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evutil.c
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evutil.c
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/*
* Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "event2/event-config.h"
#include "evconfig-private.h"
#ifdef _WIN32
#include <winsock2.h>
#include <ws2tcpip.h>
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#undef WIN32_LEAN_AND_MEAN
#include <io.h>
#include <tchar.h>
#undef _WIN32_WINNT
/* For structs needed by GetAdaptersAddresses */
#define _WIN32_WINNT 0x0501
#include <iphlpapi.h>
#endif
#include <sys/types.h>
#ifdef EVENT__HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef EVENT__HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef EVENT__HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef EVENT__HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
#ifdef EVENT__HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef EVENT__HAVE_NETINET_IN6_H
#include <netinet/in6.h>
#endif
#ifdef EVENT__HAVE_NETINET_TCP_H
#include <netinet/tcp.h>
#endif
#ifdef EVENT__HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#if !defined(EVENT__HAVE_NANOSLEEP) && !defined(EVENT_HAVE_USLEEP) && \
!defined(_WIN32)
#include <sys/select.h>
#endif
#ifndef EVENT__HAVE_GETTIMEOFDAY
#include <sys/timeb.h>
#endif
#include <time.h>
#include <sys/stat.h>
#ifdef EVENT__HAVE_IFADDRS_H
#include <ifaddrs.h>
#endif
#include "event2/util.h"
#include "util-internal.h"
#include "log-internal.h"
#include "mm-internal.h"
#include "strlcpy-internal.h"
#include "ipv6-internal.h"
#ifdef _WIN32
#define open _open
#define read _read
#define close _close
#define fstat _fstati64
#define stat _stati64
#define mode_t int
#endif
int
evutil_open_closeonexec_(const char *pathname, int flags, unsigned mode)
{
int fd;
#ifdef O_CLOEXEC
if (flags & O_CREAT)
fd = open(pathname, flags|O_CLOEXEC, (mode_t)mode);
else
fd = open(pathname, flags|O_CLOEXEC);
if (fd >= 0 || errno == EINVAL)
return fd;
/* If we got an EINVAL, fall through and try without O_CLOEXEC */
#endif
if (flags & O_CREAT)
fd = open(pathname, flags, (mode_t)mode);
else
fd = open(pathname, flags);
if (fd < 0)
return -1;
#if defined(FD_CLOEXEC)
if (fcntl(fd, F_SETFD, FD_CLOEXEC) < 0)
return -1;
#endif
return fd;
}
/**
Read the contents of 'filename' into a newly allocated NUL-terminated
string. Set *content_out to hold this string, and *len_out to hold its
length (not including the appended NUL). If 'is_binary', open the file in
binary mode.
Returns 0 on success, -1 if the open fails, and -2 for all other failures.
Used internally only; may go away in a future version.
*/
int
evutil_read_file_(const char *filename, char **content_out, size_t *len_out,
int is_binary)
{
int fd, r;
struct stat st;
char *mem;
size_t read_so_far=0;
int mode = O_RDONLY;
EVUTIL_ASSERT(content_out);
EVUTIL_ASSERT(len_out);
*content_out = NULL;
*len_out = 0;
#ifdef O_BINARY
if (is_binary)
mode |= O_BINARY;
#endif
fd = evutil_open_closeonexec_(filename, mode, 0);
if (fd < 0)
return -1;
if (fstat(fd, &st) || st.st_size < 0 ||
st.st_size > EV_SSIZE_MAX-1 ) {
close(fd);
return -2;
}
mem = mm_malloc((size_t)st.st_size + 1);
if (!mem) {
close(fd);
return -2;
}
read_so_far = 0;
#ifdef _WIN32
#define N_TO_READ(x) ((x) > INT_MAX) ? INT_MAX : ((int)(x))
#else
#define N_TO_READ(x) (x)
#endif
while ((r = read(fd, mem+read_so_far, N_TO_READ(st.st_size - read_so_far))) > 0) {
read_so_far += r;
if (read_so_far >= (size_t)st.st_size)
break;
EVUTIL_ASSERT(read_so_far < (size_t)st.st_size);
}
close(fd);
if (r < 0) {
mm_free(mem);
return -2;
}
mem[read_so_far] = 0;
*len_out = read_so_far;
*content_out = mem;
return 0;
}
int
evutil_socketpair(int family, int type, int protocol, evutil_socket_t fd[2])
{
#ifndef _WIN32
return socketpair(family, type, protocol, fd);
#else
return evutil_ersatz_socketpair_(family, type, protocol, fd);
#endif
}
int
evutil_ersatz_socketpair_(int family, int type, int protocol,
evutil_socket_t fd[2])
{
/* This code is originally from Tor. Used with permission. */
/* This socketpair does not work when localhost is down. So
* it's really not the same thing at all. But it's close enough
* for now, and really, when localhost is down sometimes, we
* have other problems too.
