From 238909aaff10489fe538c8c54e3f82fe8a54b849 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Wed, 2 Jun 2010 04:37:40 +0200 Subject: [PATCH] systemd: add support for acquiring socket from systemd --- avahi-daemon/Makefile.am | 9 +- avahi-daemon/main.c | 10 +- avahi-daemon/sd-daemon.c | 448 +++++++++++++++++++++++++++++++++ avahi-daemon/sd-daemon.h | 257 +++++++++++++++++++ avahi-daemon/simple-protocol.c | 127 ++++++---- 5 files changed, 793 insertions(+), 58 deletions(-) create mode 100644 avahi-daemon/sd-daemon.c create mode 100644 avahi-daemon/sd-daemon.h diff --git a/avahi-daemon/Makefile.am b/avahi-daemon/Makefile.am index 0aac0fc..c406a62 100644 --- a/avahi-daemon/Makefile.am +++ b/avahi-daemon/Makefile.am @@ -1,7 +1,7 @@ # $Id$ # # This file is part of avahi. -# +# # avahi is free software; you can redistribute it and/or modify it # under the terms of the GNU Lesser General Public License as # published by the Free Software Foundation; either version 2 of the @@ -53,6 +53,7 @@ avahi_daemon_SOURCES = \ static-hosts.c static-hosts.h \ ini-file-parser.c ini-file-parser.h \ setproctitle.c setproctitle.h \ + sd-daemon.h sd-daemon.c \ ../avahi-client/check-nss.c avahi_daemon_CFLAGS = $(AM_CFLAGS) $(LIBDAEMON_CFLAGS) $(XML_CFLAGS) @@ -63,7 +64,7 @@ ini_file_parser_test_SOURCES = \ ini-file-parser-test.c ini_file_parser_test_CFLAGS = $(AM_CFLAGS) -ini_file_parser_test_LDADD = $(AM_LDADD) ../avahi-common/libavahi-common.la ../avahi-core/libavahi-core.la +ini_file_parser_test_LDADD = $(AM_LDADD) ../avahi-common/libavahi-common.la ../avahi-core/libavahi-core.la pkgsysconf_DATA = \ avahi-daemon.conf \ @@ -163,3 +164,7 @@ xmllint: install-data-local: test -z "$(localstatedir)/run" || $(mkdir_p) "$(DESTDIR)$(localstatedir)/run" + +update-systemd: + curl http://cgit.freedesktop.org/systemd/plain/src/sd-daemon.c > sd-daemon.c + curl http://cgit.freedesktop.org/systemd/plain/src/sd-daemon.h > sd-daemon.h diff --git a/avahi-daemon/main.c b/avahi-daemon/main.c index c3cbb0e..a32c706 100644 --- a/avahi-daemon/main.c +++ b/avahi-daemon/main.c @@ -79,6 +79,7 @@ #include "static-services.h" #include "static-hosts.h" #include "ini-file-parser.h" +#include "sd-daemon.h" #ifdef HAVE_DBUS #include "dbus-protocol.h" @@ -1455,10 +1456,11 @@ int main(int argc, char *argv[]) { if (config.use_syslog || config.daemonize) daemon_log_use = DAEMON_LOG_SYSLOG; - if (daemon_close_all(-1) < 0) { - avahi_log_error("Failed to close remaining file descriptors: %s", strerror(errno)); - goto finish; - } + if (sd_listen_fds(0) <= 0) + if (daemon_close_all(-1) < 0) { + avahi_log_error("Failed to close remaining file descriptors: %s", strerror(errno)); + goto finish; + } if (make_runtime_dir() < 0) goto finish; diff --git a/avahi-daemon/sd-daemon.c b/avahi-daemon/sd-daemon.c new file mode 100644 index 0000000..cb568b5 --- /dev/null +++ b/avahi-daemon/sd-daemon.c @@ -0,0 +1,448 @@ +/*-*- Mode: C; c-basic-offset: 8 -*-*/ + +/*** + Copyright 2010 Lennart Poettering + + Permission is hereby granted, free of charge, to any person + obtaining a copy of this software and associated documentation files + (the "Software"), to deal in the Software without restriction, + including without limitation the rights to use, copy, modify, merge, + publish, distribute, sublicense, and/or sell copies of the Software, + and to permit persons to whom the Software is furnished to do so, + subject to the following conditions: + + The above copyright notice and this permission notice shall be + included in all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + SOFTWARE. +***/ + +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "sd-daemon.h" + +int sd_listen_fds(int unset_environment) { + +#if defined(DISABLE_SYSTEMD) || !defined(__linux__) + return 0; +#else + int r, fd; + const char *e; + char *p = NULL; + unsigned long l; + + if (!