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/*
* Utility functions for network connections.
*
* This is a collection of utility functions for network connections and
* socket creation, encapsulating some of the complexities of IPv4 and IPv6
* support and abstracting operations common to most network code.
*
* All of the portability difficulties with supporting IPv4 and IPv6 should be
* encapsulated in the combination of this code and replacement
* implementations for functions that aren't found on some pre-IPv6 systems.
* No other part of the source tree should have to care about IPv4 vs. IPv6.
*
* In this file, casts through void * or const void * of struct sockaddr *
* parameters are to silence gcc warnings with -Wcast-align. The specific
* address types often require stronger alignment than a struct sockaddr, and
* were originally allocated with that alignment. GCC doesn't have a good way
* of knowing that this code is correct.
*
* The canonical version of this file is maintained in the rra-c-util package,
* which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>.
*
* Written by Russ Allbery <eagle@eyrie.org>
* Copyright 2014 Russ Allbery <eagle@eyrie.org>
* Copyright 2009, 2011, 2012, 2013, 2014
* The Board of Trustees of the Leland Stanford Junior University
* Copyright (c) 2004, 2005, 2006, 2007, 2008
* by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 1991, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
* 2002, 2003 by The Internet Software Consortium and Rich Salz
*
* This code is derived from software contributed to the Internet Software
* Consortium by Rich Salz.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
#include <config.h>
#include <portable/system.h>
#include <portable/socket.h>
#include <errno.h>
#ifdef HAVE_SYS_SELECT_H
# include <sys/select.h>
#endif
#ifdef HAVE_SYS_TIME_H
# include <sys/time.h>
#endif
#include <time.h>
#include <util/fdflag.h>
#include <util/macros.h>
#include <util/messages.h>
#include <util/network.h>
#include <util/xmalloc.h>
#include <util/xwrite.h>
/* Macros to set the len attribute of sockaddrs. */
#if HAVE_STRUCT_SOCKADDR_SA_LEN
# define sin_set_length(s) ((s)->sin_len = sizeof(struct sockaddr_in))
# define sin6_set_length(s) ((s)->sin6_len = sizeof(struct sockaddr_in6))
#else
# define sin_set_length(s) /* empty */
# define sin6_set_length(s) /* empty */
#endif
/* If SO_REUSEADDR isn't available, make calls to set_reuseaddr go away. */
#ifndef SO_REUSEADDR
# define network_set_reuseaddr(fd) /* empty */
#endif
/* If IPV6_V6ONLY isn't available, make calls to set_v6only go away. */
#ifndef IPV6_V6ONLY
# define network_set_v6only(fd) /* empty */
#endif
/* If IP_FREEBIND isn't available, make calls to set_freebind go away. */
#ifndef IP_FREEBIND
# define network_set_freebind(fd) /* empty */
#endif
/*
* Windows requires a different function when sending to sockets, but can't
* return short writes on blocking sockets.
*/
#ifdef _WIN32
# define socket_xwrite(fd, b, s) send((fd), (b), (s), 0)
#else
# define socket_xwrite(fd, b, s) xwrite((fd), (b), (s))
#endif
/*
* Set SO_REUSEADDR on a socket if possible (so that something new can listen
* on the same port immediately if the daemon dies unexpectedly).
*/
#ifdef SO_REUSEADDR
static void
network_set_reuseaddr(socket_type fd)
{
int flag = 1;
const void *flagaddr = &flag;
if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, flagaddr, sizeof(flag)) < 0)
syswarn("cannot mark bind address reusable");
}
#endif
/*
* Set IPV6_V6ONLY on a socket if possible, since the IPv6 behavior is more
* consistent and easier to understand.
*/
#ifdef IPV6_V6ONLY
static void UNUSED
network_set_v6only(socket_type fd)
{
int flag = 1;
if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &flag, sizeof(flag)) < 0)
syswarn("cannot set IPv6 socket to v6only");
}
#endif
/*
* Set IP_FREEBIND on a socket if possible, which allows binding servers to
* IPv6 addresses that may not have been set up yet.
*/
#ifdef IP_FREEBIND
static void UNUSED
network_set_freebind(socket_type fd)
{
int flag = 1;
if (setsockopt(fd, IPPROTO_IP, IP_FREEBIND, &flag, sizeof(flag)) < 0)
syswarn("cannot set IPv6 socket to free binding");
}
#endif
/*
* Create an IPv4 socket and bind it, returning the resulting file descriptor
* (or INVALID_SOCKET on a failure).
