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ovs/lib/socket-util.c
Gurucharan Shetty fc48c3ba30 socket-util: Fix dscp error check for Windows. 
Signed-off-by: Gurucharan Shetty <gshetty@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
2014-03-18 10:45:35 -07:00

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/*
* Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014 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/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 "ovs-thread.h"
#include "packets.h"
#include "poll-loop.h"
#include "util.h"
#include "vlog.h"
#ifdef __linux__
#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)" instead of "#ifdef __linux__". */
#ifdef __linux__
#define LINUX 1
#else
#define LINUX 0
#endif
#ifndef O_DIRECTORY
#define O_DIRECTORY 0
#endif
/* Maximum length of the sun_path member in a struct sockaddr_un, excluding
* space for a null terminator. */
#define MAX_UN_LEN (sizeof(((struct sockaddr_un *) 0)->sun_path) - 1)
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)
{
#ifndef _WIN32
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;
}
#else
unsigned long arg = 1;
if (ioctlsocket(fd, FIONBIO, &arg)) {
int error = sock_errno();
VLOG_ERR("set_nonblocking failed: %s", sock_strerror(error));
return error;
}
return 0;
#endif
}
void
xset_nonblocking(int fd)
{
if (set_nonblocking(fd)) {
exit(EXIT_FAILURE);
}
}
int
set_dscp(int fd, uint8_t dscp)
{
int val;
bool success;
if (dscp > 63) {
return EINVAL;
}
/* Note: this function is used for both of IPv4 and IPv6 sockets */
success = false;
val = dscp << 2;
if (setsockopt(fd, IPPROTO_IP, IP_TOS, &val, sizeof val)) {
#ifndef _WIN32
if (sock_errno() != ENOPROTOOPT) {
#else
if (sock_errno() != WSAENOPROTOOPT) {
#endif
return sock_errno();
}
} else {
success = true;
}
if (setsockopt(fd, IPPROTO_IPV6, IPV6_TCLASS, &val, sizeof val)) {
#ifndef _WIN32
if (sock_errno() != ENOPROTOOPT) {
#else
if (sock_errno() != WSAENOPROTOOPT) {
#endif
return sock_errno();
}
} else {
success = true;
}
if (!success) {
return ENOPROTOOPT;
}
return 0;
}
/* 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_pton(AF_INET, 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_pton(AF_INET, 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;
#if defined (EAI_NODATA) && EAI_NODATA != EAI_NONAME
case EAI_NODATA:
return ENXIO;
#endif
#ifdef EAI_SYSTEM
case EAI_SYSTEM:
return sock_errno();
#endif
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;
#ifndef _WIN32
do {
retval = poll(&pfd, 1, 0);
} while (retval < 0 && errno == EINTR);
#else
retval = WSAPoll(&pfd, 1, 0);
#endif
if (retval == 1) {
if (pfd.revents & POLLERR) {
ssize_t n = send(fd, "", 1, 0);
if (n < 0) {
return sock_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", sock_strerror(sock_errno()));
return errno;
} else {
return EAGAIN;
}
}
#ifndef _WIN32
/* 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 ? 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;
}
#endif
/* 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;
}
}
}
#ifndef _WIN32
/* Attempts to shorten 'name' by opening a file descriptor for the directory
* part of the name and indirecting through /proc/self/fd/<dirfd>/<basename>.
* On systems with Linux-like /proc, this works as long as <basename> isn't too
* long.
