diff options
| -rw-r--r-- | src/client.c | 9 | ||||
| -rw-r--r-- | src/daemonise.c | 37 | ||||
| -rw-r--r-- | src/daemonise.h | 20 | ||||
| -rw-r--r-- | src/satd.c | 125 |
4 files changed, 113 insertions, 78 deletions
diff --git a/src/client.c b/src/client.c index 1bf8440..a0f58e3 100644 --- a/src/client.c +++ b/src/client.c @@ -63,17 +63,17 @@ send_command(enum command cmd, size_t n, const char *restrict msg) /* Get socket address. */ dir = getenv("XDG_RUNTIME_DIR"), dir = (dir ? dir : "/run"); - if (strlen(dir) + sizeof("/satd.socket") > sizeof(address.sun_path)) + if (strlen(dir) + sizeof("/" PACKAGE "/socket") > sizeof(address.sun_path)) t ((errno = ENAMETOOLONG)); - stpcpy(stpcpy(address.sun_path, dir), "/satd.socket"); + stpcpy(stpcpy(address.sun_path, dir), "/" PACKAGE "/state"); /* Yes, "state", It is temporary. */ address.sun_family = AF_UNIX; /* Any daemon listening? */ fd = open(address.sun_path, O_RDONLY); if (fd == -1) { - t (errno != ENOENT); + t ((errno != ENOENT) && (errno != ENOTDIR)); } else { - if (flock(fd, LOCK_SH | LOCK_NB) == -1) + if (flock(fd, LOCK_EX | LOCK_NB /* and LOCK_DRY if that was ever added... */)) t (start = 0, errno != EWOULDBLOCK); else flock(fd, LOCK_UN); @@ -97,6 +97,7 @@ send_command(enum command cmd, size_t n, const char *restrict msg) } /* Create socket. */ + stpcpy(strrchr(address.sun_path, '/'), "/socket"); t ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1); t (connect(fd, (const struct sockaddr *)(_cvoid = &address), (socklen_t)sizeof(address)) == -1); diff --git a/src/daemonise.c b/src/daemonise.c index c9de08a..f8da122 100644 --- a/src/daemonise.c +++ b/src/daemonise.c @@ -60,7 +60,7 @@ static char* __pidfile = NULL; */ static int dup_at_least_3(int old) { - int intermediary[] = { -1, -1, -1 }; + int intermediary[3]; int i = 0, saved_errno; do @@ -73,12 +73,12 @@ static int dup_at_least_3(int old) intermediary[i++] = old; } while (old < 3); + i--; fail: saved_errno = errno; - if (intermediary[0] >= 0) close(intermediary[0]); - if (intermediary[1] >= 0) close(intermediary[1]); - if (intermediary[2] >= 0) close(intermediary[2]); + while (i--) + close(intermediary[i]); errno = saved_errno; return old; } @@ -167,6 +167,7 @@ static int dup_at_least_3(int old) * - `DAEMONISE_KEEP_STDIN` * - `DAEMONISE_KEEP_STDOUT` * - `DAEMONISE_KEEP_FDS` + * - `DAEMONISE_NEW_PID` * @param ... Enabled if `DAEMONISE_KEEP_FDS` is used, * do not add anything if `DAEMONISE_KEEP_FDS` * is unused. This is a `-1`-terminated list @@ -182,9 +183,10 @@ static int dup_at_least_3(int old) * has exited without removing the PID file. * @throws EINVAL `flags` contains an unsupported bit, both * `DAEMONISE_KEEP_STDERR` and `DAEMONISE_CLOSE_STDERR` - * are set, or both `DAEMONISE_CLOSE_STDERR` and - * `DAEMONISE_KEEP_FDS` are set whilst `2` is - * in the list of file descriptor not to close, + * are set, both `DAEMONISE_NO_PID_FILE` and + * `DAEMONISE_NEW_PID`, or both `DAEMONISE_CLOSE_STDERR` + * and `DAEMONISE_KEEP_FDS` are set whilst `2` is + * in the list of file descriptor not to close. * @throws Any error specified for signal(3). * @throws Any error specified for sigemptyset(3). * @throws Any error specified for sigprocmask(3). @@ -218,20 +220,22 @@ int daemonise(const