*/
socket_type
network_bind_ipv4(int type, const char *address, unsigned short port)
{
socket_type fd;
struct sockaddr_in server;
struct in_addr addr;
/* Create the socket. */
fd = socket(PF_INET, type, IPPROTO_IP);
if (fd == INVALID_SOCKET) {
syswarn("cannot create IPv4 socket for %s, port %hu", address, port);
return INVALID_SOCKET;
}
network_set_reuseaddr(fd);
/* Accept "any" or "all" in the bind address to mean 0.0.0.0. */
if (!strcmp(address, "any") || !strcmp(address, "all"))
address = "0.0.0.0";
/* Flesh out the socket and do the bind. */
memset(&server, 0, sizeof(server));
server.sin_family = AF_INET;
server.sin_port = htons(port);
if (!inet_aton(address, &addr)) {
warn("invalid IPv4 address %s", address);
socket_set_errno_einval();
return INVALID_SOCKET;
}
server.sin_addr = addr;
sin_set_length(&server);
if (bind(fd, (struct sockaddr *) &server, sizeof(server)) < 0) {
syswarn("cannot bind socket for %s, port %hu", address, port);
socket_close(fd);
return INVALID_SOCKET;
}
return fd;
}
/*
* Create an IPv6 socket and bind it, returning the resulting file descriptor
* (or INVALID_SOCKET on a failure). This socket will be restricted to IPv6
* only if possible (as opposed to the standard behavior of binding IPv6
* sockets to both IPv6 and IPv4).
*
* Note that we don't warn (but still return failure) if the reason for the
* socket creation failure is that IPv6 isn't supported; this is to handle
* systems like many Linux hosts where IPv6 is available in userland but the
* kernel doesn't support it.
*/
#if HAVE_INET6
socket_type
network_bind_ipv6(int type, const char *address, unsigned short port)
{
socket_type fd;
struct sockaddr_in6 server;
struct in6_addr addr;
/* Create the socket. */
fd = socket(PF_INET6, type, IPPROTO_IP);
if (fd == INVALID_SOCKET) {
if (socket_errno != EAFNOSUPPORT && socket_errno != EPROTONOSUPPORT)
syswarn("cannot create IPv6 socket for %s, port %hu", address,
port);
return INVALID_SOCKET;
}
network_set_reuseaddr(fd);
/*
* Restrict the socket to IPv6 only if possible. The default behavior is
* to bind IPv6 sockets to both IPv6 and IPv4 for backward compatibility,
* but this causes various other problems (such as with reusing sockets
* and requiring handling of mapped addresses). Continue on if this
* fails, however.
*/
network_set_v6only(fd);
/* Accept "any" or "all" in the bind address to mean ::. */
if (!strcmp(address, "any") || !strcmp(address, "all"))
address = "::";
/*
* If the address is not ::, use IP_FREEBIND if it's available. This
* allows the network stack to bind to an address that isn't configured.
* We lose diagnosis of errors from specifying bind addresses that don't
* exist on the system, but we gain the ability to bind to IPv6 addresses
* that aren't yet configured. Since IPv6 address configuration can take
* unpredictable amounts of time during system setup, this is more robust.
*
* Ensure there is always a block here to avoid compiler warnings, since
* network_set_freebind() may expand into nothing.
*/
if (strcmp(address, "::") != 0) {
network_set_freebind(fd);
}
/* Flesh out the socket and do the bind. */
memset(&server, 0, sizeof(server));
server.sin6_family = AF_INET6;
server.sin6_port = htons(port);
if (inet_pton(AF_INET6, address, &addr) < 1) {
warn("invalid IPv6 address %s", address);
socket_set_errno_einval();
return INVALID_SOCKET;
}
server.sin6_addr = addr;
sin6_set_length(&server);
if (bind(fd, (struct sockaddr *) &server, sizeof(server)) < 0) {
syswarn("cannot bind socket for %s, port %hu", address, port);
socket_close(fd);
return INVALID_SOCKET;
}
return fd;
}
#else /* HAVE_INET6 */
socket_type
network_bind_ipv6(int type UNUSED, const char *address, unsigned short port)
{
warn("cannot bind %s, port %hu: IPv6 not supported", address, port);
socket_set_errno(EPROTONOSUPPORT);
return INVALID_SOCKET;
}
#endif /* HAVE_INET6 */
/*
* Create and bind sockets for every local address, as determined by
* getaddrinfo if IPv6 is available (otherwise, just use the IPv4 loopback
* address). Takes the socket type and port number, and then a pointer to an
* array of integers and a pointer to a count of them. Allocates a new array
* to hold the file descriptors and stores the count in the fourth argument.
