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ovs/lib/socket-util.c
Ben Pfaff cb22974d77 Replace most uses of assert by ovs_assert. 
This is a straight search-and-replace, except that I also removed #include
<assert.h> from each file where there were no assert calls left.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>
2013-01-16 16:03:37 -08:00

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/*
* Copyright (c) 2008, 2009, 2010, 2011, 2012 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/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", strerror(errno));
return errno;
}
} else {
VLOG_ERR("fcntl(F_GETFL) failed: %s", 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 int max_fds = -1;
if (max_fds < 0) {
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;
}
}
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:
* gethostbyname() 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 hostent *h;
if (inet_aton(host_name, addr)) {
return 0;
}
h = gethostbyname(host_name);
if (h) {
*addr = *(struct in_addr *) h->h_addr;
return 0;
}
return (h_errno == HOST_NOT_FOUND ? ENOENT
: h_errno == TRY_AGAIN ? EAGAIN
: h_errno == NO_RECOVERY ? EIO
: h_errno == NO_ADDRESS ? ENXIO
: EINVAL);
}
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", 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) {
int flags = fcntl(fd, F_GETFL, 0);
if (flags == -1) {
error = errno;
goto error;
}
if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1) {
error = errno;
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, 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, 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, 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)
{
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, 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, strerror(error));
goto error;
}
/* Bind. */
if (bind(fd, (struct sockaddr *) &sin, sizeof sin) < 0) {
error = errno;
VLOG_ERR("%s: bind: %s", target, 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, strerror(error));
goto error;
}
/* Listen. */
if (style == SOCK_STREAM && listen(fd, 10) < 0) {
error = errno;
VLOG_ERR("%s: listen: %s", target, strerror(error));
goto error;
}
if (sinp) {
socklen_t sin_len = sizeof sin;
if (getsockname(fd, (struct sockaddr *) &sin, &sin_len) < 0){
error = errno;
VLOG_ERR("%s: getsockname: %s", target, 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;
}
*sinp = sin;
}
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 int null_fd = -1;
if (null_fd < 0) {
null_fd = open("/dev/null", O_RDWR);
if (null_fd < 0) {
int error = errno;
VLOG_ERR("could not open /dev/null: %s", strerror(error));
return -error;
}
}
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, strerror(error));
}
}
close(fd);
} else {
error = errno;
VLOG_ERR("%s: open failed (%s)", dir, 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)", 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)", 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, 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)", 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 = (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;
}
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