char* name, int flags, ...) /* Validate flags. */ - if (flags & ~2047) + if (flags & (int)~(2048L * 2 - 1)) return errno = EINVAL, -1; - if (flags & DAEMONISE_KEEP_STDERR) - if (flags & DAEMONISE_CLOSE_STDERR) + if ((flags & DAEMONISE_KEEP_STDERR) && (flags & DAEMONISE_CLOSE_STDERR)) + return errno = EINVAL, -1; + if ((flags & DAEMONISE_NO_PID_FILE) && (flags & DAEMONISE_NEW_PID)) return errno = EINVAL, -1; /* Find out which file descriptors not too close. */ - if ((flags & DAEMONISE_KEEP_FDS) == 0) + if (flags & DAEMONISE_KEEP_FDS) { va_start(args, flags); - while (va_arg(args, int) >= 0) + while ((fd = va_arg(args, int)) >= 0) if ((fd > 2) && (keepmax < fd)) keepmax = fd; + fd = -1; va_end(args); keep = calloc((size_t)keepmax + 1, sizeof(char)); t (keep == NULL); @@ -249,8 +253,8 @@ int daemonise(const char* name, int flags, ...) keep[fd] = 1; break; } - va_end(args); fd = -1; + va_end(args); } /* We assume that the maximum file descriptor is not extremely large. * We also assume the number of file descriptors too keep is very small, @@ -264,7 +268,7 @@ int daemonise(const char* name, int flags, ...) for (i = 3; (rlim_t)i < rlimit.rlim_cur; i++) /* File descriptors with numbers above and including * `rlimit.rlim_cur` cannot be created. They cause EBADF. */ - if ((keep == NULL) || (keep[i] == 0)) + if ((i > keepmax) || (keep[i] == 0)) close(i); } free(keep), keep = NULL; @@ -272,7 +276,8 @@ int daemonise(const char* name, int flags, ...) /* Reset all signal handlers. */ if ((flags & DAEMONISE_NO_SIG_DFL) == 0) for (i = 1; i < _NSIG; i++) - t (signal(i, SIG_DFL) == SIG_ERR); + if (signal(i, SIG_DFL) == SIG_ERR) + t (errno != EINVAL); /* Set signal mask. */ if ((flags & DAEMONISE_KEEP_SIGMASK) == 0) @@ -337,7 +342,7 @@ int daemonise(const char* name, int flags, ...) t (__pidfile == NULL); stpcpy(stpcpy(stpcpy(__pidfile, "/run/"), name), ".pid"); } - fd = open(__pidfile, O_WRONLY | O_CREAT | O_EXCL, 0644); + fd = open(__pidfile, O_WRONLY | O_CREAT | ((flags & DAEMONISE_NEW_PID) ? 0 : O_EXCL), 0644); if (fd == -1) { saved_errno = errno; diff --git a/src/daemonise.h b/src/daemonise.h index c590174..6585154 100644 --- a/src/daemonise.h +++ b/src/daemonise.h @@ -50,6 +50,8 @@ /** * Do not create a PID file. + * + * Cannot be combined with `DAEMONISE_NEW_PID`. */ #define DAEMONISE_NO_PID_FILE 32 @@ -57,7 +59,7 @@ * Do not close stderr even if it is * a terminal device. * - * Cannot be combined with `DAEMONISE_KEEP_STDERR`. + * Cannot be combined with `DAEMONISE_CLOSE_STDERR`. */ #define DAEMONISE_KEEP_STDERR 64 @@ -85,6 +87,16 @@ */ #define DAEMONISE_KEEP_FDS 1024 +/** + * Override the PID file if it already exists, + * rather than failing. It is a bad idea to do + * this unless you already made sure that the + * daemon is not already running. + * + * Cannot be combined with `DAEMONISE_NO_PID_FILE`. + */ +#define DAEMONISE_NEW_PID 2048 + /** @@ -167,6 +179,7 @@ * - `DAEMONISE_KEEP_STDIN` * - `DAEMONISE_KEEP_STDOUT` * - `DAEMONISE_KEEP_FDS` + * - `DAEMONISE_NEW_PID` * @param ... Enabled if `DAEMONISE_KEEP_FDS` is used, * do not add anything if `DAEMONISE_KEEP_FDS` * is unused. This is a `-1`-terminated list @@ -182,8 +195,9 @@ * has exited without removing the PID file. * @throws EINVAL `flags` contains