
- case EAI_MEMORY:
- return ENOMEM;
- #ifdef EAI_NODATA
- case EAI_NODATA:
- return ENXIO;
- #endif
- case EAI_SYSTEM:
- return errno;
- default:
- return EPROTO;
- }
- }
- int
- check_connection_completion(int fd)
- {
- static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 10);
- struct pollfd pfd;
- int retval;
- pfd.fd = fd;
- pfd.events = POLLOUT;
- do {
- retval = poll(&pfd, 1, 0);
- } while (retval < 0 && errno == EINTR);
- if (retval == 1) {
- if (pfd.revents & POLLERR) {
- ssize_t n = send(fd, "", 1, MSG_DONTWAIT);
- if (n < 0) {
- return errno;
- } else {
- VLOG_ERR_RL(&rl, "poll return POLLERR but send succeeded");
- return EPROTO;
- }
- }
- return 0;
- } else if (retval < 0) {
- VLOG_ERR_RL(&rl, "poll: %s", ovs_strerror(errno));
- return errno;
- } else {
- return EAGAIN;
- }
- }
- /* Drain all the data currently in the receive queue of a datagram socket (and
- * possibly additional data). There is no way to know how many packets are in
- * the receive queue, but we do know that the total number of bytes queued does
- * not exceed the receive buffer size, so we pull packets until none are left
- * or we've read that many bytes. */
- int
- drain_rcvbuf(int fd)
- {
- int rcvbuf;
- rcvbuf = get_socket_rcvbuf(fd);
- if (rcvbuf < 0) {
- return -rcvbuf;
- }
- while (rcvbuf > 0) {
- /* In Linux, specifying MSG_TRUNC in the flags argument causes the
- * datagram length to be returned, even if that is longer than the
- * buffer provided. Thus, we can use a 1-byte buffer to discard the
- * incoming datagram and still be able to account how many bytes were
- * removed from the receive buffer.
- *
- * On other Unix-like OSes, MSG_TRUNC has no effect in the flags
- * argument. */
- char buffer[LINUX_DATAPATH ? 1 : 2048];
- ssize_t n_bytes = recv(fd, buffer, sizeof buffer,
- MSG_TRUNC | MSG_DONTWAIT);
- if (n_bytes <= 0 || n_bytes >= rcvbuf) {
- break;
- }
- rcvbuf -= n_bytes;
- }
- return 0;
- }
- /* Returns the size of socket 'sock''s receive buffer (SO_RCVBUF), or a
- * negative errno value if an error occurs. */
- int
- get_socket_rcvbuf(int sock)
- {
- int rcvbuf;
- int error;
- error = getsockopt_int(sock, SOL_SOCKET, SO_RCVBUF, "SO_RCVBUF", &rcvbuf);
- return error ? -error : rcvbuf;
- }
- /* Reads and discards up to 'n' datagrams from 'fd', stopping as soon as no
- * more data can be immediately read. ('fd' should therefore be in
- * non-blocking mode.)*/
- void
- drain_fd(int fd, size_t n_packets)
- {
- for (; n_packets > 0; n_packets--) {
- /* 'buffer' only needs to be 1 byte long in most circumstances. This
- * size is defensive against the possibility that we someday want to
- * use a Linux tap device without TUN_NO_PI, in which case a buffer
- * smaller than sizeof(struct tun_pi) will give EINVAL on read. */
- char buffer[128];
- if (read(fd, buffer, sizeof buffer) <= 0) {
- break;
- }
- }
- }
- /* Stores in '*un' a sockaddr_un that refers to file 'name'. Stores in
- * '*un_len' the size of the sockaddr_un. */
- static void
- make_sockaddr_un__(const char *name, struct sockaddr_un *un, socklen_t *un_len)
- {
- un->sun_family = AF_UNIX;
- ovs_strzcpy(un->sun_path, name, sizeof un->sun_path);
- *un_len = (offsetof(struct sockaddr_un, sun_path)
- + strlen (un->sun_path) + 1);
- }
- /* Stores in '*un' a sockaddr_un that refers to file 'name'. Stores in
- * '*un_len' the size of the sockaddr_un.