*/
#ifdef _WIN32
#define ERR(e) WSA##e
#else
#define ERR(e) e
#endif
evutil_socket_t listener = -1;
evutil_socket_t connector = -1;
evutil_socket_t acceptor = -1;
struct sockaddr_in listen_addr;
struct sockaddr_in connect_addr;
ev_socklen_t size;
int saved_errno = -1;
if (protocol
|| (family != AF_INET
#ifdef AF_UNIX
&& family != AF_UNIX
#endif
)) {
EVUTIL_SET_SOCKET_ERROR(ERR(EAFNOSUPPORT));
return -1;
}
if (!fd) {
EVUTIL_SET_SOCKET_ERROR(ERR(EINVAL));
return -1;
}
listener = socket(AF_INET, type, 0);
if (listener < 0)
return -1;
memset(&listen_addr, 0, sizeof(listen_addr));
listen_addr.sin_family = AF_INET;
listen_addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
listen_addr.sin_port = 0; /* kernel chooses port. */
if (bind(listener, (struct sockaddr *) &listen_addr, sizeof (listen_addr))
== -1)
goto tidy_up_and_fail;
if (listen(listener, 1) == -1)
goto tidy_up_and_fail;
connector = socket(AF_INET, type, 0);
if (connector < 0)
goto tidy_up_and_fail;
/* We want to find out the port number to connect to. */
size = sizeof(connect_addr);
if (getsockname(listener, (struct sockaddr *) &connect_addr, &size) == -1)
goto tidy_up_and_fail;
if (size != sizeof (connect_addr))
goto abort_tidy_up_and_fail;
if (connect(connector, (struct sockaddr *) &connect_addr,
sizeof(connect_addr)) == -1)
goto tidy_up_and_fail;
size = sizeof(listen_addr);
acceptor = accept(listener, (struct sockaddr *) &listen_addr, &size);
if (acceptor < 0)
goto tidy_up_and_fail;
if (size != sizeof(listen_addr))
goto abort_tidy_up_and_fail;
evutil_closesocket(listener);
/* Now check we are talking to ourself by matching port and host on the
two sockets. */
if (getsockname(connector, (struct sockaddr *) &connect_addr, &size) == -1)
goto tidy_up_and_fail;
if (size != sizeof (connect_addr)
|| listen_addr.sin_family != connect_addr.sin_family
|| listen_addr.sin_addr.s_addr != connect_addr.sin_addr.s_addr
|| listen_addr.sin_port != connect_addr.sin_port)
goto abort_tidy_up_and_fail;
fd[0] = connector;
fd[1] = acceptor;
return 0;
abort_tidy_up_and_fail:
saved_errno = ERR(ECONNABORTED);
tidy_up_and_fail:
if (saved_errno < 0)
saved_errno = EVUTIL_SOCKET_ERROR();
if (listener != -1)
evutil_closesocket(listener);
if (connector != -1)
evutil_closesocket(connector);
if (acceptor != -1)
evutil_closesocket(acceptor);
EVUTIL_SET_SOCKET_ERROR(saved_errno);
return -1;
#undef ERR
}
int
evutil_make_socket_nonblocking(evutil_socket_t fd)
{
#ifdef _WIN32
{
u_long nonblocking = 1;
if (ioctlsocket(fd, FIONBIO, &nonblocking) == SOCKET_ERROR) {
event_sock_warn(fd, "fcntl(%d, F_GETFL)", (int)fd);
return -1;
}
}
#else
{
int flags;
if ((flags = fcntl(fd, F_GETFL, NULL)) < 0) {
event_warn("fcntl(%d, F_GETFL)", fd);
return -1;
}
if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1) {
event_warn("fcntl(%d, F_SETFL)", fd);
return -1;
}
}
#endif
return 0;
}
/* Faster version of evutil_make_socket_nonblocking for internal use.