*
* On success, returns 0 and stores the short name in 'short_name' and a
* directory file descriptor to eventually be closed in '*dirfpd'. */
static int
shorten_name_via_proc(const char *name, char short_name[MAX_UN_LEN + 1],
int *dirfdp)
{
char *dir, *base;
int dirfd;
int len;
if (LINUX) {
return ENAMETOOLONG;
}
dir = dir_name(name);
dirfd = open(dir, O_DIRECTORY | O_RDONLY);
if (dirfd < 0) {
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
int error = errno;
VLOG_WARN_RL(&rl, "%s: open failed (%s)", dir, ovs_strerror(error));
free(dir);
return error;
}
free(dir);
base = base_name(name);
len = snprintf(short_name, MAX_UN_LEN + 1,
"/proc/self/fd/%d/%s", dirfd, base);
free(base);
if (len >= 0 && len <= MAX_UN_LEN) {
*dirfdp = dirfd;
return 0;
} else {
close(dirfd);
return ENAMETOOLONG;
}
}
/* Attempts to shorten 'name' by creating a symlink for the directory part of
* the name and indirecting through <symlink>/<basename>. This works on
* systems that support symlinks, as long as <basename> isn't too long.
*
* On success, returns 0 and stores the short name in 'short_name' and the
* symbolic link to eventually delete in 'linkname'. */
static int
shorten_name_via_symlink(const char *name, char short_name[MAX_UN_LEN + 1],
char linkname[MAX_UN_LEN + 1])
{
char *abs, *dir, *base;
const char *tmpdir;
int error;
int i;
abs = abs_file_name(NULL, name);
dir = dir_name(abs);
base = base_name(abs);
free(abs);
tmpdir = getenv("TMPDIR");
if (tmpdir == NULL) {
tmpdir = "/tmp";
}
for (i = 0; i < 1000; i++) {
int len;
len = snprintf(linkname, MAX_UN_LEN + 1,
"%s/ovs-un-c-%"PRIu32, tmpdir, random_uint32());
error = (len < 0 || len > MAX_UN_LEN ? ENAMETOOLONG
: symlink(dir, linkname) ? errno
: 0);
if (error != EEXIST) {
break;
}
}
if (!error) {
int len;
fatal_signal_add_file_to_unlink(linkname);
len = snprintf(short_name, MAX_UN_LEN + 1, "%s/%s", linkname, base);
if (len < 0 || len > MAX_UN_LEN) {
fatal_signal_unlink_file_now(linkname);
error = ENAMETOOLONG;
}
}
if (error) {
linkname[0] = '\0';
}
free(dir);
free(base);
return error;
}
/* 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.
*
* Uses '*dirfdp' and 'linkname' to store references to data when the caller no
* longer needs to use 'un'. On success, freeing these references with
* free_sockaddr_un() is mandatory to avoid a leak; on failure, freeing them is
* unnecessary but harmless. */
static int
make_sockaddr_un(const char *name, struct sockaddr_un *un, socklen_t *un_len,
int *dirfdp, char linkname[MAX_UN_LEN + 1])
{
char short_name[MAX_UN_LEN + 1];
*dirfdp = -1;
linkname[0] = '\0';
if (strlen(name) > MAX_UN_LEN) {
/* 'name' is too long to fit in a sockaddr_un. Try a workaround. */
int error = shorten_name_via_proc(name, short_name, dirfdp);
if (error == ENAMETOOLONG) {
error = shorten_name_via_symlink(name, short_name, linkname);
}
if (error) {
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
VLOG_WARN_RL(&rl, "Unix socket name %s is longer than maximum "
"%"PRIuSIZE" bytes", name, MAX_UN_LEN);
return error;
}
name = short_name;
}
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);
return 0;
}
/* Clean up after make_sockaddr_un(). */
static void
free_sockaddr_un(int dirfd, const char *linkname)
{
if (dirfd >= 0) {
close(dirfd);
}
if (linkname[0]) {
fatal_signal_unlink_file_now(linkname);
}
}
/* 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) {
char linkname[MAX_UN_LEN + 1];
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, linkname);
if (!error) {
error = bind_unix_socket(fd, (struct sockaddr *) &un, un_len);
}
free_sockaddr_un(dirfd, linkname);
if (error) {
goto error;
}
}
if (connect_path) {
char linkname[MAX_UN_LEN + 1];
struct sockaddr_un un;
socklen_t un_len;
int dirfd;
error = make_sockaddr_un(connect_path, &un, &un_len, &dirfd, linkname);
if (!error
&& connect(fd, (struct sockaddr*) &un, un_len)
&& errno != EINPROGRESS) {
error = errno;
}
free_sockaddr_un(dirfd, linkname);
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);
}
#endif /* _WIN32 */
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)); /* ??? */
}
/* This is like strsep() except:
*
* - The separator string is ":".
