mpd/src/listen.c

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/* the Music Player Daemon (MPD)
* Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com)
* This project's homepage is: http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "listen.h"
#include "client.h"
#include "conf.h"
#include "log.h"
#include "utils.h"
#include "os_compat.h"
#include "../config.h"
#define MAXHOSTNAME 1024
#define ALLOW_REUSE 1
#define DEFAULT_PORT 6600
#define BINDERROR() do { \
FATAL("unable to bind port %u: %s\n" \
"maybe MPD is still running?\n", \
port, strerror(errno)); \
} while (0);
static int *listenSockets;
static int numberOfListenSockets;
int boundPort;
/*
* redirect stdin to /dev/null to work around a libao bug
* there are likely other bugs in other libraries (and even our code!)
* that check for fd > 0, so it's easiest to just keep
* fd = 0 == /dev/null for now...
*/
static void redirect_stdin(void)
{
int fd, st;
struct stat ss;
if ((st = fstat(STDIN_FILENO, &ss)) < 0) {
if ((fd = open("/dev/null", O_RDONLY) > 0)) {
DEBUG("stdin closed, and could not open /dev/null "
"as fd=0, some external library bugs "
"may be exposed...\n");
close(fd);
}
return;
}
if (!isatty(STDIN_FILENO))
return;
if ((fd = open("/dev/null", O_RDONLY)) < 0)
FATAL("failed to open /dev/null %s\n", strerror(errno));
if (dup2(fd, STDIN_FILENO) < 0)
FATAL("dup2 stdin: %s\n", strerror(errno));
}
static int establishListen(int pf, const struct sockaddr *addrp,
socklen_t addrlen)
{
int sock;
int allowReuse = ALLOW_REUSE;
#ifdef HAVE_STRUCT_UCRED
int passcred = 1;
#endif
if ((sock = socket(pf, SOCK_STREAM, 0)) < 0)
FATAL("socket < 0\n");
if (set_nonblocking(sock) < 0) {
FATAL("problems setting nonblocking on listen socket: %s\n",
strerror(errno));
}
if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char *)&allowReuse,
sizeof(allowReuse)) < 0) {
FATAL("problems setsockopt'ing: %s\n", strerror(errno));
}
if (bind(sock, addrp, addrlen) < 0) {
close(sock);
return -1;
}
if (listen(sock, 5) < 0)
FATAL("problems listen'ing: %s\n", strerror(errno));
#ifdef HAVE_STRUCT_UCRED
setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &passcred, sizeof(passcred));
#endif
numberOfListenSockets++;
listenSockets =
xrealloc(listenSockets, sizeof(int) * numberOfListenSockets);
listenSockets[numberOfListenSockets - 1] = sock;
return 0;
}
static void parseListenConfigParam(unsigned int port, ConfigParam * param)
{
const struct sockaddr *addrp;
socklen_t addrlen;
#ifdef HAVE_TCP
struct sockaddr_in sin4;
#ifdef HAVE_IPV6
struct sockaddr_in6 sin6;
int useIpv6 = ipv6Supported();
memset(&sin6, 0, sizeof(struct sockaddr_in6));
sin6.sin6_port = htons(port);
sin6.sin6_family = AF_INET6;
#endif
memset(&sin4, 0, sizeof(struct sockaddr_in));
sin4.sin_port = htons(port);
sin4.sin_family = AF_INET;
#endif /* HAVE_TCP */
if (!param || 0 == strcmp(param->value, "any")) {
#ifdef HAVE_TCP
DEBUG("binding to any address\n");
#ifdef HAVE_IPV6
if (useIpv6) {
sin6.sin6_addr = in6addr_any;
addrp = (const struct sockaddr *)&sin6;
addrlen = sizeof(struct sockaddr_in6);
if (establishListen(PF_INET6, addrp, addrlen) < 0)
BINDERROR();
}
#endif
sin4.sin_addr.s_addr = INADDR_ANY;
addrp = (const struct sockaddr *)&sin4;
addrlen = sizeof(struct sockaddr_in);
#ifdef HAVE_IPV6