*
* Requires that no F_SETFL flags were previously set on the fd.
*/
static int
evutil_fast_socket_nonblocking(evutil_socket_t fd)
{
#ifdef _WIN32
return evutil_make_socket_nonblocking(fd);
#else
if (fcntl(fd, F_SETFL, O_NONBLOCK) == -1) {
event_warn("fcntl(%d, F_SETFL)", fd);
return -1;
}
return 0;
#endif
}
int
evutil_make_listen_socket_reuseable(evutil_socket_t sock)
{
#ifndef _WIN32
int one = 1;
/* REUSEADDR on Unix means, "don't hang on to this address after the
* listener is closed." On Windows, though, it means "don't keep other
* processes from binding to this address while we're using it. */
return setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void*) &one,
(ev_socklen_t)sizeof(one));
#else
return 0;
#endif
}
int
evutil_make_tcp_listen_socket_deferred(evutil_socket_t sock)
{
#if defined(EVENT__HAVE_NETINET_TCP_H) && defined(TCP_DEFER_ACCEPT)
int one = 1;
/* TCP_DEFER_ACCEPT tells the kernel to call defer accept() only after data
* has arrived and ready to read */
return setsockopt(sock, IPPROTO_TCP, TCP_DEFER_ACCEPT, &one,
(ev_socklen_t)sizeof(one));
#endif
return 0;
}
int
evutil_make_socket_closeonexec(evutil_socket_t fd)
{
#if !defined(_WIN32) && defined(EVENT__HAVE_SETFD)
int flags;
if ((flags = fcntl(fd, F_GETFD, NULL)) < 0) {
event_warn("fcntl(%d, F_GETFD)", fd);
return -1;
}
if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) == -1) {
event_warn("fcntl(%d, F_SETFD)", fd);
return -1;
}
#endif
return 0;
}
/* Faster version of evutil_make_socket_closeonexec for internal use.
*
* Requires that no F_SETFD flags were previously set on the fd.
*/
static int
evutil_fast_socket_closeonexec(evutil_socket_t fd)
{
#if !defined(_WIN32) && defined(EVENT__HAVE_SETFD)
if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1) {
event_warn("fcntl(%d, F_SETFD)", fd);
return -1;
}
#endif
return 0;
}
int
evutil_closesocket(evutil_socket_t sock)
{
#ifndef _WIN32
return close(sock);
#else
return closesocket(sock);
#endif
}
ev_int64_t
evutil_strtoll(const char *s, char **endptr, int base)
{
#ifdef EVENT__HAVE_STRTOLL
return (ev_int64_t)strtoll(s, endptr, base);
#elif EVENT__SIZEOF_LONG == 8
return (ev_int64_t)strtol(s, endptr, base);
#elif defined(_WIN32) && defined(_MSC_VER) && _MSC_VER < 1300
/* XXXX on old versions of MS APIs, we only support base
* 10. */
ev_int64_t r;
if (base != 10)
return 0;
r = (ev_int64_t) _atoi64(s);
while (isspace(*s))
++s;
if (*s == '-')
++s;
while (isdigit(*s))
++s;
if (endptr)
*endptr = (char*) s;
return r;
#elif defined(_WIN32)
return (ev_int64_t) _strtoi64(s, endptr, base);
#elif defined(EVENT__SIZEOF_LONG_LONG) && EVENT__SIZEOF_LONG_LONG == 8
long long r;
int n;
if (base != 10 && base != 16)
return 0;
if (base == 10) {
n = sscanf(s, "%lld", &r);
} else {
unsigned long long ru=0;
n = sscanf(s, "%llx", &ru);
if (ru > EV_INT64_MAX)
return 0;
r = (long long) ru;
}
if (n != 1)
return 0;
while (EVUTIL_ISSPACE_(*s))
++s;
if (*s == '-')
++s;
if (base == 10) {
while (EVUTIL_ISDIGIT_(*s))
++s;
} else {
while (EVUTIL_ISXDIGIT_(*s))
++s;
}
if (endptr)
*endptr = (char*) s;
return r;
#else
#error "I don't know how to parse 64-bit integers."