*/
#if HAVE_INET6
bool
network_bind_all(int type, unsigned short port, socket_type **fds,
unsigned int *count)
{
struct addrinfo hints, *addrs, *addr;
unsigned int size;
int status;
socket_type fd;
char service[16], name[INET6_ADDRSTRLEN];
*count = 0;
/* Do the query to find all the available addresses. */
memset(&hints, 0, sizeof(hints));
hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG;
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = type;
status = snprintf(service, sizeof(service), "%hu", port);
if (status < 0 || (size_t) status > sizeof(service)) {
warn("cannot convert port %hu to string", port);
socket_set_errno_einval();
return false;
}
status = getaddrinfo(NULL, service, &hints, &addrs);
if (status < 0) {
warn("getaddrinfo for %s failed: %s", service, gai_strerror(status));
socket_set_errno_einval();
return false;
}
/*
* Now, try to bind each of them. Start the fds array at two entries,
* assuming an IPv6 and IPv4 socket, and grow it by two when necessary.
*/
size = 2;
*fds = xcalloc(size, sizeof(socket_type));
for (addr = addrs; addr != NULL; addr = addr->ai_next) {
network_sockaddr_sprint(name, sizeof(name), addr->ai_addr);
if (addr->ai_family == AF_INET)
fd = network_bind_ipv4(type, name, port);
else if (addr->ai_family == AF_INET6)
fd = network_bind_ipv6(type, name, port);
else
continue;
if (fd != INVALID_SOCKET) {
if (*count >= size) {
size += 2;
*fds = xreallocarray(*fds, size, sizeof(socket_type));
}
(*fds)[*count] = fd;
(*count)++;
}
}
freeaddrinfo(addrs);
return (*count > 0);
}
#else /* HAVE_INET6 */
bool
network_bind_all(int type, unsigned short port, socket_type **fds,
unsigned int *count)
{
socket_type fd;
fd = network_bind_ipv4(type, "0.0.0.0", port);
if (fd == INVALID_SOCKET) {
*fds = NULL;
*count = 0;
return false;
}
*fds = xmalloc(sizeof(socket_type));
*fds[0] = fd;
*count = 1;
return true;
}
#endif /* HAVE_INET6 */
/*
* Free the array of file descriptors allocated by network_bind_all. This is
* a simple wrapper around free, needed on platforms where libraries allocate
* memory from a different memory domain than programs (such as Windows).
*/
void
network_bind_all_free(socket_type *fds)
{
free(fds);
}
/*
* Given an array of file descriptors and the length of that array (the same
* data that's returned by network_bind_all), wait for an incoming connection
* on any of those sockets and return the file descriptor that selects ready
* for read.
*
* This is primarily intended for UDP services listening on multiple file
* descriptors, and also provides part of the code for network_accept_any.
* TCP services will probably want to use network_accept_any instead.
*
* Returns the new socket on success or INVALID_SOCKET on failure. Note that
* INVALID_SOCKET may be returned if the timeout is interrupted by a signal,
* which is not, precisely speaking, an error condition. In this case, errno
* will be set to EINTR.
*
* This is not intended to be a replacement for a full event loop, just some
* simple shared code for UDP services.
*/
socket_type
network_wait_any(socket_type fds[], unsigned int count)
{
fd_set readfds;
socket_type maxfd, fd;
unsigned int i;
int status;
FD_ZERO(&readfds);
maxfd = -1;
for (i = 0; i < count; i++) {
FD_SET(fds[i], &readfds);
if (fds[i] > maxfd)
maxfd = fds[i];
}
status = select(maxfd + 1, &readfds, NULL, NULL, NULL);
if (status < 0)
return INVALID_SOCKET;
fd = INVALID_SOCKET;
for (i = 0; i < count; i++)
if (FD_ISSET(fds[i], &readfds)) {
fd = fds[i];
break;
}
return fd;
}
/*
* Given an array of file descriptors and the length of that array (the same
* data that's returned by network_bind_all), wait for an incoming connection
* on any of those sockets, accept the connection with accept(), and return
* the new file descriptor.