if ((establishListen(PF_INET, addrp, addrlen) < 0) && !useIpv6) {
#else
if (establishListen(PF_INET, addrp, addrlen) < 0) {
#endif
BINDERROR();
}
#else /* HAVE_TCP */
FATAL("TCP support is disabled\n");
#endif /* HAVE_TCP */
#ifdef HAVE_UN
} else if (param->value[0] == '/') {
size_t path_length;
struct sockaddr_un s_un;
path_length = strlen(param->value);
if (path_length >= sizeof(s_un.sun_path))
FATAL("unix socket path is too long\n");
unlink(param->value);
s_un.sun_family = AF_UNIX;
memcpy(s_un.sun_path, param->value, path_length + 1);
addrp = (const struct sockaddr *)&s_un;
addrlen = sizeof(s_un);
if (establishListen(PF_UNIX, addrp, addrlen) < 0)
FATAL("unable to bind to %s: %s\n",
param->value, strerror(errno));
/* allow everybody to connect */
chmod(param->value, 0666);
#endif /* HAVE_UN */
} else {
#ifdef HAVE_TCP
struct addrinfo hints, *ai, *i;
char service[20];
int ret;
DEBUG("binding to address for %s\n", param->value);
memset(&hints, 0, sizeof(hints));
hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG;
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
snprintf(service, sizeof(service), "%u", port);
ret = getaddrinfo(param->value, service, &hints, &ai);
if (ret != 0)
FATAL("can't lookup host \"%s\" at line %i: %s\n",
param->value, param->line, gai_strerror(ret));
for (i = ai; i != NULL; i = i->ai_next)
if (establishListen(i->ai_family, i->ai_addr,
i->ai_addrlen) < 0)
BINDERROR();
freeaddrinfo(ai);
#else /* HAVE_TCP */
FATAL("TCP support is disabled\n");
#endif /* HAVE_TCP */
}
}
void listenOnPort(void)
{
int port = DEFAULT_PORT;
ConfigParam *param = getNextConfigParam(CONF_BIND_TO_ADDRESS, NULL);
ConfigParam *portParam = getConfigParam(CONF_PORT);
if (portParam) {
char *test;
port = strtol(portParam->value, &test, 10);
if (port <= 0 || *test != '\0') {
FATAL("%s \"%s\" specified at line %i is not a "
"positive integer", CONF_PORT,
portParam->value, portParam->line);
}
}
boundPort = port;
redirect_stdin();
do {
parseListenConfigParam(port, param);
} while ((param = getNextConfigParam(CONF_BIND_TO_ADDRESS, param)));
}
void addListenSocketsToFdSet(fd_set * fds, int *fdmax)
{
int i;
for (i = 0; i < numberOfListenSockets; i++) {
FD_SET(listenSockets[i], fds);
if (listenSockets[i] > *fdmax)
*fdmax = listenSockets[i];
}
}
void closeAllListenSockets(void)
{
int i;
DEBUG("closeAllListenSockets called\n");
for (i = 0; i < numberOfListenSockets; i++) {
DEBUG("closing listen socket %i\n", i);
while (close(listenSockets[i]) < 0 && errno == EINTR) ;
}
freeAllListenSockets();
}
void freeAllListenSockets(void)
{
numberOfListenSockets = 0;
free(listenSockets);
listenSockets = NULL;
}
static int get_remote_uid(int fd)
{
#ifdef HAVE_STRUCT_UCRED
struct ucred cred;
socklen_t len = sizeof (cred);
if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cred, &len) < 0)
return 0;
return cred.uid;
#else
(void)fd;
return -1;
#endif
}
void getConnections(fd_set * fds)
{
int i;
int fd = 0;
struct sockaddr sockAddr;
socklen_t socklen = sizeof(sockAddr);
for (i = 0; i < numberOfListenSockets; i++) {
if (FD_ISSET(listenSockets[i], fds)) {
if ((fd = accept(listenSockets[i], &sockAddr, &socklen))
>= 0) {
client_new(fd, &sockAddr, get_remote_uid(fd));
} else if (fd < 0
&& (errno != EAGAIN && errno != EINTR)) {
ERROR("Problems accept()'ing\n");
}
}
}
}