#endif
}
#ifndef EVENT__HAVE_GETTIMEOFDAY
/* No gettimeofday; this must be windows. */
int
evutil_gettimeofday(struct timeval *tv, struct timezone *tz)
{
#ifdef _MSC_VER
#define U64_LITERAL(n) n##ui64
#else
#define U64_LITERAL(n) n##llu
#endif
/* Conversion logic taken from Tor, which in turn took it
* from Perl. GetSystemTimeAsFileTime returns its value as
* an unaligned (!) 64-bit value containing the number of
* 100-nanosecond intervals since 1 January 1601 UTC. */
#define EPOCH_BIAS U64_LITERAL(116444736000000000)
#define UNITS_PER_SEC U64_LITERAL(10000000)
#define USEC_PER_SEC U64_LITERAL(1000000)
#define UNITS_PER_USEC U64_LITERAL(10)
union {
FILETIME ft_ft;
ev_uint64_t ft_64;
} ft;
if (tv == NULL)
return -1;
GetSystemTimeAsFileTime(&ft.ft_ft);
if (EVUTIL_UNLIKELY(ft.ft_64 < EPOCH_BIAS)) {
/* Time before the unix epoch. */
return -1;
}
ft.ft_64 -= EPOCH_BIAS;
tv->tv_sec = (long) (ft.ft_64 / UNITS_PER_SEC);
tv->tv_usec = (long) ((ft.ft_64 / UNITS_PER_USEC) % USEC_PER_SEC);
return 0;
}
#endif
#ifdef _WIN32
int
evutil_socket_geterror(evutil_socket_t sock)
{
int optval, optvallen=sizeof(optval);
int err = WSAGetLastError();
if (err == WSAEWOULDBLOCK && sock >= 0) {
if (getsockopt(sock, SOL_SOCKET, SO_ERROR, (void*)&optval,
&optvallen))
return err;
if (optval)
return optval;
}
return err;
}
#endif
/* XXX we should use an enum here. */
/* 2 for connection refused, 1 for connected, 0 for not yet, -1 for error. */
int
evutil_socket_connect_(evutil_socket_t *fd_ptr, struct sockaddr *sa, int socklen)
{
int made_fd = 0;
if (*fd_ptr < 0) {
if ((*fd_ptr = socket(sa->sa_family, SOCK_STREAM, 0)) < 0)
goto err;
made_fd = 1;
if (evutil_make_socket_nonblocking(*fd_ptr) < 0) {
goto err;
}
}
if (connect(*fd_ptr, sa, socklen) < 0) {
int e = evutil_socket_geterror(*fd_ptr);
if (EVUTIL_ERR_CONNECT_RETRIABLE(e))
return 0;
if (EVUTIL_ERR_CONNECT_REFUSED(e))
return 2;
goto err;
} else {
return 1;
}
err:
if (made_fd) {
evutil_closesocket(*fd_ptr);
*fd_ptr = -1;
}
return -1;
}
/* Check whether a socket on which we called connect() is done
connecting. Return 1 for connected, 0 for not yet, -1 for error. In the
error case, set the current socket errno to the error that happened during
the connect operation. */
int
evutil_socket_finished_connecting_(evutil_socket_t fd)
{
int e;
ev_socklen_t elen = sizeof(e);
if (getsockopt(fd, SOL_SOCKET, SO_ERROR, (void*)&e, &elen) < 0)
return -1;
if (e) {
if (EVUTIL_ERR_CONNECT_RETRIABLE(e))
return 0;
EVUTIL_SET_SOCKET_ERROR(e);
return -1;
}
return 1;
}
#if (EVUTIL_AI_PASSIVE|EVUTIL_AI_CANONNAME|EVUTIL_AI_NUMERICHOST| \
EVUTIL_AI_NUMERICSERV|EVUTIL_AI_V4MAPPED|EVUTIL_AI_ALL| \
EVUTIL_AI_ADDRCONFIG) != \
(EVUTIL_AI_PASSIVE^EVUTIL_AI_CANONNAME^EVUTIL_AI_NUMERICHOST^ \