*
* This is essentially a replacement for accept() with a single socket for
* daemons that are listening to multiple separate bound sockets, possibly
* because they need to listen to specific interfaces or possibly because
* they're listening for both IPv4 and IPv6 connections.
*
* Returns the new socket on success or INVALID_SOCKET on failure. On
* success, fills out the arguments with the address and address length of the
* accepted client. No error will be reported, so the caller should do that.
* Note that INVALID_SOCKET may be returned if the timeout is interrupted by a
* signal, which is not, precisely speaking, an error condition. In this
* case, errno will be set to EINTR.
*/
socket_type
network_accept_any(socket_type fds[], unsigned int count,
struct sockaddr *addr, socklen_t *addrlen)
{
socket_type fd;
fd = network_wait_any(fds, count);
if (fd == INVALID_SOCKET)
return INVALID_SOCKET;
else
return accept(fd, addr, addrlen);
}
/*
* Binds the given socket to an appropriate source address for its family
* using the provided source address. Returns true on success and false on
* failure.
*/
static bool
network_source(socket_type fd, int family, const char *source)
{
if (source == NULL)
return true;
if (strcmp(source, "all") == 0 || strcmp(source, "any") == 0)
return true;
if (family == AF_INET) {
struct sockaddr_in saddr;
memset(&saddr, 0, sizeof(saddr));
saddr.sin_family = AF_INET;
if (!inet_aton(source, &saddr.sin_addr)) {
socket_set_errno_einval();
return false;
}
return bind(fd, (struct sockaddr *) &saddr, sizeof(saddr)) == 0;
}
#ifdef HAVE_INET6
else if (family == AF_INET6) {
struct sockaddr_in6 saddr;
memset(&saddr, 0, sizeof(saddr));
saddr.sin6_family = AF_INET6;
if (inet_pton(AF_INET6, source, &saddr.sin6_addr) < 1) {
socket_set_errno_einval();
return false;
}
return bind(fd, (struct sockaddr *) &saddr, sizeof(saddr)) == 0;
}
#endif
else {
socket_set_errno(EAFNOSUPPORT);
return false;
}
}
/*
* Internal helper function that waits for a non-blocking connect to complete
* on a socket. Takes the file descriptor and the timeout. Returns 0 on a
* successful completion of the connect within the timeout and -1 on failure.
* On failure, sets the socket errno.
*/
static int
connect_wait(socket_type fd, time_t timeout)
{
int status, err;
socklen_t length;
struct timeval tv;
fd_set set;
/*
* Use select to poll the file descriptor. Loop if interrupted by a
* caught signal. This means we could wait for longer than the timeout
* when interrupted, but there's no good way of recovering the elapsed
* time that's worth the hassle.
*/
do {
tv.tv_sec = timeout;
tv.tv_usec = 0;
FD_ZERO(&set);
FD_SET(fd, &set);
status = select(fd + 1, NULL, &set, NULL, &tv);
} while (status < 0 && socket_errno == EINTR);
/*
* If we timed out, set errno appropriately. If the connection completes,
* retrieve the actual status from the socket.
*/
if (status == 0 && !FD_ISSET(fd, &set)) {
status = -1;
socket_set_errno(ETIMEDOUT);
} else if (status > 0 && FD_ISSET(fd, &set)) {
length = sizeof(err);
status = getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &length);
if (status == 0) {
status = (err == 0) ? 0 : -1;
socket_set_errno(err);
}
}
return status;
}
/*
* Given a linked list of addrinfo structs representing the remote service,
* try to create a local socket and connect to that service. Takes an
* optional source address. Try each address in turn until one of them
* connects. Returns the file descriptor of the open socket on success, or
* INVALID_SOCKET on failure. Tries to leave the reason for the failure in
* errno.