(e = getenv("LISTEN_PID"))) { + r = 0; + goto finish; + } + + errno = 0; + l = strtoul(e, &p, 10); + + if (errno != 0) { + r = -errno; + goto finish; + } + + if (!p || *p || l <= 0) { + r = -EINVAL; + goto finish; + } + + /* Is this for us? */ + if (getpid() != (pid_t) l) { + r = 0; + goto finish; + } + + if (!(e = getenv("LISTEN_FDS"))) { + r = 0; + goto finish; + } + + errno = 0; + l = strtoul(e, &p, 10); + + if (errno != 0) { + r = -errno; + goto finish; + } + + if (!p || *p) { + r = -EINVAL; + goto finish; + } + + for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + (int) l; fd ++) { + int flags; + + if ((flags = fcntl(fd, F_GETFD)) < 0) { + r = -errno; + goto finish; + } + + if (flags & FD_CLOEXEC) + continue; + + if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) < 0) { + r = -errno; + goto finish; + } + } + + r = (int) l; + +finish: + if (unset_environment) { + unsetenv("LISTEN_PID"); + unsetenv("LISTEN_FDS"); + } + + return r; +#endif +} + +int sd_is_fifo(int fd, const char *path) { + struct stat st_fd; + + if (fd < 0) + return -EINVAL; + + memset(&st_fd, 0, sizeof(st_fd)); + if (fstat(fd, &st_fd) < 0) + return -errno; + + if (!S_ISFIFO(st_fd.st_mode)) + return 0; + + if (path) { + struct stat st_path; + + memset(&st_path, 0, sizeof(st_path)); + if (fstat(fd, &st_path) < 0) { + + if (errno == ENOENT || errno == ENOTDIR) + return 0; + + return -errno; + } + + return + st_path.st_dev == st_fd.st_dev && + st_path.st_ino == st_fd.st_ino; + } + + return 1; +} + +static int sd_is_socket_internal(int fd, int type, int listening) { + struct stat st_fd; + + if (fd < 0 || type < 0) + return -EINVAL; + + if (fstat(fd, &st_fd) < 0) + return -errno; + + if (!S_ISSOCK(st_fd.st_mode)) + return 0; + + if (type != 0) { + int other_type = 0; + socklen_t l = sizeof(other_type); + + if (getsockopt(fd, SOL_SOCKET, SO_TYPE, &other_type, &l) < 0) + return -errno; + + if (l != sizeof(other_type)) + return -EINVAL; + + if (other_type != type) + return 0; + } + + if (listening >= 0) { + int accepting = 0; + socklen_t l = sizeof(accepting); + + if (getsockopt(fd, SOL_SOCKET, SO_ACCEPTCONN, &accepting, &l) < 0) + return -errno; + + if (l != sizeof(accepting)) + return -EINVAL; + + if (!accepting != !listening) + return 0; + } + + return 1; +} + +union sockaddr_union { + struct sockaddr sa; + struct sockaddr_in in4; + struct sockaddr_in6 in6; + struct sockaddr_un un; + struct sockaddr_storage storage; +}; + +int sd_is_socket(int fd, int family, int type, int listening) { + int r; + + if (family < 0) + return -EINVAL; + + if ((r = sd_is_socket_internal(fd, type, listening)) <= 0) + return r; + + if (family > 0) { + union sockaddr_union sockaddr; + socklen_t l; + + memset(&sockaddr, 0, sizeof(sockaddr)); + l = sizeof(sockaddr); + + if (getsockname(fd, &sockaddr.sa, &l) < 0) + return -errno; + + if (l < sizeof(sa_family_t)) + return -EINVAL; + + return sockaddr.sa.sa_family == family; + } + + return 1; +} + +int sd_is_socket_inet(int fd, int family, int type, int listening, uint16_t port) { + union sockaddr_union sockaddr; + socklen_t l; + int r; + + if (family != 0 && family != AF_INET && family != AF_INET6) + return -EINVAL; + + if ((r = sd_is_socket_internal(fd, type, listening)) <= 0) + return r; + + memset(&sockaddr, 0, sizeof(sockaddr)); + l = sizeof(sockaddr); + + if (getsockname(fd, &sockaddr.sa, &l) < 0) + return -errno; + + if (l < sizeof(sa_family_t)) + return -EINVAL; + + if (sockaddr.sa.sa_family != AF_INET && + sockaddr.sa.sa_family != AF_INET6) + return 0; + + if (family > 0) + if (sockaddr.sa.sa_family != family) + return 0; + + if (port > 0) { + if (sockaddr.sa.sa_family == AF_INET) { + if (l < sizeof(struct sockaddr_in)) + return -EINVAL; + + return htons(port) == sockaddr.in4.sin_port; + } else { + if (l < sizeof(struct sockaddr_in6)) + return -EINVAL; + + return htons(port) == sockaddr.in6.sin6_port; + } + } + + return 1; +} + +int sd_is_socket_unix(int fd, int type, int listening, const char *path, size_t length) { + union sockaddr_union sockaddr; + socklen_t l; + int r; + + if ((r = sd_is_socket_internal(fd, type, listening)) <= 0) + return r; + + memset(&sockaddr, 0, sizeof(sockaddr)); + l = sizeof(sockaddr); + + if (getsockname(fd, &sockaddr.sa, &l) < 0) + return -errno; + + if (l < sizeof(sa_family_t)) + return -EINVAL; + + if (sockaddr.sa.sa_family != AF_UNIX) + return 0; + + if (path) { + if (length <= 0) + length = strlen(path); + + if (length <= 0) + /* Unnamed socket */ + return l == sizeof(sa_family_t); + + if (path[0]) + /* Normal path socket */ + return + (l >= sizeof(sa_family_t) + length + 1) && + memcmp(path, sockaddr.un.sun_path, length+1) == 0; + else + /* Abstract namespace socket */ + return + (l == sizeof(sa_family_t) + length) && + memcmp(path, sockaddr.un.sun_path, length) == 0; + } + + return 1; +} + +int sd_notify(int unset_environment, const char *state) { +#if defined(DISABLE_SYSTEMD) || !defined(__linux__) + return 0; +#else + int fd = -1, r; + struct msghdr msghdr; + struct iovec iovec; + union sockaddr_union sockaddr; + struct ucred *ucred; + union { + struct cmsghdr cmsghdr; + uint8_t buf[CMSG_SPACE(sizeof(struct ucred))]; + } control; + const char *e; + + if (!state) { + r = -EINVAL; + goto finish; + } + + if (!(e = getenv("NOTIFY_SOCKET"))) + return 0; + + /* Must be an abstract socket, or an absolute path */ + if ((e[0] != '@' && e[0] != '/') || e[1] == 0) { + r = -EINVAL; + goto finish; + } + + if ((fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) { + r = -errno; + goto finish; + } + + memset(&sockaddr, 0, sizeof(sockaddr)); + sockaddr.sa.sa_family = AF_UNIX; + strncpy(sockaddr.un.sun_path, e, sizeof(sockaddr.un.sun_path)); + + if (sockaddr.un.sun_path[0] == '@') + sockaddr.un.sun_path[0] = 0; + + memset(&iovec, 0, sizeof(iovec)); + iovec.iov_base = (char*) state; + iovec.iov_len = strlen(state); + + memset(&control, 0, sizeof(control)); + control.cmsghdr.cmsg_level = SOL_SOCKET; + control.cmsghdr.cmsg_type = SCM_CREDENTIALS; + control.cmsghdr.cmsg_len = CMSG_LEN(sizeof(struct ucred)); + + ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr); + ucred->pid = getpid(); + ucred->uid = getuid(); + ucred->gid = getgid(); + + memset(&msghdr, 0, sizeof(msghdr)); + msghdr.msg_name = &sockaddr; + msghdr.msg_namelen = sizeof(struct sockaddr_un); + msghdr.msg_iov = &iovec; + msghdr.msg_iovlen = 1; + msghdr.msg_control = &control; + msghdr.msg_controllen = control.cmsghdr.cmsg_len; + + if (sendmsg(fd, &msghdr, MSG_NOSIGNAL) < 0) { + r = -errno; + goto finish; + } + + r = 1; + +finish: + if (unset_environment) + unsetenv("NOTIFY_SOCKET"); + + if (fd >= 0) + close(fd); + + return r; +#endif +} + +int sd_notifyf(int unset_environment, const char *format, ...) { +#if defined(DISABLE_SYSTEMD) || !defined(__linux__) + return 0; +#else + va_list ap; + char *p = NULL; + int r; + + va_start(ap, format); + r = vasprintf(&p, format, ap); + va_end(ap); + + if (r < 0 || !p) + return -ENOMEM; + + r = sd_notify(unset_environment, p); + free(p); + + return r; +#endif +} + +int sd_booted(void) { +#if defined(DISABLE_SYSTEMD) || !defined(__linux__) + return 0; +#else + + struct stat a, b; + + /* We simply test whether the systemd cgroup hierarchy is + * mounted */ + + if (lstat("/cgroup", &a) < 0) + return 0; + + if (lstat("/cgroup/systemd", &b) < 0) + return 0; + + return a.st_dev != b.st_dev; +#endif +} diff --git a/avahi-daemon/sd-daemon.h b/avahi-daemon/sd-daemon.h new file mode 100644 index 0000000..fd6221f --- /dev/null +++ b/avahi-daemon/sd-daemon.h @@ -0,0 +1,257 @@ +/*-*- Mode: C; c-basic-offset: 8 -*-*/ + +#ifndef foosddaemonhfoo +#define foosddaemonhfoo + +/*** + Copyright 2010 Lennart Poettering + + Permission is hereby granted, free of charge, to any person + obtaining a copy of this software and associated documentation files + (the "Software"), to deal in the Software without restriction, + including without limitation the rights to use, copy, modify, merge, + publish, distribute, sublicense, and/or sell copies of the Software, + and to permit persons to whom the Software is furnished to do so, + subject to the following conditions: + + The above copyright notice and this permission notice shall be + included in all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + SOFTWARE. +***/ + +#include +#include + +#ifdef __cplusplus +extern "C" { +#endif + +/* + Reference implementation of a few systemd related interfaces for + writing daemons. These interfaces are trivial to implement. To + simplify porting we provide this reference implementation. + Applications are welcome to reimplement the algorithms described + here if they do not want to include these two source files. + + The following functionality is provided: + + - Support for logging with log levels on stderr + - File descriptor passing for socket-based activation + - Daemon startup and status notification + - Detection of systemd boots + + You may compile this with -DDISABLE_SYSTEMD to disable systemd + support. This makes all those calls NOPs that are directly related to + systemd (i.e. only sd_is_xxx() will stay useful). + + Since this is drop-in code we don't want any of our symbols to be + exported in any case. Hence we declare hidden visibility for all of + them. + + You may find an up-to-date version of these source files online: + + http://cgit.freedesktop.org/systemd/plain/src/sd-daemon.h + http://cgit.freedesktop.org/systemd/plain/src/sd-daemon.c + + This should compile on non-Linux systems, too, but with the + exception of the sd_is_xxx() calls all functions will become NOPs. + + See sd-daemon(7) for more information. +*/ + +#if __GNUC__ >= 4 +#define _sd_printf_attr_(a,b) __attribute__ ((format (printf, a, b))) +#define _sd_hidden_ __attribute__ ((visibility("hidden"))) +#else +#define _sd_printf_attr_(a,b) +#define _sd_hidden_ +#endif + +/* + Log levels for usage on stderr: + + fprintf(stderr, SD_NOTICE "Hello World!\n"); + + This is similar to printk() usage in the kernel. +*/ +#define SD_EMERG "<0>" /* system is unusable */ +#define SD_ALERT "<1>" /* action must be taken immediately */ +#define SD_CRIT "<2>" /* critical conditions */ +#define SD_ERR "<3>" /* error conditions */ +#define SD_WARNING "<4>" /* warning conditions */ +#define SD_NOTICE "<5>" /* normal but significant condition */ +#define SD_INFO "<6>" /* informational */ +#define SD_DEBUG "<7>" /* debug-level messages */ + +/* The first passed file descriptor is fd 3 */ +#define SD_LISTEN_FDS_START 3 + +/* + Returns how many file descriptors have been passed, or a negative + errno code on failure. Optionally, removes the $LISTEN_FDS and + $LISTEN_PID file descriptors from the environment (recommended, but + problematic in threaded environments). If r is the return value of + this function you'll find the file descriptors passed as fds + SD_LISTEN_FDS_START to SD_LISTEN_FDS_START+r-1. Returns a negative + errno style error code on failure. This function call ensures that + the FD_CLOEXEC flag is set for the passed file descriptors, to make + sure they are not passed on to child processes. If FD_CLOEXEC shall + not be set, the caller needs to unset it after this call for all file + descriptors that are used. + + See sd_listen_fds(3) for more information. +*/ +int sd_listen_fds(int unset_environment) _sd_hidden_; + +/* + Helper call for identifying a passed file descriptor. Returns 1 if + the file descriptor is a FIFO in the file system stored under the + specified path, 0 otherwise. If path is NULL a path name check will + not be done and the call only verifies if the file descriptor + refers to a FIFO. Returns a negative errno style error code on + failure. + + See sd_is_fifo(3) for more information. +*/ +int sd_is_fifo(int fd, const char *path) _sd_hidden_; + +/* + Helper call for identifying a passed file descriptor. Returns 1 if + the file descriptor is a socket of the specified family (AF_INET, + ...) and type (SOCK_DGRAM, SOCK_STREAM, ...), 0 otherwise. If + family is 0 a socket family check will not be done. If type is 0 a + socket type check will not be done and the call only verifies if + the file descriptor refers to a socket. If listening is > 0 it is + verified that the socket is in listening mode. (i.e. listen() has + been called) If listening is == 0 it is verified that the socket is + not in listening mode. If listening is < 0 no listening mode check + is done. Returns a negative errno style error code on failure. + + See sd_is_socket(3) for more information. +*/ +int sd_is_socket(int fd, int family, int type, int listening) _sd_hidden_; + +/* + Helper call for identifying a passed file descriptor. Returns 1 if + the file descriptor is an Internet socket, of the specified family + (either AF_INET or AF_INET6) and the specified type (SOCK_DGRAM, + SOCK_STREAM, ...), 0 otherwise. If version is 0 a protocol version + check is not done. If type is 0 a socket type check will not be + done. If port is 0 a socket port check will not be done. The + listening flag is used the same way as in sd_is_socket(). Returns a + negative errno style error code on failure. + + See sd_is_socket_inet(3) for more information. +*/ +int sd_is_socket_inet(int fd, int family, int type, int listening, uint16_t port) _sd_hidden_; + +/* + Helper call for identifying a passed file descriptor. Returns 1 if + the file descriptor is an AF_UNIX socket of the specified type + (SOCK_DGRAM, SOCK_STREAM, ...) and path, 0 otherwise. If type is 0 + a socket type check will not be done. If path is NULL a socket path + check will not be done. For normal AF_UNIX sockets set length to + 0. For abstract namespace sockets set length to the length of the + socket name (including the initial 0 byte), and pass the full + socket path in path (including the initial 0 byte). The listening + flag is used the same way as in sd_is_socket(). Returns a negative + errno style error code on failure. + + See sd_is_socket_unix(3) for more information. +*/ +int sd_is_socket_unix(int fd, int type, int listening, const char *path, size_t length) _sd_hidden_; + +/* + Informs