EVUTIL_AI_NUMERICSERV^EVUTIL_AI_V4MAPPED^EVUTIL_AI_ALL^ \
EVUTIL_AI_ADDRCONFIG)
#error "Some of our EVUTIL_AI_* flags seem to overlap with system AI_* flags"
#endif
/* We sometimes need to know whether we have an ipv4 address and whether we
have an ipv6 address. If 'have_checked_interfaces', then we've already done
the test. If 'had_ipv4_address', then it turns out we had an ipv4 address.
If 'had_ipv6_address', then it turns out we had an ipv6 address. These are
set by evutil_check_interfaces. */
static int have_checked_interfaces, had_ipv4_address, had_ipv6_address;
/* Macro: True iff the IPv4 address 'addr', in host order, is in 127.0.0.0/8
*/
#define EVUTIL_V4ADDR_IS_LOCALHOST(addr) (((addr)>>24) == 127)
/* Macro: True iff the IPv4 address 'addr', in host order, is a class D
* (multiclass) address.
*/
#define EVUTIL_V4ADDR_IS_CLASSD(addr) ((((addr)>>24) & 0xf0) == 0xe0)
static void
evutil_found_ifaddr(const struct sockaddr *sa)
{
const char ZEROES[] = "\x00\x00\x00\x00\x00\x00\x00\x00"
"\x00\x00\x00\x00\x00\x00\x00\x00";
if (sa->sa_family == AF_INET) {
const struct sockaddr_in *sin = (struct sockaddr_in *)sa;
ev_uint32_t addr = ntohl(sin->sin_addr.s_addr);
if (addr == 0 ||
EVUTIL_V4ADDR_IS_LOCALHOST(addr) ||
EVUTIL_V4ADDR_IS_CLASSD(addr)) {
/* Not actually a usable external address. */
} else {
event_debug(("Detected an IPv4 interface"));
had_ipv4_address = 1;
}
} else if (sa->sa_family == AF_INET6) {
const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
const unsigned char *addr =
(unsigned char*)sin6->sin6_addr.s6_addr;
if (!memcmp(addr, ZEROES, 8) ||
((addr[0] & 0xfe) == 0xfc) ||
(addr[0] == 0xfe && (addr[1] & 0xc0) == 0x80) ||
(addr[0] == 0xfe && (addr[1] & 0xc0) == 0xc0) ||
(addr[0] == 0xff)) {
/* This is a reserved, ipv4compat, ipv4map, loopback,
* link-local, multicast, or unspecified address. */
} else {
event_debug(("Detected an IPv6 interface"));
had_ipv6_address = 1;
}
}
}
#ifdef _WIN32
typedef ULONG (WINAPI *GetAdaptersAddresses_fn_t)(
ULONG, ULONG, PVOID, PIP_ADAPTER_ADDRESSES, PULONG);
#endif
static int
evutil_check_ifaddrs(void)
{
#if defined(EVENT__HAVE_GETIFADDRS)
/* Most free Unixy systems provide getifaddrs, which gives us a linked list
* of struct ifaddrs. */
struct ifaddrs *ifa = NULL;
const struct ifaddrs *i;
if (getifaddrs(&ifa) < 0) {
event_warn("Unable to call getifaddrs()");
return -1;
}
for (i = ifa; i; i = i->ifa_next) {
if (!i->ifa_addr)
continue;
evutil_found_ifaddr(i->ifa_addr);
}
freeifaddrs(ifa);
return 0;
#elif defined(_WIN32)
/* Windows XP began to provide GetAdaptersAddresses. Windows 2000 had a
"GetAdaptersInfo", but that's deprecated; let's just try
GetAdaptersAddresses and fall back to connect+getsockname.