*
* - Square brackets [] quote ":" separators and are removed from the
* tokens. */
static char *
parse_bracketed_token(char **pp)
{
char *p = *pp;
if (p == NULL) {
return NULL;
} else if (*p == '\0') {
*pp = NULL;
return p;
} else if (*p == '[') {
char *start = p + 1;
char *end = start + strcspn(start, "]");
*pp = (*end == '\0' ? NULL
: end[1] == ':' ? end + 2
: end + 1);
*end = '\0';
return start;
} else {
char *start = p;
char *end = start + strcspn(start, ":");
*pp = *end == '\0' ? NULL : end + 1;
*end = '\0';
return start;
}
}
static bool
parse_sockaddr_components(struct sockaddr_storage *ss,
const char *host_s,
const char *port_s, uint16_t default_port,
const char *s)
{
struct sockaddr_in *sin = ALIGNED_CAST(struct sockaddr_in *, ss);
int port;
if (port_s && port_s[0]) {
if (!str_to_int(port_s, 10, &port) || port < 0 || port > 65535) {
VLOG_ERR("%s: bad port number \"%s\"", s, port_s);
}
} else {
port = default_port;
}
memset(ss, 0, sizeof *ss);
if (strchr(host_s, ':')) {
struct sockaddr_in6 *sin6
= ALIGNED_CAST(struct sockaddr_in6 *, ss);
sin6->sin6_family = AF_INET6;
sin6->sin6_port = htons(port);
if (!inet_pton(AF_INET6, host_s, sin6->sin6_addr.s6_addr)) {
VLOG_ERR("%s: bad IPv6 address \"%s\"", s, host_s);
goto exit;
}
} else {
sin->sin_family = AF_INET;
sin->sin_port = htons(port);
if (!inet_pton(AF_INET, host_s, &sin->sin_addr.s_addr)) {
VLOG_ERR("%s: bad IPv4 address \"%s\"", s, host_s);
goto exit;
}
}
return true;
exit:
memset(ss, 0, sizeof *ss);
return false;
}
/* Parses 'target', which should be a string in the format "<host>[:<port>]".
* <host>, which is required, may be an IPv4 address or an IPv6 address
* enclosed in square brackets. 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 '*ss'.
* On failure, logs an error, stores zeros into '*ss', and returns false. */
bool
inet_parse_active(const char *target_, uint16_t default_port,
struct sockaddr_storage *ss)
{
char *target = xstrdup(target_);
const char *port;
const char *host;
char *p;
bool ok;
p = target;
host = parse_bracketed_token(&p);
port = parse_bracketed_token(&p);
if (!host) {
VLOG_ERR("%s: host must be specified", target_);
ok = false;
} else if (!port && !default_port) {
VLOG_ERR("%s: port must be specified", target_);
ok = false;
} else {
ok = parse_sockaddr_components(ss, host, port, default_port, target_);
}
if (!ok) {
memset(ss, 0, sizeof *ss);
}
free(target);
return ok;
}
/* Opens a non-blocking IPv4 or IPv6 socket of the specified 'style' and
* connects to 'target', which should be a string in the format
* "<host>[:<port>]". <host>, which is required, may be an IPv4 address or an
* IPv6 address enclosed in square brackets. 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 'ss' is non-null, then on success stores the target address into '*ss'.