systemd about changed daemon state. This takes a number of + newline seperated environment-style variable assignments in a + string. The following variables are known: + + READY=1 Tells systemd that daemon startup is finished (only + relevant for services of Type=notify). The passed + argument is a boolean "1" or "0". Since there is + little value in signalling non-readiness the only + value daemons should send is "READY=1". + + STATUS=... Passes a single-line status string back to systemd + that describes the daemon state. This is free-from + and can be used for various purposes: general state + feedback, fsck-like programs could pass completion + percentages and failing programs could pass a human + readable error message. Example: "STATUS=Completed + 66% of file system check..." + + ERRNO=... If a daemon fails, the errno-style error code, + formatted as string. Example: "ERRNO=2" for ENOENT. + + BUSERROR=... If a daemon fails, the D-Bus error-style error + code. Example: "BUSERROR=org.freedesktop.DBus.Error.TimedOut" + + MAINPID=... The main pid of a daemon, in case systemd did not + fork off the process itself. Example: "MAINPID=4711" + + Daemons can choose to send additional variables. However, it is + recommened to prefix variable names not listed above with X_. + + Returns a negative errno-style error code on failure. Returns > 0 + if systemd could be notified, 0 if it couldn't possibly because + systemd is not running. + + Example: When a daemon finished starting up, it could issue this + call to notify systemd about it: + + sd_notify(0, "READY=1"); + + See sd_notifyf() for more complete examples. + + See sd_notify(3) for more information. +*/ +int sd_notify(int unset_environment, const char *state) _sd_hidden_; + +/* + Similar to sd_notify() but takes a format string. + + Example 1: A daemon could send the following after initialization: + + sd_notifyf(0, "READY=1\n" + "STATUS=Processing requests...\n" + "MAINPID=%lu", + (unsigned long) getpid()); + + Example 2: A daemon could send the following shortly before + exiting, on failure: + + sd_notifyf(0, "STATUS=Failed to start up: %s\n" + "ERRNO=%i", + strerror(errno), + errno); + + See sd_notifyf(3) for more information. +*/ +int sd_notifyf(int unset_environment, const char *format, ...) _sd_printf_attr_(2,3) _sd_hidden_; + +/* + Returns > 0 if the system was booted with systemd. Returns < 0 on + error. Returns 0 if the system was not booted with systemd. Note + that all of the functions above handle non-systemd boots just + fine. You should NOT protect them with a call to this function. Also + note that this function checks whether the system, not the user + session is controlled by systemd. However the functions above work + for both session and system services. + + See sd_booted(3) for more information. +*/ +int sd_booted(void) _sd_hidden_; + +#ifdef __cplusplus +} +#endif + +#endif diff --git a/avahi-daemon/simple-protocol.c b/avahi-daemon/simple-protocol.c index 33e5db3..ffe079f 100644 --- a/avahi-daemon/simple-protocol.c +++ b/avahi-daemon/simple-protocol.c @@ -2,17 +2,17 @@ /*** This file is part of avahi. - + avahi is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. - + avahi 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 Lesser General Public License for more details. - + You should have received a copy of the GNU Lesser General Public License along with avahi; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 @@ -44,6 +44,7 @@ #include "simple-protocol.h" #include "main.h" +#include "sd-daemon.h" #ifdef ENABLE_CHROOT #include "chroot.h" @@ -75,7 +76,7 @@ struct Client { Server *server; ClientState state; - + int fd; AvahiWatch *watch; @@ -87,7 +88,7 @@ struct Client { AvahiSDNSServerBrowser *dns_server_browser; AvahiProtocol afquery; - + AVAHI_LLIST_FIELDS(Client, clients); }; @@ -98,7 +99,7 @@ struct Server { AVAHI_LLIST_HEAD(Client, clients); unsigned n_clients; - int bind_successful; + int remove_socket; }; static Server *server = NULL; @@ -122,7 +123,7 @@ static void client_free(Client *c) { c->server->poll_api->watch_free(c->watch); close(c->fd); - + AVAHI_LLIST_REMOVE(Client, clients, c->server->clients, c); avahi_free(c); } @@ -151,7 +152,7 @@ static void client_new(Server *s, int fd) { static void client_output(Client *c, const uint8_t*data, size_t size) { size_t k, m; - + assert(c); assert(data); @@ -170,7 +171,7 @@ static void client_output(Client *c, const uint8_t*data, size_t size) { static void client_output_printf(Client *c, const char *format, ...) { char *t; va_list ap; - + va_start(ap, format); t = avahi_strdup_vprintf(format, ap); va_end(ap); @@ -186,11 +187,11 @@ static void host_name_resolver_callback( AvahiResolverEvent event, const char *hostname, const AvahiAddress *a, - AVAHI_GCC_UNUSED AvahiLookupResultFlags flags, + AVAHI_GCC_UNUSED AvahiLookupResultFlags flags, void* userdata) { Client *c = userdata; - + assert(c); if (event == AVAHI_RESOLVER_FAILURE) @@ -213,9 +214,9 @@ static void address_resolver_callback( const char *hostname, AVAHI_GCC_UNUSED AvahiLookupResultFlags flags, void* userdata) { - + Client *c = userdata; - + assert(c); if (event == AVAHI_RESOLVER_FAILURE) @@ -236,10 +237,10 @@ static void dns_server_browser_callback( uint16_t port, AVAHI_GCC_UNUSED AvahiLookupResultFlags flags, void* userdata) { - + Client *c = userdata; char t[AVAHI_ADDRESS_STR_MAX]; - + assert(c); if (!a) @@ -257,7 +258,7 @@ static void dns_server_browser_callback( case AVAHI_BROWSER_NEW: case AVAHI_BROWSER_REMOVE: - + avahi_address_snprint(t, sizeof(t), a); client_output_printf(c, "%c %i %u %s %u\n", event == AVAHI_BROWSER_NEW ? '>' : '<', interface, protocol, t, port); break; @@ -314,7 +315,7 @@ static void handle_line(Client *c, const char *s) { avahi_log_debug(__FILE__": Got %s request for '%s'.", cmd, arg); } else if (strcmp(cmd, "RESOLVE-ADDRESS") == 0 && n_args == 2) { AvahiAddress addr; - + if (!(avahi_address_parse(arg, AVAHI_PROTO_UNSPEC, &addr))) { client_output_printf(c, "%+i Failed to parse address \"%s\".\n", AVAHI_ERR_INVALID_ADDRESS, arg); c->state = CLIENT_DEAD; @@ -376,7 +377,7 @@ static void handle_input(Client *c) { k = e - (char*) c->inbuf; *e = 0; - + handle_line(c, c->inbuf); c->inbuf_length -= k + 1; memmove(c->inbuf, e+1, c->inbuf_length); @@ -390,7 +391,7 @@ static void client_work(AvahiWatch *watch, AVAHI_GCC_UNUSED int fd, AvahiWatchEv if ((events & AVAHI_WATCH_IN) && c->inbuf_length < sizeof(c->inbuf)) { ssize_t r; - + if ((r = read(c->fd, c->inbuf + c->inbuf_length, sizeof(c->inbuf) - c->inbuf_length)) <= 0) { if (r < 0) avahi_log_warn("read(): %s", strerror(errno)); @@ -415,7 +416,7 @@ static void client_work(AvahiWatch *watch, AVAHI_GCC_UNUSED int fd, AvahiWatchEv assert((size_t) r <= c->outbuf_length); c->outbuf_length -= r; - + if (c->outbuf_length) memmove(c->outbuf, c->outbuf + r, c->outbuf_length - r); @@ -426,7 +427,7 @@ static void client_work(AvahiWatch *watch, AVAHI_GCC_UNUSED int fd, AvahiWatchEv } c->server->poll_api->watch_update( - watch, + watch, (c->outbuf_length > 0 ? AVAHI_WATCH_OUT : 0) | (c->inbuf_length < sizeof(c->inbuf) ? AVAHI_WATCH_IN : 0)); } @@ -445,59 +446,83 @@ static void