From 238909aaff10489fe538c8c54e3f82fe8a54b849 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Wed, 2 Jun 2010 04:37:40 +0200 Subject: systemd: add support for acquiring socket from systemd --- avahi-daemon/sd-daemon.c | 448 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 448 insertions(+) create mode 100644 avahi-daemon/sd-daemon.c (limited to 'avahi-daemon/sd-daemon.c') 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 +} -- cgit