- *
- * Returns 0 on success, otherwise a positive errno value. On success,
- * '*dirfdp' is either -1 or a nonnegative file descriptor that the caller
- * should close after using '*un' to bind or connect. On failure, '*dirfdp' is
- * -1. */
- static int
- make_sockaddr_un(const char *name, struct sockaddr_un *un, socklen_t *un_len,
- int *dirfdp)
- {
- enum { MAX_UN_LEN = sizeof un->sun_path - 1 };
- *dirfdp = -1;
- if (strlen(name) > MAX_UN_LEN) {
- static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
- if (LINUX_DATAPATH) {
- /* 'name' is too long to fit in a sockaddr_un, but we have a
- * workaround for that on Linux: shorten it by opening a file
- * descriptor for the directory part of the name and indirecting
- * through /proc/self/fd/<dirfd>/<basename>. */
- char *dir, *base;
- char *short_name;
- int dirfd;
- dir = dir_name(name);
- base = base_name(name);
- dirfd = open(dir, O_DIRECTORY | O_RDONLY);
- if (dirfd < 0) {
- free(base);
- free(dir);
- return errno;
- }
- short_name = xasprintf("/proc/self/fd/%d/%s", dirfd, base);
- free(dir);
- free(base);
- if (strlen(short_name) <= MAX_UN_LEN) {
- make_sockaddr_un__(short_name, un, un_len);
- free(short_name);
- *dirfdp = dirfd;
- return 0;
- }
- free(short_name);
- close(dirfd);
- VLOG_WARN_RL(&rl, "Unix socket name %s is longer than maximum "
- "%d bytes (even shortened)", name, MAX_UN_LEN);
- } else {
- /* 'name' is too long and we have no workaround. */
- VLOG_WARN_RL(&rl, "Unix socket name %s is longer than maximum "
- "%d bytes", name, MAX_UN_LEN);
- }
- return ENAMETOOLONG;
- } else {
- make_sockaddr_un__(name, un, un_len);
- return 0;
- }
- }
- /* Binds Unix domain socket 'fd' to a file with permissions 0700. */
- static int
- bind_unix_socket(int fd, struct sockaddr *sun, socklen_t sun_len)
- {
- /* According to _Unix Network Programming_, umask should affect bind(). */
- mode_t old_umask = umask(0077);
- int error = bind(fd, sun, sun_len) ? errno : 0;
- umask(old_umask);
- return error;
- }
- /* Creates a Unix domain socket in the given 'style' (either SOCK_DGRAM or
- * SOCK_STREAM) that is bound to '*bind_path' (if 'bind_path' is non-null) and
- * connected to '*connect_path' (if 'connect_path' is non-null). If 'nonblock'
- * is true, the socket is made non-blocking.
- *
- * Returns the socket's fd if successful, otherwise a negative errno value. */
- int
- make_unix_socket(int style, bool nonblock,
- const char *bind_path, const char *connect_path)
- {
- int error;
- int fd;
- fd = socket(PF_UNIX, style, 0);
- if (fd < 0) {
- return -errno;
- }
- /* Set nonblocking mode right away, if we want it. This prevents blocking
- * in connect(), if connect_path != NULL. (In turn, that's a corner case:
- * it will only happen if style is SOCK_STREAM or SOCK_SEQPACKET, and only
- * if a backlog of un-accepted connections has built up in the kernel.) */
- if (nonblock) {
- error = set_nonblocking(fd);
- if (error) {
- goto error;
- }
- }
- if (bind_path) {
- struct sockaddr_un un;
- socklen_t un_len;
- int dirfd;
- if (unlink(bind_path) && errno != ENOENT) {
- VLOG_WARN("unlinking \"%s\": %s\n",
- bind_path, ovs_strerror(errno));
- }
- fatal_signal_add_file_to_unlink(bind_path);
- error = make_sockaddr_un(bind_path, &un, &un_len, &dirfd);
- if (!error) {
- error = bind_unix_socket(fd, (struct sockaddr *) &un, un_len);
- }
- if (dirfd >= 0) {
- close(dirfd);
- }
- if (error) {
- goto error;
- }
- }
- if (connect_path) {
- struct sockaddr_un un;
- socklen_t un_len;
- int dirfd;
- error = make_sockaddr_un(connect_path, &un, &un_len, &dirfd);
- if (!error
- && connect(fd, (struct sockaddr*) &un, un_len)
- && errno != EINPROGRESS) {
- error = errno;
- }
- if (dirfd >= 0) {
- close(dirfd);
- }
- if (error) {
- goto error;
- }
- }
- return fd;
- error:
- if (error == EAGAIN) {
- error = EPROTO;
- }
- if (bind_path) {
- fatal_signal_unlink_file_now(bind_path);
- }
- close(fd);
- return -error;
- }
- int
- get_unix_name_len(socklen_t sun_len)
- {
- return (sun_len >= offsetof(struct sockaddr_un, sun_path)
- ? sun_len - offsetof(struct sockaddr_un, sun_path)
- : 0);
- }
- ovs_be32
- guess_netmask(ovs_be32 ip_)
- {
- uint32_t ip = ntohl(ip_);
- return ((ip >> 31) == 0 ? htonl(0xff000000) /* Class A */
- : (ip >> 30) == 2 ? htonl(0xffff0000) /* Class B */
- : (ip >> 29) == 6 ? htonl(0xffffff00) /* Class C */
- : htonl(0)); /* ??? */
- }
- /* Parses 'target', which should be a string in the format "<host>[:<port>]".