*/
socket_type
network_connect(const struct addrinfo *ai, const char *source, time_t timeout)
{
socket_type fd = INVALID_SOCKET;
int oerrno, status;
for (status = -1; status != 0 && ai != NULL; ai = ai->ai_next) {
if (fd != INVALID_SOCKET)
socket_close(fd);
fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
if (fd == INVALID_SOCKET)
continue;
if (!network_source(fd, ai->ai_family, source))
continue;
if (timeout == 0)
status = connect(fd, ai->ai_addr, ai->ai_addrlen);
else {
fdflag_nonblocking(fd, true);
status = connect(fd, ai->ai_addr, ai->ai_addrlen);
if (status < 0 && socket_errno == EINPROGRESS)
status = connect_wait(fd, timeout);
oerrno = socket_errno;
fdflag_nonblocking(fd, false);
socket_set_errno(oerrno);
}
}
if (status == 0)
return fd;
else {
if (fd != INVALID_SOCKET) {
oerrno = socket_errno;
socket_close(fd);
socket_set_errno(oerrno);
}
return INVALID_SOCKET;
}
}
/*
* Like network_connect, but takes a host and a port instead of an addrinfo
* struct list. Returns the file descriptor of the open socket on success, or
* INVALID_SOCKET on failure. If getaddrinfo fails, errno may not be set to
* anything useful.
*/
socket_type
network_connect_host(const char *host, unsigned short port,
const char *source, time_t timeout)
{
struct addrinfo hints, *ai;
char portbuf[16];
socket_type fd;
int status, oerrno;
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
status = snprintf(portbuf, sizeof(portbuf), "%hu", port);
if (status > 0 && (size_t) status > sizeof(portbuf)) {
status = -1;
socket_set_errno_einval();
}
if (status < 0)
return INVALID_SOCKET;
if (getaddrinfo(host, portbuf, &hints, &ai) != 0)
return INVALID_SOCKET;
fd = network_connect(ai, source, timeout);
oerrno = socket_errno;
freeaddrinfo(ai);
socket_set_errno(oerrno);
return fd;
}
/*
* Create a new socket of the specified domain and type and do the binding as
* if we were a regular client socket, but then return before connecting.
* Returns the file descriptor of the open socket on success, or
* INVALID_SOCKET on failure. Intended primarily for the use of clients that
* will then go on to do a non-blocking connect.
*/
socket_type
network_client_create(int domain, int type, const char *source)
{
socket_type fd;
int oerrno;
fd = socket(domain, type, 0);
if (fd == INVALID_SOCKET)
return INVALID_SOCKET;
if (!network_source(fd, domain, source)) {
oerrno = socket_errno;
socket_close(fd);
socket_set_errno(oerrno);
return INVALID_SOCKET;
}
return fd;
}
/*
* Equivalent to read, but reads all the available data up to the buffer
* length, using multiple reads if needed and handling EINTR and EAGAIN. If
* we get EOF before we get enough data, set the socket errno to EPIPE.
*/
static ssize_t
socket_xread(socket_type fd, void *buffer, size_t size)
{
size_t total;
ssize_t status;
int count = 0;
/* Abort the read if we try 100 times with no forward progress. */
for (total = 0, status = 0; total < size; total += status) {
if (++count > 100)
break;
status = socket_read(fd, (char *) buffer + total, size - total);
if (status > 0)
count = 0;
else if (status == 0)
break;
else {
if ((socket_errno != EINTR) && (socket_errno != EAGAIN))
break;
status = 0;
}
}
if (status == 0 && total < size)
socket_set_errno(EPIPE);
return (total < size) ? -1 : (ssize_t) total;
}
/*
* Read the specified number of bytes from the network, enforcing a timeout
* (in seconds). We use select to wait for data to become available and then
* keep reading until either we time out or we've gotten all the data we're
* looking for. timeout may be 0 to never time out. Return true on success
* and false (setting socket_errno) on failure.
*/
bool
network_read(socket_type fd, void *buffer, size_t total, time_t timeout)
{
time_t start, now;
fd_set set;
struct timeval tv;
size_t got = 0;
ssize_t status;
/* If there's no timeout, do this the easy way. */
if (timeout == 0)
return (socket_xread(fd, buffer, total) >= 0);
/*
* The hard way. We try to apply the timeout on the whole read. If
* either select or read fails with EINTR, restart the loop, and rely on
* the overall timeout to limit how long we wait without forward
* progress.