*
* '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_storage *ssp, int *fdp, uint8_t dscp)
{
struct sockaddr_storage ss;
int fd = -1;
int error;
/* Parse. */
if (!inet_parse_active(target, default_port, &ss)) {
error = EAFNOSUPPORT;
goto exit;
}
/* Create non-blocking socket. */
fd = socket(ss.ss_family, style, 0);
if (fd < 0) {
error = sock_errno();
VLOG_ERR("%s: socket: %s", target, sock_strerror(error));
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: set_dscp: %s", target, sock_strerror(error));
goto exit;
}
/* Connect. */
error = connect(fd, (struct sockaddr *) &ss, ss_length(&ss)) == 0
? 0
: sock_errno();
if (error == EINPROGRESS
#ifdef _WIN32
|| error == WSAEALREADY || error == WSAEWOULDBLOCK
#endif
) {
error = EAGAIN;
}
exit:
if (error && error != EAGAIN) {
if (ssp) {
memset(ssp, 0, sizeof *ssp);
}
if (fd >= 0) {
closesocket(fd);
fd = -1;
}
} else {
if (ssp) {
*ssp = ss;
}
}
*fdp = fd;
return error;
}
/* Parses 'target', which should be a string in the format "[<port>][:<host>]":
*
* - 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.
*
* - <host> is optional. If supplied, it may be an IPv4 address or an
* IPv6 address enclosed in square brackets. If omitted, the IP address
* is wildcarded.
*
* If successful, stores the address into '*ss' and returns true; otherwise
* zeros '*ss' and returns false. */
bool
inet_parse_passive(const char *target_, int default_port,
struct sockaddr_storage *ss)
{
char *target = xstrdup(target_);
const char *port;
const char *host;
char *p;
bool ok;
p = target;
port = parse_bracketed_token(&p);
host = parse_bracketed_token(&p);
if (!port && default_port < 0) {
VLOG_ERR("%s: port must be specified", target_);
ok = false;
} else {
ok = parse_sockaddr_components(ss, host ? host : "0.0.0.0",
port, default_port, target_);
}
if (!ok) {
memset(ss, 0, sizeof *ss);
}
free(target);
return ok;
}
/* Opens a non-blocking IPv4 or IPv6 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 'ss' is non-null, then on success stores the bound address into '*ss'.
*
* '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_storage *ssp, uint8_t dscp)
{
bool kernel_chooses_port;
struct sockaddr_storage ss;
int fd = 0, error;
unsigned int yes = 1;
if (!inet_parse_passive(target, default_port, &ss)) {
return -EAFNOSUPPORT;
}
kernel_chooses_port = ss_get_port(&ss) == 0;
/* Create non-blocking socket, set SO_REUSEADDR. */
fd = socket(ss.ss_family, style, 0);
if (fd < 0) {
error = sock_errno();
VLOG_ERR("%s: socket: %s", target, sock_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 = sock_errno();
VLOG_ERR("%s: setsockopt(SO_REUSEADDR): %s",
target, sock_strerror(error));
goto error;
}
/* Bind. */
if (bind(fd, (struct sockaddr *) &ss, ss_length(&ss)) < 0) {
error = sock_errno();
VLOG_ERR("%s: bind: %s", target, sock_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: set_dscp: %s", target, sock_strerror(error));
goto error;
}
/* Listen. */
if (style == SOCK_STREAM && listen(fd, 10) < 0) {
error = sock_errno();
VLOG_ERR("%s: listen: %s", target, sock_strerror(error));
goto error;
}
if (ssp || kernel_chooses_port) {
socklen_t ss_len = sizeof ss;
if (getsockname(fd, (struct sockaddr *) &ss, &ss_len) < 0) {
error = sock_errno();
VLOG_ERR("%s: getsockname: %s", target, sock_strerror(error));
goto error;
}
if (kernel_chooses_port) {
VLOG_INFO("%s: listening on port %"PRIu16,
target, ss_get_port(&ss));
}
if (ssp) {
*ssp = ss;
}
}
return fd;
error:
if (ssp) {
memset(ssp, 0, sizeof *ssp);