- * <host> is required. If 'default_port' is nonzero then <port> is optional
- * and defaults to 'default_port'.
- *
- * On success, returns true and stores the parsed remote address into '*sinp'.
- * On failure, logs an error, stores zeros into '*sinp', and returns false. */
- bool
- inet_parse_active(const char *target_, uint16_t default_port,
- struct sockaddr_in *sinp)
- {
- char *target = xstrdup(target_);
- char *save_ptr = NULL;
- const char *host_name;
- const char *port_string;
- bool ok = false;
- /* Defaults. */
- sinp->sin_family = AF_INET;
- sinp->sin_port = htons(default_port);
- /* Tokenize. */
- host_name = strtok_r(target, ":", &save_ptr);
- port_string = strtok_r(NULL, ":", &save_ptr);
- if (!host_name) {
- VLOG_ERR("%s: bad peer name format", target_);
- goto exit;
- }
- /* Look up IP, port. */
- if (lookup_ip(host_name, &sinp->sin_addr)) {
- goto exit;
- }
- if (port_string && atoi(port_string)) {
- sinp->sin_port = htons(atoi(port_string));
- } else if (!default_port) {
- VLOG_ERR("%s: port number must be specified", target_);
- goto exit;
- }
- ok = true;
- exit:
- if (!ok) {
- memset(sinp, 0, sizeof *sinp);
- }
- free(target);
- return ok;
- }
- /* Opens a non-blocking IPv4 socket of the specified 'style' and connects to
- * 'target', which should be a string in the format "<host>[:<port>]". <host>
- * is required. If 'default_port' is nonzero then <port> is optional and
- * defaults to 'default_port'.
- *
- * 'style' should be SOCK_STREAM (for TCP) or SOCK_DGRAM (for UDP).
- *
- * On success, returns 0 (indicating connection complete) or EAGAIN (indicating
- * connection in progress), in which case the new file descriptor is stored
- * into '*fdp'. On failure, returns a positive errno value other than EAGAIN
- * and stores -1 into '*fdp'.
- *
- * If 'sinp' is non-null, then on success the target address is stored into
- * '*sinp'.
- *
- * 'dscp' becomes the DSCP bits in the IP headers for the new connection. It
- * should be in the range [0, 63] and will automatically be shifted to the
- * appropriately place in the IP tos field. */
- int
- inet_open_active(int style, const char *target, uint16_t default_port,
- struct sockaddr_in *sinp, int *fdp, uint8_t dscp)
- {
- struct sockaddr_in sin;
- int fd = -1;
- int error;
- /* Parse. */
- if (!inet_parse_active(target, default_port, &sin)) {
- error = EAFNOSUPPORT;
- goto exit;
- }
- /* Create non-blocking socket. */
- fd = socket(AF_INET, style, 0);
- if (fd < 0) {
- VLOG_ERR("%s: socket: %s", target, ovs_strerror(errno));
- error = errno;
- goto exit;
- }
- error = set_nonblocking(fd);
- if (error) {
- goto exit;
- }
- /* The dscp bits must be configured before connect() to ensure that the TOS
- * field is set during the connection establishment. If set after
- * connect(), the handshake SYN frames will be sent with a TOS of 0. */
- error = set_dscp(fd, dscp);
- if (error) {
- VLOG_ERR("%s: socket: %s", target, ovs_strerror(error));
- goto exit;
- }
- /* Connect. */
- error = connect(fd, (struct sockaddr *) &sin, sizeof sin) == 0 ? 0 : errno;
- if (error == EINPROGRESS) {
- error = EAGAIN;
- }
- exit:
- if (!error || error == EAGAIN) {
- if (sinp) {
- *sinp = sin;
- }
- } else if (fd >= 0) {
- close(fd);
- fd = -1;
- }
- *fdp = fd;
- return error;
- }
- /* Parses 'target', which should be a string in the format "[<port>][:<ip>]":
- *
- * - If 'default_port' is -1, then <port> is required. Otherwise, if
- * <port> is omitted, then 'default_port' is used instead.
- *
- * - If <port> (or 'default_port', if used) is 0, then no port is bound
- * and the TCP/IP stack will select a port.
- *
- * - If <ip> is omitted then the IP address is wildcarded.