server_work(AVAHI_GCC_UNUSED AvahiWatch *watch, int fd, AvahiWatchEv client_new(s, cfd); } } - + int simple_protocol_setup(const AvahiPoll *poll_api) { struct sockaddr_un sa; mode_t u; + int n; assert(!server); server = avahi_new(Server, 1); server->poll_api = poll_api; - server->bind_successful = 0; + server->remove_socket = 0; server->fd = -1; server->n_clients = 0; AVAHI_LLIST_HEAD_INIT(Client, server->clients); server->watch = NULL; - + u = umask(0000); - if ((server->fd = socket(PF_LOCAL, SOCK_STREAM, 0)) < 0) { - avahi_log_warn("socket(PF_LOCAL, SOCK_STREAM, 0): %s", strerror(errno)); + if ((n = sd_listen_fds(1)) < 0) { + avahi_log_warn("Failed to acquire systemd file descriptors: %s", strerror(-n)); goto fail; } - memset(&sa, 0, sizeof(sa)); - sa.sun_family = AF_LOCAL; - strncpy(sa.sun_path, AVAHI_SOCKET, sizeof(sa.sun_path)-1); - - /* We simply remove existing UNIX sockets under this name. The - Avahi daemon makes sure that it runs only once on a host, - therefore sockets that already exist are stale and may be - removed without any ill effects */ - - unlink(AVAHI_SOCKET); - - if (bind(server->fd, (struct sockaddr*) &sa, sizeof(sa)) < 0) { - avahi_log_warn("bind(): %s", strerror(errno)); + if (n > 1) { + avahi_log_warn("Too many systemd file descriptors passed."); goto fail; } - server->bind_successful = 1; - - if (listen(server->fd, 2) < 0) { - avahi_log_warn("listen(): %s", strerror(errno)); - goto fail; + if (n == 1) { + int r; + + if ((r = sd_is_socket(AF_LOCAL, SOCK_STREAM, 1, 0)) < 0) { + avahi_log_warn("Passed systemd file descriptor is of wrong type: %s", strerror(-r)); + goto fail; + } + + server->fd = SD_LISTEN_FDS_START; + + } else { + + if ((server->fd = socket(AF_LOCAL, SOCK_STREAM, 0)) < 0) { + avahi_log_warn("socket(AF_LOCAL, SOCK_STREAM, 0): %s", strerror(errno)); + goto fail; + } + + memset(&sa, 0, sizeof(sa)); + sa.sun_family = AF_LOCAL; + strncpy(sa.sun_path, AVAHI_SOCKET, sizeof(sa.sun_path)-1); + + /* We simply remove existing UNIX sockets under this name. The + Avahi daemon makes sure that it runs only once on a host, + therefore sockets that already exist are stale and may be + removed without any ill effects */ + + unlink(AVAHI_SOCKET); + + if (bind(server->fd, (struct sockaddr*) &sa, sizeof(sa)) < 0) { + avahi_log_warn("bind(): %s", strerror(errno)); + goto fail; + } + + server->remove_socket = 1; + + if (listen(server->fd, SOMAXCONN) < 0) { + avahi_log_warn("listen(): %s", strerror(errno)); + goto fail; + } } umask(u); server->watch = poll_api->watch_new(poll_api, server->fd, AVAHI_WATCH_IN, server_work, server); - + return 0; fail: - + umask(u); simple_protocol_shutdown(); @@ -508,7 +533,7 @@ void simple_protocol_shutdown(void) { if (server) { - if (server->bind_successful) + if (server->remove_socket) #ifdef ENABLE_CHROOT avahi_chroot_helper_unlink(AVAHI_SOCKET); #else @@ -520,12 +545,12 @@ void simple_protocol_shutdown(void) { if (server->watch) server->poll_api->watch_free(server->watch); - + if (server->fd >= 0) close(server->fd); avahi_free(server); - + server = NULL; } } @@ -534,7 +559,7 @@ void simple_protocol_restart_queries(void) { Client *c; /* Restart queries in case of local domain name changes */ - + assert(server); for (c = server->clients; c; c = c->clients_next) @@ -543,5 +568,3 @@ void simple_protocol_restart_queries(void) { c->dns_server_browser = avahi_s_dns_server_browser_new(avahi_server, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, NULL, AVAHI_DNS_SERVER_RESOLVE, c->afquery, AVAHI_LOOKUP_USE_MULTICAST, dns_server_browser_callback, c); } } - - -- 2.39.5