*/
HANDLE lib = evutil_load_windows_system_library_(TEXT("ihplapi.dll"));
GetAdaptersAddresses_fn_t fn;
ULONG size, res;
IP_ADAPTER_ADDRESSES *addresses = NULL, *address;
int result = -1;
#define FLAGS (GAA_FLAG_SKIP_ANYCAST | \
GAA_FLAG_SKIP_MULTICAST | \
GAA_FLAG_SKIP_DNS_SERVER)
if (!lib)
goto done;
if (!(fn = (GetAdaptersAddresses_fn_t) GetProcAddress(lib, "GetAdaptersAddresses")))
goto done;
/* Guess how much space we need. */
size = 15*1024;
addresses = mm_malloc(size);
if (!addresses)
goto done;
res = fn(AF_UNSPEC, FLAGS, NULL, addresses, &size);
if (res == ERROR_BUFFER_OVERFLOW) {
/* we didn't guess that we needed enough space; try again */
mm_free(addresses);
addresses = mm_malloc(size);
if (!addresses)
goto done;
res = fn(AF_UNSPEC, FLAGS, NULL, addresses, &size);
}
if (res != NO_ERROR)
goto done;
for (address = addresses; address; address = address->Next) {
IP_ADAPTER_UNICAST_ADDRESS *a;
for (a = address->FirstUnicastAddress; a; a = a->Next) {
/* Yes, it's a linked list inside a linked list */
struct sockaddr *sa = a->Address.lpSockaddr;
evutil_found_ifaddr(sa);
}
}
result = 0;
done:
if (lib)
FreeLibrary(lib);
if (addresses)
mm_free(addresses);
return result;
#else
return -1;
#endif
}
/* Test whether we have an ipv4 interface and an ipv6 interface. Return 0 if
* the test seemed successful. */
static int
evutil_check_interfaces(int force_recheck)
{
evutil_socket_t fd = -1;
struct sockaddr_in sin, sin_out;
struct sockaddr_in6 sin6, sin6_out;
ev_socklen_t sin_out_len = sizeof(sin_out);
ev_socklen_t sin6_out_len = sizeof(sin6_out);
int r;
if (have_checked_interfaces && !force_recheck)
return 0;
if (evutil_check_ifaddrs() == 0) {
/* Use a nice sane interface, if this system has one. */
return 0;
}
/* Ugh. There was no nice sane interface. So to check whether we have
* an interface open for a given protocol, will try to make a UDP
* 'connection' to a remote host on the internet. We don't actually
* use it, so the address doesn't matter, but we want to pick one that
* keep us from using a host- or link-local interface. */
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_port = htons(53);
r = evutil_inet_pton(AF_INET, "18.244.0.188", &sin.sin_addr);
EVUTIL_ASSERT(r);
memset(&sin6, 0, sizeof(sin6));
sin6.sin6_family = AF_INET6;
sin6.sin6_port = htons(53);
r = evutil_inet_pton(AF_INET6, "2001:4860:b002::68", &sin6.sin6_addr);
EVUTIL_ASSERT(r);
memset(&sin_out, 0, sizeof(sin_out));
memset(&sin6_out, 0, sizeof(sin6_out));
/* XXX some errnos mean 'no address'; some mean 'not enough sockets'. */
if ((fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) >= 0 &&
connect(fd, (struct sockaddr*)&sin, sizeof(sin)) == 0 &&
getsockname(fd, (struct sockaddr*)&sin_out, &sin_out_len) == 0) {
/* We might have an IPv4 interface. */