- *
- * If successful, stores the address into '*sinp' and returns true; otherwise
- * zeros '*sinp' and returns false. */
- bool
- inet_parse_passive(const char *target_, int default_port,
- struct sockaddr_in *sinp)
- {
- char *target = xstrdup(target_);
- char *string_ptr = target;
- const char *host_name;
- const char *port_string;
- bool ok = false;
- int port;
- /* Address defaults. */
- memset(sinp, 0, sizeof *sinp);
- sinp->sin_family = AF_INET;
- sinp->sin_addr.s_addr = htonl(INADDR_ANY);
- sinp->sin_port = htons(default_port);
- /* Parse optional port number. */
- port_string = strsep(&string_ptr, ":");
- if (port_string && str_to_int(port_string, 10, &port)) {
- sinp->sin_port = htons(port);
- } else if (default_port < 0) {
- VLOG_ERR("%s: port number must be specified", target_);
- goto exit;
- }
- /* Parse optional bind IP. */
- host_name = strsep(&string_ptr, ":");
- if (host_name && host_name[0] && lookup_ip(host_name, &sinp->sin_addr)) {
- goto exit;
- }
- ok = true;
- exit:
- if (!ok) {
- memset(sinp, 0, sizeof *sinp);
- }
- free(target);
- return ok;
- }
- /* Opens a non-blocking IPv4 socket of the specified 'style', binds to
- * 'target', and listens for incoming connections. Parses 'target' in the same
- * way was inet_parse_passive().
- *
- * 'style' should be SOCK_STREAM (for TCP) or SOCK_DGRAM (for UDP).
- *
- * For TCP, the socket will have SO_REUSEADDR turned on.
- *
- * On success, returns a non-negative file descriptor. On failure, returns a
- * negative errno value.
- *
- * If 'sinp' is non-null, then on success the bound address is stored into
- * '*sinp'.
- *
- * 'dscp' becomes the DSCP bits in the IP headers for the new connection. It
- * should be in the range [0, 63] and will automatically be shifted to the
- * appropriately place in the IP tos field. */
- int
- inet_open_passive(int style, const char *target, int default_port,
- struct sockaddr_in *sinp, uint8_t dscp)
- {
- bool kernel_chooses_port;
- struct sockaddr_in sin;
- int fd = 0, error;
- unsigned int yes = 1;
- if (!inet_parse_passive(target, default_port, &sin)) {
- return -EAFNOSUPPORT;
- }
- /* Create non-blocking socket, set SO_REUSEADDR. */
- fd = socket(AF_INET, style, 0);
- if (fd < 0) {
- error = errno;
- VLOG_ERR("%s: socket: %s", target, ovs_strerror(error));
- return -error;
- }
- error = set_nonblocking(fd);
- if (error) {
- goto error;
- }
- if (style == SOCK_STREAM
- && setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof yes) < 0) {
- error = errno;
- VLOG_ERR("%s: setsockopt(SO_REUSEADDR): %s",
- target, ovs_strerror(error));
- goto error;
- }
- /* Bind. */
- if (bind(fd, (struct sockaddr *) &sin, sizeof sin) < 0) {
- error = errno;
- VLOG_ERR("%s: bind: %s", target, ovs_strerror(error));
- goto error;
- }
- /* The dscp bits must be configured before connect() to ensure that the TOS
- * field is set during the connection establishment. If set after
- * connect(), the handshake SYN frames will be sent with a TOS of 0. */
- error = set_dscp(fd, dscp);
- if (error) {
- VLOG_ERR("%s: socket: %s", target, ovs_strerror(error));
- goto error;
- }
- /* Listen. */
- if (style == SOCK_STREAM && listen(fd, 10) < 0) {
- error = errno;
- VLOG_ERR("%s: listen: %s", target, ovs_strerror(error));
- goto error;
- }
- kernel_chooses_port = sin.sin_port == htons(0);
- if (sinp || kernel_chooses_port) {
- socklen_t sin_len = sizeof sin;
- if (getsockname(fd, (struct sockaddr *) &sin, &sin_len) < 0) {
- error = errno;
- VLOG_ERR("%s: getsockname: %s", target, ovs_strerror(error));
- goto error;
- }
- if (sin.sin_family != AF_INET || sin_len != sizeof sin) {
- error = EAFNOSUPPORT;
- VLOG_ERR("%s: getsockname: invalid socket name", target);