*/
start = time(NULL);
now = start;
do {
FD_ZERO(&set);
FD_SET(fd, &set);
tv.tv_sec = timeout - (now - start);
if (tv.tv_sec < 1)
tv.tv_sec = 1;
tv.tv_usec = 0;
status = select(fd + 1, &set, NULL, NULL, &tv);
if (status < 0) {
if (socket_errno == EINTR)
continue;
return false;
} else if (status == 0) {
socket_set_errno(ETIMEDOUT);
return false;
}
status = socket_read(fd, (char *) buffer + got, total - got);
if (status < 0) {
if (socket_errno == EINTR)
continue;
return false;
} else if (status == 0) {
socket_set_errno(EPIPE);
return false;
}
got += status;
if (got == total)
return true;
now = time(NULL);
} while (now - start < timeout);
socket_set_errno(ETIMEDOUT);
return false;
}
/*
* Write the specified number of bytes from the network, enforcing a timeout
* (in seconds). We use select to wait for the socket to become available and
* then keep reading until either we time out or we've sent all the data.
* timeout may be 0 to never time out. Return true on success and false
* (setting socket_errno) on failure.
*/
bool
network_write(socket_type fd, const void *buffer, size_t total, time_t timeout)
{
time_t start, now;
fd_set set;
struct timeval tv;
size_t sent = 0;
ssize_t status;
int err;
/* If there's no timeout, do this the easy way. */
if (timeout == 0)
return (socket_xwrite(fd, buffer, total) >= 0);
/* The hard way. We try to apply the timeout on the whole write. If
* either select or read fails with EINTR, restart the loop, and rely on
* the overall timeout to limit how long we wait without forward progress.
*/
fdflag_nonblocking(fd, true);
start = time(NULL);
now = start;
do {
FD_ZERO(&set);
FD_SET(fd, &set);
tv.tv_sec = timeout - (now - start);
if (tv.tv_sec < 1)
tv.tv_sec = 1;
tv.tv_usec = 0;
status = select(fd + 1, NULL, &set, NULL, &tv);
if (status < 0) {
if (socket_errno == EINTR)
continue;
goto fail;
} else if (status == 0) {
socket_set_errno(ETIMEDOUT);
goto fail;
}
status = socket_write(fd, (const char *) buffer + sent, total - sent);
if (status < 0) {
if (socket_errno == EINTR)
continue;
goto fail;
}
sent += status;
if (sent == total) {
fdflag_nonblocking(fd, false);
return true;
}
now = time(NULL);
} while (now - start < timeout);
socket_set_errno(ETIMEDOUT);
fail:
err = socket_errno;
fdflag_nonblocking(fd, false);
socket_set_errno(err);
return false;
}
/*
* Print an ASCII representation of the address of the given sockaddr into the
* provided buffer. This buffer must hold at least INET_ADDRSTRLEN characters
* for IPv4 addresses and INET6_ADDRSTRLEN characters for IPv6, so generally
* it should always be as large as the latter. Returns success or failure.
*/
bool
network_sockaddr_sprint(char *dst, size_t size, const struct sockaddr *addr)
{
const char *result;
#ifdef HAVE_INET6
if (addr->sa_family == AF_INET6) {
const struct sockaddr_in6 *sin6;
sin6 = (const struct sockaddr_in6 *) (const void *) addr;
if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
struct in_addr in;
memcpy(&in, sin6->sin6_addr.s6_addr + 12, sizeof(in));
result = inet_ntop(AF_INET, &in, dst, size);
} else
result = inet_ntop(AF_INET6, &sin6->sin6_addr, dst, size);
return (result != NULL);
}
#endif
if (addr->sa_family == AF_INET) {
const struct sockaddr_in *sin;
sin = (const struct sockaddr_in *) (const void *) addr;
result = inet_ntop(AF_INET, &sin->sin_addr, dst, size);
return (result != NULL);
} else {
socket_set_errno(EAFNOSUPPORT);
return false;
}
}
/*
* Compare the addresses from two sockaddrs and see whether they're equal.
* IPv4 addresses that have been mapped to IPv6 addresses compare equal to the
* corresponding IPv4 address.
