From: Kay Sievers Date: Thu, 7 Oct 2010 12:59:11 +0000 (+0200) Subject: udevd: add sd-daemon.c X-Git-Tag: 174~325 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=392ef7a28a7003a11f5e1e56617551ff5b9eabf9;p=systemd udevd: add sd-daemon.c --- diff --git a/Makefile.am b/Makefile.am index 39971be0..3d9773b6 100644 --- a/Makefile.am +++ b/Makefile.am @@ -150,7 +150,9 @@ udev_common_sources =\ udev_udevd_SOURCES = \ $(udev_common_sources) \ - udev/udevd.c + udev/udevd.c \ + udev/sd-daemon.h \ + udev/sd-daemon.c udev_udevd_LDADD = libudev/libudev-private.la udev_udevadm_SOURCES = \ diff --git a/udev/sd-daemon.c b/udev/sd-daemon.c new file mode 100644 index 00000000..e12fb048 --- /dev/null +++ b/udev/sd-daemon.c @@ -0,0 +1,436 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + 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 + +#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 (stat(path, &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 < offsetof(struct sockaddr_un, sun_path)) + 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 < offsetof(struct sockaddr_un, sun_path)) + 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 < offsetof(struct sockaddr_un, sun_path)) + 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 == offsetof(struct sockaddr_un, sun_path); + + if (path[0]) + /* Normal path socket */ + return + (l >= offsetof(struct sockaddr_un, sun_path) + length + 1) && + memcmp(path, sockaddr.un.sun_path, length+1) == 0; + else + /* Abstract namespace socket */ + return + (l == offsetof(struct sockaddr_un, sun_path) + 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__) || !defined(SOCK_CLOEXEC) + return 0; +#else + int fd = -1, r; + struct msghdr msghdr; + struct iovec iovec; + union sockaddr_union sockaddr; + 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(&msghdr, 0, sizeof(msghdr)); + msghdr.msg_name = &sockaddr; + msghdr.msg_namelen = offsetof(struct sockaddr_un, sun_path) + strlen(e); + + if (msghdr.msg_namelen > sizeof(struct sockaddr_un)) + msghdr.msg_namelen = sizeof(struct sockaddr_un); + + msghdr.msg_iov = &iovec; + msghdr.msg_iovlen = 1; + + 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("/sys/fs/cgroup", &a) < 0) + return 0; + + if (lstat("/sys/fs/cgroup/systemd", &b) < 0) + return 0; + + return a.st_dev != b.st_dev; +#endif +} diff --git a/udev/sd-daemon.h b/udev/sd-daemon.h new file mode 100644 index 00000000..fdf3cc03 --- /dev/null +++ b/udev/sd-daemon.h @@ -0,0 +1,265 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +#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. +*/ + +#ifndef _sd_printf_attr_ +#if __GNUC__ >= 4 +#define _sd_printf_attr_(a,b) __attribute__ ((format (printf, a, b))) +#else +#define _sd_printf_attr_(a,b) +#endif +#endif + +#ifndef _sd_hidden_ +#if (__GNUC__ >= 4) && !defined(SD_EXPORT_SYMBOLS) +#define _sd_hidden_ __attribute__ ((visibility("hidden"))) +#else +#define _sd_hidden_ +#endif +#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 separated 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/udev/udevd.c b/udev/udevd.c index 0ec3c3d4..2efab5b3 100644 --- a/udev/udevd.c +++ b/udev/udevd.c @@ -45,6 +45,7 @@ #include #include "udev.h" +#include "sd-daemon.h" #define UDEVD_PRIORITY -4 #define UDEV_PRIORITY -2 @@ -959,66 +960,6 @@ static int mem_size_mb(void) return memsize; } -static int init_notify(const char *state) -{ - int fd = -1, r; - struct msghdr msghdr; - struct iovec iovec; - union { - struct sockaddr sa; - struct sockaddr_un un; - } sockaddr; - const char *e; - - if (!(e = getenv("NOTIFY_SOCKET"))) { - r = 0; - goto finish; - } - - /* 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(&msghdr, 0, sizeof(msghdr)); - msghdr.msg_name = &sockaddr; - msghdr.msg_namelen = sizeof(sa_family_t) + strlen(e); - if (msghdr.msg_namelen > sizeof(struct sockaddr_un)) - msghdr.msg_namelen = sizeof(struct sockaddr_un); - msghdr.msg_iov = &iovec; - msghdr.msg_iovlen = 1; - - if (sendmsg(fd, &msghdr, MSG_NOSIGNAL) < 0) { - r = -errno; - goto finish; - } - - r = 0; - -finish: - if (fd >= 0) - close(fd); - - return r; -} - int main(int argc, char *argv[]) { struct udev *udev; @@ -1271,7 +1212,7 @@ int main(int argc, char *argv[]) goto exit; } } else { - init_notify("READY=1"); + sd_notify(1, "READY=1"); } /* set scheduling priority for the main daemon process */