- goto error;
- }
- if (sinp) {
- *sinp = sin;
- }
- if (kernel_chooses_port) {
- VLOG_INFO("%s: listening on port %"PRIu16,
- target, ntohs(sin.sin_port));
- }
- }
- return fd;
- error:
- close(fd);
- return -error;
- }
- /* Returns a readable and writable fd for /dev/null, if successful, otherwise
- * a negative errno value. The caller must not close the returned fd (because
- * the same fd will be handed out to subsequent callers). */
- int
- get_null_fd(void)
- {
- static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
- static int null_fd;
- if (ovsthread_once_start(&once)) {
- null_fd = open("/dev/null", O_RDWR);
- if (null_fd < 0) {
- int error = errno;
- VLOG_ERR("could not open /dev/null: %s", ovs_strerror(error));
- null_fd = -error;
- }
- ovsthread_once_done(&once);
- }
- return null_fd;
- }
- int
- read_fully(int fd, void *p_, size_t size, size_t *bytes_read)
- {
- uint8_t *p = p_;
- *bytes_read = 0;
- while (size > 0) {
- ssize_t retval = read(fd, p, size);
- if (retval > 0) {
- *bytes_read += retval;
- size -= retval;
- p += retval;
- } else if (retval == 0) {
- return EOF;
- } else if (errno != EINTR) {
- return errno;
- }
- }
- return 0;
- }
- int
- write_fully(int fd, const void *p_, size_t size, size_t *bytes_written)
- {
- const uint8_t *p = p_;
- *bytes_written = 0;
- while (size > 0) {
- ssize_t retval = write(fd, p, size);
- if (retval > 0) {
- *bytes_written += retval;
- size -= retval;
- p += retval;
- } else if (retval == 0) {
- VLOG_WARN("write returned 0");
- return EPROTO;
- } else if (errno != EINTR) {
- return errno;
- }
- }
- return 0;
- }
- /* Given file name 'file_name', fsyncs the directory in which it is contained.
- * Returns 0 if successful, otherwise a positive errno value. */
- int
- fsync_parent_dir(const char *file_name)
- {
- int error = 0;
- char *dir;
- int fd;
- dir = dir_name(file_name);
- fd = open(dir, O_RDONLY);
- if (fd >= 0) {
- if (fsync(fd)) {
- if (errno == EINVAL || errno == EROFS) {
- /* This directory does not support synchronization. Not
- * really an error. */
- } else {
- error = errno;
- VLOG_ERR("%s: fsync failed (%s)", dir, ovs_strerror(error));
- }
- }
- close(fd);
- } else {
- error = errno;
- VLOG_ERR("%s: open failed (%s)", dir, ovs_strerror(error));
- }
- free(dir);
- return error;
- }
- /* Obtains the modification time of the file named 'file_name' to the greatest
- * supported precision. If successful, stores the mtime in '*mtime' and
- * returns 0. On error, returns a positive errno value and stores zeros in
- * '*mtime'. */
- int
- get_mtime(const char *file_name, struct timespec *mtime)
- {
- struct stat s;
- if (!stat(file_name, &s)) {
- mtime->tv_sec = s.st_mtime;
- #if HAVE_STRUCT_STAT_ST_MTIM_TV_NSEC
- mtime->tv_nsec = s.st_mtim.tv_nsec;
- #elif HAVE_STRUCT_STAT_ST_MTIMENSEC
- mtime->tv_nsec = s.st_mtimensec;
- #else
- mtime->tv_nsec = 0;
- #endif
- return 0;
- } else {
- mtime->tv_sec = mtime->tv_nsec = 0;
- return errno;
- }
- }
- void
- xpipe(int fds[2])
- {
- if (pipe(fds)) {
- VLOG_FATAL("failed to create pipe (%s)", ovs_strerror(errno));
- }
- }
- void
- xpipe_nonblocking(int fds[2])
- {
- xpipe(fds);
- xset_nonblocking(fds[0]);
- xset_nonblocking(fds[1]);
- }
- void
- xsocketpair(int domain, int type, int protocol, int fds[2])
- {
- if (socketpair(domain, type, protocol, fds)) {
- VLOG_FATAL("failed to create socketpair (%s)", ovs_strerror(errno));
- }
- }
- static int
- getsockopt_int(int fd, int level, int option, const char *optname, int *valuep)
- {
- static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 10);
- socklen_t len;
- int value;
- int error;
- len = sizeof value;
- if (getsockopt(fd, level, option, &value, &len)) {