evutil_found_ifaddr((struct sockaddr*) &sin_out);
}
if (fd >= 0)
evutil_closesocket(fd);
if ((fd = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP)) >= 0 &&
connect(fd, (struct sockaddr*)&sin6, sizeof(sin6)) == 0 &&
getsockname(fd, (struct sockaddr*)&sin6_out, &sin6_out_len) == 0) {
/* We might have an IPv6 interface. */
evutil_found_ifaddr((struct sockaddr*) &sin6_out);
}
if (fd >= 0)
evutil_closesocket(fd);
return 0;
}
/* Internal addrinfo flag. This one is set when we allocate the addrinfo from
* inside libevent. Otherwise, the built-in getaddrinfo() function allocated
* it, and we should trust what they said.
**/
#define EVUTIL_AI_LIBEVENT_ALLOCATED 0x80000000
/* Helper: construct a new addrinfo containing the socket address in
* 'sa', which must be a sockaddr_in or a sockaddr_in6. Take the
* socktype and protocol info from hints. If they weren't set, then
* allocate both a TCP and a UDP addrinfo.
*/
struct evutil_addrinfo *
evutil_new_addrinfo_(struct sockaddr *sa, ev_socklen_t socklen,
const struct evutil_addrinfo *hints)
{
struct evutil_addrinfo *res;
EVUTIL_ASSERT(hints);
if (hints->ai_socktype == 0 && hints->ai_protocol == 0) {
/* Indecisive user! Give them a UDP and a TCP. */
struct evutil_addrinfo *r1, *r2;
struct evutil_addrinfo tmp;
memcpy(&tmp, hints, sizeof(tmp));
tmp.ai_socktype = SOCK_STREAM; tmp.ai_protocol = IPPROTO_TCP;
r1 = evutil_new_addrinfo_(sa, socklen, &tmp);
if (!r1)
return NULL;
tmp.ai_socktype = SOCK_DGRAM; tmp.ai_protocol = IPPROTO_UDP;
r2 = evutil_new_addrinfo_(sa, socklen, &tmp);
if (!r2) {
evutil_freeaddrinfo(r1);
return NULL;
}
r1->ai_next = r2;
return r1;
}
/* We're going to allocate extra space to hold the sockaddr. */
res = mm_calloc(1,sizeof(struct evutil_addrinfo)+socklen);
if (!res)
return NULL;
res->ai_addr = (struct sockaddr*)
(((char*)res) + sizeof(struct evutil_addrinfo));
memcpy(res->ai_addr, sa, socklen);
res->ai_addrlen = socklen;
res->ai_family = sa->sa_family; /* Same or not? XXX */
res->ai_flags = EVUTIL_AI_LIBEVENT_ALLOCATED;
res->ai_socktype = hints->ai_socktype;
res->ai_protocol = hints->ai_protocol;
return res;
}
/* Append the addrinfo 'append' to the end of 'first', and return the start of
* the list. Either element can be NULL, in which case we return the element
* that is not NULL. */
struct evutil_addrinfo *
evutil_addrinfo_append_(struct evutil_addrinfo *first,
struct evutil_addrinfo *append)
{
struct evutil_addrinfo *ai = first;
if (!ai)
return append;
while (ai->ai_next)
ai = ai->ai_next;
ai->ai_next = append;
return first;
}
static int
parse_numeric_servname(const char *servname)
{
int n;
char *endptr=NULL;
n = (int) strtol(servname, &endptr, 10);
if (n>=0 && n <= 65535 && servname[0] && endptr && !endptr[0])
return n;
else
return -1;
}
/** Parse a service name in 'servname', which can be a decimal port.