an unsupported bit, both * `DAEMONISE_KEEP_STDERR` and `DAEMONISE_CLOSE_STDERR` - * are set, or both `DAEMONISE_CLOSE_STDERR` and - * `DAEMONISE_KEEP_FDS` are set whilst `2` is + * are set, both `DAEMONISE_NO_PID_FILE` and + * `DAEMONISE_NEW_PID`, or both `DAEMONISE_CLOSE_STDERR` + * and `DAEMONISE_KEEP_FDS` are set whilst `2` is * in the list of file descriptor not to close. * @throws Any error specified for signal(3). * @throws Any error specified for sigemptyset(3). @@ -48,7 +48,7 @@ USAGE("[-f]") /** - * Create the socket. + * Create the socket, but not its directory. * * @param address Output parameter for the socket address. * @return The file descriptor for the socket, -1 on error. @@ -63,37 +63,19 @@ create_socket(struct sockaddr_un *address) /* Get socket address. */ dir = getenv("XDG_RUNTIME_DIR"), dir = (dir ? dir : "/run"); - if (strlen(dir) + sizeof("/satd.socket") > sizeof(address->sun_path)) + if (strlen(dir) + sizeof("/" PACKAGE "/socket") > sizeof(address->sun_path)) t ((errno = ENAMETOOLONG)); - stpcpy(stpcpy(address->sun_path, dir), "/satd.socket"); + stpcpy(stpcpy(address->sun_path, dir), "/" PACKAGE "/socket"); address->sun_family = AF_UNIX; - /* Check that no living process owns the socket. */ - fd = open(address->sun_path, O_RDONLY); - if (fd == -1) { - t (errno != ENOENT); - goto does_not_exist; - } else if (flock(fd, LOCK_EX | LOCK_NB) == -1) { - t (errno != EWOULDBLOCK); - fprintf(stderr, "%s: the daemon's socket file is already in use.\n", argv0); - errno = 0; - goto fail; - } - /* Create socket. */ unlink(address->sun_path); - flock(fd, LOCK_UN); - close(fd), fd = -1; -does_not_exist: t ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1); t (fchmod(fd, S_IRWXU) == -1); t (bind(fd, (const struct sockaddr *)(_cvoid = address), (socklen_t)sizeof(*address)) == -1); /* EADDRINUSE just means that the file already exists, not that it is actually used. */ bound = 1; - /* Mark the socket as owned by a living process. */ - t (flock(fd, LOCK_SH)); - return fd; fail: saved_errno = errno; @@ -107,6 +89,51 @@ fail: /** + * Create the state file, and its directory. + * + * This will also check that the daemon is not + * running. The daemon holds a shared lock on + * the state file. + * + * @return A file descriptor to the state file, -1 on error. + */ +static int +create_state(void) +{ + const char *dir; + char *path; + char *p; + int fd, saved_errno; + + /* Create directory. */ + dir = getenv("XDG_RUNTIME_DIR"), dir = (dir ? dir : "/run"); + t (!(path = malloc(strlen(dir) * sizeof(char) + sizeof("/" PACKAGE "/state")))); + p = stpcpy(stpcpy(path, dir), "/" PACKAGE); + t (mkdir(path, S_IRWXU) && (errno != EEXIST)); + + /* Open file. */ + stpcpy(p, "/state"); + t (fd = open(path, O_RDWR | O_CREAT /* but not O_EXCL */, S_IRUSR | S_IWUSR), fd == -1); + free(path), path = NULL; + + /* Check that the daemon is not running, and mark it as running. */ + if (flock(fd, LOCK_EX | LOCK_NB)) { + t (errno != EWOULDBLOCK); + fprintf(stderr, "%s: the daemon's state file is already in use.