- error = errno;
- VLOG_ERR_RL(&rl, "getsockopt(%s): %s", optname, ovs_strerror(error));
- } else if (len != sizeof value) {
- error = EINVAL;
- VLOG_ERR_RL(&rl, "getsockopt(%s): value is %u bytes (expected %zu)",
- optname, (unsigned int) len, sizeof value);
- } else {
- error = 0;
- }
- *valuep = error ? 0 : value;
- return error;
- }
- static void
- describe_sockaddr(struct ds *string, int fd,
- int (*getaddr)(int, struct sockaddr *, socklen_t *))
- {
- struct sockaddr_storage ss;
- socklen_t len = sizeof ss;
- if (!getaddr(fd, (struct sockaddr *) &ss, &len)) {
- if (ss.ss_family == AF_INET) {
- struct sockaddr_in sin;
- memcpy(&sin, &ss, sizeof sin);
- ds_put_format(string, IP_FMT":%"PRIu16,
- IP_ARGS(sin.sin_addr.s_addr), ntohs(sin.sin_port));
- } else if (ss.ss_family == AF_UNIX) {
- struct sockaddr_un sun;
- const char *null;
- size_t maxlen;
- memcpy(&sun, &ss, sizeof sun);
- maxlen = len - offsetof(struct sockaddr_un, sun_path);
- null = memchr(sun.sun_path, '\0', maxlen);
- ds_put_buffer(string, sun.sun_path,
- null ? null - sun.sun_path : maxlen);
- }
- #ifdef HAVE_NETLINK
- else if (ss.ss_family == AF_NETLINK) {
- int protocol;
- /* SO_PROTOCOL was introduced in 2.6.32. Support it regardless of the version
- * of the Linux kernel headers in use at build time. */
- #ifndef SO_PROTOCOL
- #define SO_PROTOCOL 38
- #endif
- if (!getsockopt_int(fd, SOL_SOCKET, SO_PROTOCOL, "SO_PROTOCOL",
- &protocol)) {
- switch (protocol) {
- case NETLINK_ROUTE:
- ds_put_cstr(string, "NETLINK_ROUTE");
- break;
- case NETLINK_GENERIC:
- ds_put_cstr(string, "NETLINK_GENERIC");
- break;
- default:
- ds_put_format(string, "AF_NETLINK family %d", protocol);
- break;
- }
- } else {
- ds_put_cstr(string, "AF_NETLINK");
- }
- }
- #endif
- #if AF_PACKET && LINUX_DATAPATH
- else if (ss.ss_family == AF_PACKET) {
- struct sockaddr_ll sll;
- memcpy(&sll, &ss, sizeof sll);
- ds_put_cstr(string, "AF_PACKET");
- if (sll.sll_ifindex) {
- char name[IFNAMSIZ];
- if (if_indextoname(sll.sll_ifindex, name)) {
- ds_put_format(string, "(%s)", name);
- } else {
- ds_put_format(string, "(ifindex=%d)", sll.sll_ifindex);
- }
- }
- if (sll.sll_protocol) {
- ds_put_format(string, "(protocol=0x%"PRIu16")",
- ntohs(sll.sll_protocol));
- }
- }
- #endif
- else if (ss.ss_family == AF_UNSPEC) {
- ds_put_cstr(string, "AF_UNSPEC");
- } else {
- ds_put_format(string, "AF_%d", (int) ss.ss_family);
- }
- }
- }
- #ifdef LINUX_DATAPATH
- static void
- put_fd_filename(struct ds *string, int fd)
- {
- char buf[1024];
- char *linkname;
- int n;
- linkname = xasprintf("/proc/self/fd/%d", fd);
- n = readlink(linkname, buf, sizeof buf);
- if (n > 0) {
- ds_put_char(string, ' ');
- ds_put_buffer(string, buf, n);
- if (n > sizeof buf) {
- ds_put_cstr(string, "...");
- }
- }
- free(linkname);
- }
- #endif
- /* Returns a malloc()'d string describing 'fd', for use in logging. */
- char *
- describe_fd(int fd)
- {
- struct ds string;
- struct stat s;
- ds_init(&string);
- if (fstat(fd, &s)) {
- ds_put_format(&string, "fstat failed (%s)", ovs_strerror(errno));
- } else if (S_ISSOCK(s.st_mode)) {
- describe_sockaddr(&string, fd, getsockname);
- ds_put_cstr(&string, "<->");
- describe_sockaddr(&string, fd, getpeername);
- } else {
- ds_put_cstr(&string, (isatty(fd) ? "tty"
- : S_ISDIR(s.st_mode) ? "directory"
- : S_ISCHR(s.st_mode) ? "character device"
- : S_ISBLK(s.st_mode) ? "block device"
- : S_ISREG(s.st_mode) ? "file"
- : S_ISFIFO(s.st_mode) ? "FIFO"
- : S_ISLNK(s.st_mode) ? "symbolic link"
- : "unknown"));
- #ifdef LINUX_DATAPATH
- put_fd_filename(&string, fd);
- #endif
- }
- return ds_steal_cstr(&string);
- }
- /* Returns the total of the 'iov_len' members of the 'n_iovs' in 'iovs'.