* Return the port number, or -1 on error.
*/
static int
evutil_parse_servname(const char *servname, const char *protocol,
const struct evutil_addrinfo *hints)
{
int n = parse_numeric_servname(servname);
if (n>=0)
return n;
#if defined(EVENT__HAVE_GETSERVBYNAME) || defined(_WIN32)
if (!(hints->ai_flags & EVUTIL_AI_NUMERICSERV)) {
struct servent *ent = getservbyname(servname, protocol);
if (ent) {
return ntohs(ent->s_port);
}
}
#endif
return -1;
}
/* Return a string corresponding to a protocol number that we can pass to
* getservyname. */
static const char *
evutil_unparse_protoname(int proto)
{
switch (proto) {
case 0:
return NULL;
case IPPROTO_TCP:
return "tcp";
case IPPROTO_UDP:
return "udp";
#ifdef IPPROTO_SCTP
case IPPROTO_SCTP:
return "sctp";
#endif
default:
#ifdef EVENT__HAVE_GETPROTOBYNUMBER
{
struct protoent *ent = getprotobynumber(proto);
if (ent)
return ent->p_name;
}
#endif
return NULL;
}
}
static void
evutil_getaddrinfo_infer_protocols(struct evutil_addrinfo *hints)
{
/* If we can guess the protocol from the socktype, do so. */
if (!hints->ai_protocol && hints->ai_socktype) {
if (hints->ai_socktype == SOCK_DGRAM)
hints->ai_protocol = IPPROTO_UDP;
else if (hints->ai_socktype == SOCK_STREAM)
hints->ai_protocol = IPPROTO_TCP;
}
/* Set the socktype if it isn't set. */
if (!hints->ai_socktype && hints->ai_protocol) {
if (hints->ai_protocol == IPPROTO_UDP)
hints->ai_socktype = SOCK_DGRAM;
else if (hints->ai_protocol == IPPROTO_TCP)
hints->ai_socktype = SOCK_STREAM;
#ifdef IPPROTO_SCTP
else if (hints->ai_protocol == IPPROTO_SCTP)
hints->ai_socktype = SOCK_STREAM;
#endif
}
}
#if AF_UNSPEC != PF_UNSPEC
#error "I cannot build on a system where AF_UNSPEC != PF_UNSPEC"
#endif
/** Implements the part of looking up hosts by name that's common to both
* the blocking and nonblocking resolver:
* - Adjust 'hints' to have a reasonable socktype and protocol.
* - Look up the port based on 'servname', and store it in *portnum,
* - Handle the nodename==NULL case
* - Handle some invalid arguments cases.
* - Handle the cases where nodename is an IPv4 or IPv6 address.
*
* If we need the resolver to look up the hostname, we return
* EVUTIL_EAI_NEED_RESOLVE. Otherwise, we can completely implement
* getaddrinfo: we return 0 or an appropriate EVUTIL_EAI_* error, and
* set *res as getaddrinfo would.
*/
int
evutil_getaddrinfo_common_(const char *nodename, const char *servname,
struct evutil_addrinfo *hints, struct evutil_addrinfo **res, int *portnum)
{
int port = 0;
const char *pname;
if (nodename == NULL && servname == NULL)
return EVUTIL_EAI_NONAME;
/* We only understand 3 families */
if (hints->ai_family != PF_UNSPEC && hints->ai_family != PF_INET &&
hints->ai_family != PF_INET6)
return EVUTIL_EAI_FAMILY;
evutil_getaddrinfo_infer_protocols(hints);
/* Look up the port number and protocol, if possible. */
pname = evutil_unparse_protoname(hints->ai_protocol);