\n", argv0); + errno = 0; + goto fail; + } + + return fd; +fail: + saved_errno = errno; + free(path); + errno = saved_errno; + return -1; +} + + +/** * Construct the pathname for the hook script. * * @param env The environment variable to use for the beginning @@ -159,16 +186,16 @@ fail: static int dup2_and_null(int old, int new) { - int want, fd = -1; + int fd = -1; int saved_errno; if (old == new) goto done; t (dup2(old, new) == -1); - close(old), want = old; - if (want >= 3) goto done; + close(old); + if (old >= 3) goto done; t (fd = open("/dev/null", O_RDWR), fd == -1); - if (fd == want) goto done; - t (dup2(fd, want) == -1); + if (fd == old) goto done; + t (dup2(fd, old) == -1); close(fd), fd = -1; done: @@ -195,11 +222,17 @@ fail: int main(int argc, char *argv[]) { +#define GET_FD(FD, WANT, CALL) \ + t (FD = CALL, FD == -1); \ + t (dup2_and_null(FD, WANT) == -1); \ + FD = WANT +#define HOOKPATH(PRE, SUF) \ + t (path = path ? path : hookpath(PRE, SUF), !path && errno) + struct sockaddr_un address; int sock = -1, state = -1, boot = -1, real = -1, foreground = 0; char *path = NULL; struct itimerspec spec; - const char *dir; /* Parse command line. */ if (argc > 0) argv0 = argv[0]; @@ -210,38 +243,20 @@ main(int argc, char *argv[]) /* Get hook-script pathname. */ if (!getenv("SAT_HOOK_PATH")) { - t (path = hookpath("XDG_CONFIG_HOME", "/sat/hook"), !path && errno); - t (path = path ? path : hookpath("HOME", "/.config/sat/hook"), !path && errno); - t (path = path ? path : hookpath(NULL, "/.config/sat/hook"), !path && errno); + HOOKPATH("XDG_CONFIG_HOME", "/sat/hook"); + HOOKPATH("HOME", "/.config/sat/hook"); + HOOKPATH(NULL, "/.config/sat/hook"); t (setenv("SAT_HOOK_PATH", path ? path : "/etc/sat/hook", 1)); free(path), path = NULL; } - /* Open/create state file. */ - dir = getenv("XDG_RUNTIME_DIR"), dir = (dir ? dir : "/run"); - t (!(path = malloc(strlen(dir) * sizeof(char) + sizeof("/satd.state")))); - stpcpy(stpcpy(path, dir), "/satd.state"); - t (state = open(path, O_RDWR | O_CREAT /* but not O_EXCL */, S_IRWXU), state == -1); - free(path), path = NULL; - - /* The state file shall be on fd STATE_FILENO. */ - t (dup2_and_null(state, STATE_FILENO) == -1); - state = STATE_FILENO; - - /* Create socket. */ - t (sock = create_socket(&address), sock == -1); - t (dup2_and_null(sock, SOCK_FILENO) == -1); - sock = SOCK_FILENO; - - /* Create CLOCK_BOOTTIME timer. */ - t (boot = timerfd_create(CLOCK_BOOTTIME, 0), boot == -1); - t (dup2_and_null(boot, BOOT_FILENO) == -1); - boot = BOOT_FILENO; + /* Open/create state file, and create socket. */ + GET_FD(state, STATE_FILENO, create_state()); + GET_FD(sock, SOCK_FILENO, create_socket(&address)); - /* Create CLOCK_REALTIME timer. */ - t (real = timerfd_create(CLOCK_REALTIME, 0), real == -1); - t (dup2_and_null(real, BOOT_FILENO) == -1); - real = BOOT_FILENO; + /* Create timers. */ + GET_FD(boot, BOOT_FILENO, timerfd_create(CLOCK_BOOTTIME, 0)); + GET_FD(real, REAL_FILENO, timerfd_create(CLOCK_REALTIME, 0)); /* Configure timers. */ memset(&spec, 0, sizeof(spec)); @@ -256,7 +271,7 @@ main(int argc, char *argv[]) #endif /* Daemonise. */ - t (foreground ? 0 : daemonise("satd", DAEMONISE_KEEP_FDS, 3, 4, 5, 6, -1)); + t (foreground ? 0 : daemonise("satd", DAEMONISE_KEEP_FDS | DAEMONISE_NEW_PID, 3, 4, 5, 6, -1)); /* Change to a process image without all this initialisation text. */ execl(LIBEXECDIR "/" PACKAGE "/satd-diminished", argv0, address.sun_path, NULL); |