- * The caller must ensure that the total does not exceed SIZE_MAX. */
- size_t
- iovec_len(const struct iovec iovs[], size_t n_iovs)
- {
- size_t len = 0;
- size_t i;
- for (i = 0; i < n_iovs; i++) {
- len += iovs[i].iov_len;
- }
- return len;
- }
- /* Returns true if all of the 'n_iovs' iovecs in 'iovs' have length zero. */
- bool
- iovec_is_empty(const struct iovec iovs[], size_t n_iovs)
- {
- size_t i;
- for (i = 0; i < n_iovs; i++) {
- if (iovs[i].iov_len) {
- return false;
- }
- }
- return true;
- }
- /* Sends the 'n_iovs' iovecs of data in 'iovs' and the 'n_fds' file descriptors
- * in 'fds' on Unix domain socket 'sock'. Returns the number of bytes
- * successfully sent or -1 if an error occurred. On error, sets errno
- * appropriately. */
- int
- send_iovec_and_fds(int sock,
- const struct iovec *iovs, size_t n_iovs,
- const int fds[], size_t n_fds)
- {
- ovs_assert(sock >= 0);
- if (n_fds > 0) {
- union {
- struct cmsghdr cm;
- char control[CMSG_SPACE(SOUTIL_MAX_FDS * sizeof *fds)];
- } cmsg;
- struct msghdr msg;
- ovs_assert(!iovec_is_empty(iovs, n_iovs));
- ovs_assert(n_fds <= SOUTIL_MAX_FDS);
- memset(&cmsg, 0, sizeof cmsg);
- cmsg.cm.cmsg_len = CMSG_LEN(n_fds * sizeof *fds);
- cmsg.cm.cmsg_level = SOL_SOCKET;
- cmsg.cm.cmsg_type = SCM_RIGHTS;
- memcpy(CMSG_DATA(&cmsg.cm), fds, n_fds * sizeof *fds);
- msg.msg_name = NULL;
- msg.msg_namelen = 0;
- msg.msg_iov = CONST_CAST(struct iovec *, iovs);
- msg.msg_iovlen = n_iovs;
- msg.msg_control = &cmsg.cm;
- msg.msg_controllen = CMSG_SPACE(n_fds * sizeof *fds);
- msg.msg_flags = 0;
- return sendmsg(sock, &msg, 0);
- } else {
- return writev(sock, iovs, n_iovs);
- }
- }
- /* Sends the 'n_iovs' iovecs of data in 'iovs' and the 'n_fds' file descriptors
- * in 'fds' on Unix domain socket 'sock'. If 'skip_bytes' is nonzero, then the
- * first 'skip_bytes' of data in the iovecs are not sent, and none of the file
- * descriptors are sent. The function continues to retry sending until an
- * error (other than EINTR) occurs or all the data and fds are sent.
- *
- * Returns 0 if all the data and fds were successfully sent, otherwise a
- * positive errno value. Regardless of success, stores the number of bytes
- * sent (always at least 'skip_bytes') in '*bytes_sent'. (If at least one byte
- * is sent, then all the fds have been sent.)
- *
- * 'skip_bytes' must be less than or equal to iovec_len(iovs, n_iovs). */
- int
- send_iovec_and_fds_fully(int sock,
- const struct iovec iovs[], size_t n_iovs,
- const int fds[], size_t n_fds,
- size_t skip_bytes, size_t *bytes_sent)
- {
- *bytes_sent = 0;
- while (n_iovs > 0) {
- int retval;
- if (skip_bytes) {
- retval = skip_bytes;
- skip_bytes = 0;
- } else if (!*bytes_sent) {
- retval = send_iovec_and_fds(sock, iovs, n_iovs, fds, n_fds);
- } else {
- retval = writev(sock, iovs, n_iovs);
- }
- if (retval > 0) {
- *bytes_sent += retval;
- while (retval > 0) {
- const uint8_t *base = iovs->iov_base;
- size_t len = iovs->iov_len;
- if (retval < len) {
- size_t sent;
- int error;
- error = write_fully(sock, base + retval, len - retval,
- &sent);
- *bytes_sent += sent;
- retval += sent;
- if (error) {
- return error;
- }
- }
- retval -= len;
- iovs++;
- n_iovs--;
- }
- } else if (retval == 0) {
- if (iovec_is_empty(iovs, n_iovs)) {
- break;
- }
- VLOG_WARN("send returned 0");
- return EPROTO;
- } else if (errno != EINTR) {
- return errno;
- }
- }
- return 0;
- }
- /* Sends the 'n_iovs' iovecs of data in 'iovs' and the 'n_fds' file descriptors
- * in 'fds' on Unix domain socket 'sock'. The function continues to retry
- * sending until an error (other than EAGAIN or EINTR) occurs or all the data
- * and fds are sent. Upon EAGAIN, the function blocks until the socket is
- * ready for more data.