*/
bool
network_sockaddr_equal(const struct sockaddr *a, const struct sockaddr *b)
{
const struct sockaddr_in *a4;
const struct sockaddr_in *b4;
#ifdef HAVE_INET6
const struct sockaddr_in6 *a6;
const struct sockaddr_in6 *b6;
const struct sockaddr *tmp;
#endif
a4 = (const struct sockaddr_in *) (const void *) a;
b4 = (const struct sockaddr_in *) (const void *) b;
#ifdef HAVE_INET6
a6 = (const struct sockaddr_in6 *) (const void *) a;
b6 = (const struct sockaddr_in6 *) (const void *) b;
if (a->sa_family == AF_INET && b->sa_family == AF_INET6) {
tmp = a;
a = b;
b = tmp;
a6 = (const struct sockaddr_in6 *) (const void *) a;
b4 = (const struct sockaddr_in *) (const void *) b;
}
if (a->sa_family == AF_INET6) {
if (b->sa_family == AF_INET6)
return IN6_ARE_ADDR_EQUAL(&a6->sin6_addr, &b6->sin6_addr);
else if (b->sa_family != AF_INET)
return false;
else if (!IN6_IS_ADDR_V4MAPPED(&a6->sin6_addr))
return false;
else {
struct in_addr in;
memcpy(&in, a6->sin6_addr.s6_addr + 12, sizeof(in));
return (in.s_addr == b4->sin_addr.s_addr);
}
}
#endif
if (a->sa_family != AF_INET || b->sa_family != AF_INET)
return false;
return (a4->sin_addr.s_addr == b4->sin_addr.s_addr);
}
/*
* Returns the port of a sockaddr or 0 on error.
*/
unsigned short
network_sockaddr_port(const struct sockaddr *sa)
{
const struct sockaddr_in *sin;
#ifdef HAVE_INET6
const struct sockaddr_in6 *sin6;
if (sa->sa_family == AF_INET6) {
sin6 = (const struct sockaddr_in6 *) (const void *) sa;
return htons(sin6->sin6_port);
}
#endif
if (sa->sa_family != AF_INET)
return 0;
else {
sin = (const struct sockaddr_in *) (const void *) sa;
return htons(sin->sin_port);
}
}
/*
* Compare two addresses given as strings, applying an optional mask. Returns
* true if the addresses are equal modulo the mask and false otherwise,
* including on syntax errors in the addresses or mask specification.
*/
bool
network_addr_match(const char *a, const char *b, const char *mask)
{
struct in_addr a4, b4, tmp;
unsigned long cidr;
char *end;
unsigned int i;
unsigned long bits, addr_mask;
#ifdef HAVE_INET6
struct in6_addr a6, b6;
#endif
/*
* AIX 7.1 treats the empty string as equivalent to 0.0.0.0 and allows it
* to match, but it's too easy to get the empty string from some sort of
* syntax error. Special-case the empty string to always return false.
*/
if (a[0] == '\0' || b[0] == '\0')
return false;
/*
* If the addresses are IPv4, the mask may be in one of two forms. It can
* either be a traditional mask, like 255.255.0.0, or it can be a CIDR
* subnet designation, like 16. (The caller should have already removed
* the slash separating it from the address.)
*/
if (inet_aton(a, &a4) && inet_aton(b, &b4)) {
if (mask == NULL)
addr_mask = htonl(0xffffffffUL);
else if (strchr(mask, '.') == NULL) {
cidr = strtoul(mask, &end, 10);
if (cidr > 32 || *end != '\0')
return false;
for (bits = 0, i = 0; i < cidr; i++)
bits |= (1UL << (31 - i));
addr_mask = htonl(bits);
} else if (inet_aton(mask, &tmp))
addr_mask = tmp.s_addr;
else
return false;
return (a4.s_addr & addr_mask) == (b4.s_addr & addr_mask);
}
#ifdef HAVE_INET6
/*
* Otherwise, if the address is IPv6, the mask is required to be a CIDR
* subnet designation.
*/
if (!inet_pton(AF_INET6, a, &a6) || !inet_pton(AF_INET6, b, &b6))
return false;
if (mask == NULL)
cidr = 128;
else {
cidr = strtoul(mask, &end, 10);
if (cidr > 128 || *end != '\0')
return false;
}
for (i = 0; i * 8 < cidr; i++) {
if ((i + 1) * 8 <= cidr) {
if (a6.s6_addr[i] != b6.s6_addr[i])
return false;
} else {
for (addr_mask = 0, bits = 0; bits < cidr % 8; bits++)
addr_mask |= (1UL << (7 - bits));
if ((a6.s6_addr[i] & addr_mask) != (b6.s6_addr[i] & addr_mask))
return false;
}
}
return true;
#else
return false;
#endif
}
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