}
closesocket(fd);
return -error;
}
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;
#ifndef _WIN32
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);
#endif
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;
}
}
#ifndef _WIN32
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]);
}
#endif
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 = sock_errno();
VLOG_ERR_RL(&rl, "getsockopt(%s): %s", optname, sock_strerror(error));
} else if (len != sizeof value) {
error = EINVAL;
VLOG_ERR_RL(&rl, "getsockopt(%s): value is %u bytes (expected %"PRIuSIZE")",
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 || ss.ss_family == AF_INET6) {
char addrbuf[SS_NTOP_BUFSIZE];
ds_put_format(string, "%s:%"PRIu16,
ss_format_address(&ss, addrbuf, sizeof addrbuf),
ss_get_port(&ss));
#ifndef _WIN32
} 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);
#endif
}
#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 __linux__
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__
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);
#ifndef _WIN32
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__
put_fd_filename(&string, fd);
#endif
}
#else
ds_put_format(&string,"file descriptor");
#endif /* _WIN32 */
return ds_steal_cstr(&string);
}
#ifndef _WIN32
/* 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) {
int error = sock_errno();
VLOG_ERR("failed to create inet socket: %s", sock_strerror(error));
sock = -error;
}
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;
}
#endif
/* sockaddr_storage helpers. */
/* Returns the IPv4 or IPv6 port in 'ss'. */
uint16_t
ss_get_port(const struct sockaddr_storage *ss)
{
if (ss->ss_family == AF_INET) {
const struct sockaddr_in *sin
= ALIGNED_CAST(const struct sockaddr_in *, ss);
return ntohs(sin->sin_port);
} else if (ss->ss_family == AF_INET6) {
const struct sockaddr_in6 *sin6
= ALIGNED_CAST(const struct sockaddr_in6 *, ss);
return ntohs(sin6->sin6_port);
} else {
OVS_NOT_REACHED();
}
}
/* Formats the IPv4 or IPv6 address in 'ss' into the 'bufsize' bytes in 'buf'.
* If 'ss' is an IPv6 address, puts square brackets around the address.
* 'bufsize' should be at least SS_NTOP_BUFSIZE.
*
* Returns 'buf'. */
char *
ss_format_address(const struct sockaddr_storage *ss,
char *buf, size_t bufsize)
{
ovs_assert(bufsize >= SS_NTOP_BUFSIZE);
if (ss->ss_family == AF_INET) {
const struct sockaddr_in *sin
= ALIGNED_CAST(const struct sockaddr_in *, ss);
snprintf(buf, bufsize, IP_FMT, IP_ARGS(sin->sin_addr.s_addr));
} else if (ss->ss_family == AF_INET6) {
const struct sockaddr_in6 *sin6
= ALIGNED_CAST(const struct sockaddr_in6 *, ss);
buf[0] = '[';
inet_ntop(AF_INET6, sin6->sin6_addr.s6_addr, buf + 1, bufsize - 1);
strcpy(strchr(buf, '\0'), "]");
} else {
OVS_NOT_REACHED();
}
return buf;
}
size_t
ss_length(const struct sockaddr_storage *ss)
{
switch (ss->ss_family) {
case AF_INET:
return sizeof(struct sockaddr_in);
case AF_INET6:
return sizeof(struct sockaddr_in6);
default:
OVS_NOT_REACHED();
}
}
/* For Windows socket calls, 'errno' is not set. One has to call
* WSAGetLastError() to get the error number and then pass it to
* this function to get the correct error string.
*
* ovs_strerror() calls strerror_r() and would not get the correct error
* string for Windows sockets, but is good for POSIX. */
const char *
sock_strerror(int error)
{
#ifdef _WIN32
return ovs_format_message(error);
#else
return ovs_strerror(error);
#endif
}
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