- *
- * Returns 0 if all the data and fds were successfully sent, otherwise a
- * positive errno value. */
- int
- send_iovec_and_fds_fully_block(int sock,
- const struct iovec iovs[], size_t n_iovs,
- const int fds[], size_t n_fds)
- {
- size_t sent = 0;
- for (;;) {
- int error;
- error = send_iovec_and_fds_fully(sock, iovs, n_iovs,
- fds, n_fds, sent, &sent);
- if (error != EAGAIN) {
- return error;
- }
- poll_fd_wait(sock, POLLOUT);
- poll_block();
- }
- }
- /* Attempts to receive from Unix domain socket 'sock' up to 'size' bytes of
- * data into 'data' and up to SOUTIL_MAX_FDS file descriptors into 'fds'.
- *
- * - Upon success, returns the number of bytes of data copied into 'data'
- * and stores the number of received file descriptors into '*n_fdsp'.
- *
- * - On failure, returns a negative errno value and stores 0 in
- * '*n_fdsp'.
- *
- * - On EOF, returns 0 and stores 0 in '*n_fdsp'. */
- int
- recv_data_and_fds(int sock,
- void *data, size_t size,
- int fds[SOUTIL_MAX_FDS], size_t *n_fdsp)
- {
- union {
- struct cmsghdr cm;
- char control[CMSG_SPACE(SOUTIL_MAX_FDS * sizeof *fds)];
- } cmsg;
- struct msghdr msg;
- int retval;
- struct cmsghdr *p;
- size_t i;
- *n_fdsp = 0;
- do {
- struct iovec iov;
- iov.iov_base = data;
- iov.iov_len = size;
- msg.msg_name = NULL;
- msg.msg_namelen = 0;
- msg.msg_iov = &iov;
- msg.msg_iovlen = 1;
- msg.msg_control = &cmsg.cm;
- msg.msg_controllen = sizeof cmsg.control;
- msg.msg_flags = 0;
- retval = recvmsg(sock, &msg, 0);
- } while (retval < 0 && errno == EINTR);
- if (retval <= 0) {
- return retval < 0 ? -errno : 0;
- }
- for (p = CMSG_FIRSTHDR(&msg); p; p = CMSG_NXTHDR(&msg, p)) {
- if (p->cmsg_level != SOL_SOCKET || p->cmsg_type != SCM_RIGHTS) {
- VLOG_ERR("unexpected control message %d:%d",
- p->cmsg_level, p->cmsg_type);
- goto error;
- } else if (*n_fdsp) {
- VLOG_ERR("multiple SCM_RIGHTS received");
- goto error;
- } else {
- size_t n_fds = (p->cmsg_len - CMSG_LEN(0)) / sizeof *fds;
- const int *fds_data = ALIGNED_CAST(const int *, CMSG_DATA(p));
- ovs_assert(n_fds > 0);
- if (n_fds > SOUTIL_MAX_FDS) {
- VLOG_ERR("%zu fds received but only %d supported",
- n_fds, SOUTIL_MAX_FDS);
- for (i = 0; i < n_fds; i++) {
- close(fds_data[i]);
- }
- goto error;
- }
- *n_fdsp = n_fds;
- memcpy(fds, fds_data, n_fds * sizeof *fds);
- }
- }
- return retval;
- error:
- for (i = 0; i < *n_fdsp; i++) {
- close(fds[i]);
- }
- *n_fdsp = 0;
- return EPROTO;
- }
- /* Calls ioctl() on an AF_INET sock, passing the specified 'command' and
- * 'arg'. Returns 0 if successful, otherwise a positive errno value. */
- int
- af_inet_ioctl(unsigned long int command, const void *arg)
- {
- static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
- static int sock;
- if (ovsthread_once_start(&once)) {
- sock = socket(AF_INET, SOCK_DGRAM, 0);
- if (sock < 0) {
- sock = -errno;
- VLOG_ERR("failed to create inet socket: %s", ovs_strerror(errno));
- }
- ovsthread_once_done(&once);
- }
- return (sock < 0 ? -sock
- : ioctl(sock, command, arg) == -1 ? errno
- : 0);
- }
- int
- af_inet_ifreq_ioctl(const char *name, struct ifreq *ifr, unsigned long int cmd,
- const char *cmd_name)
- {
- int error;
- ovs_strzcpy(ifr->ifr_name, name, sizeof ifr->ifr_name);
- error = af_inet_ioctl(cmd, ifr);
- if (error) {
- static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20);
- VLOG_DBG_RL(&rl, "%s: ioctl(%s) failed: %s", name, cmd_name,
- ovs_strerror(error));
- }
- return error;
- }