diff options
Diffstat (limited to 'src/coopgammad.c')
| -rw-r--r-- | src/coopgammad.c | 386 |
1 files changed, 196 insertions, 190 deletions
diff --git a/src/coopgammad.c b/src/coopgammad.c index dec35b0..a632e71 100644 --- a/src/coopgammad.c +++ b/src/coopgammad.c @@ -54,6 +54,12 @@ +/** + * Lists all function recognised adjustment methods, + * will call macro X with the code for the each + * adjustment method as the first argument and + * corresponding name as the second argument + */ #define LIST_ADJUSTMENT_METHODS \ X(LIBGAMMA_METHOD_DUMMY, "dummy") \ X(LIBGAMMA_METHOD_X_RANDR, "randr") \ @@ -64,27 +70,43 @@ -extern char* restrict pidpath; -extern char* restrict socketpath; -extern int gerror; +/** + * Used by initialisation functions as their return type. If a + * value not listed here is returned by such function, it is the + * exit value the process shall exit with as soon as possible. + */ +enum init_status +{ + /** + * Initialisation was successful + */ + INIT_SUCCESS = -1, + + /** + * Initialisation failed + */ + INIT_FAILURE = -2, + + /** + * Server is already running + */ + INIT_RUNNING = -3, +}; /** * The pathname of the PID file */ +extern char* restrict pidpath; char* restrict pidpath = NULL; /** * The pathname of the socket */ +extern char* restrict socketpath; char* restrict socketpath = NULL; -/** - * Error code returned by libgamma - */ -int gerror; /* do not marshal */ - /** @@ -165,13 +187,9 @@ static int get_method(const char* restrict arg) * Fork the process to the background * * @param keep_stderr Keep stderr open? - * @return 1: Success - * 2: Failure - * 4: The service is already running - * Otherwise: The negative of the exit value the - * process should have and shall exit immediately + * @return An `enum init_status` value or an exit value */ -static int daemonise(int keep_stderr) +static enum init_status daemonise(int keep_stderr) { pid_t pid; int fd = -1, saved_errno; @@ -188,70 +206,69 @@ static int daemonise(int keep_stderr) if ((notify_rw[1] = dup2atleast(notify_rw[1], STDERR_FILENO + 1)) < 0) goto fail; - switch ((pid = fork())) + if ((pid = fork()) < 0) + goto fail; + if (pid > 0) { - case -1: - goto fail; - case 0: - /* Child */ - close(notify_rw[0]), notify_rw[0] = -1; - if (setsid() < 0) - goto fail; - switch (fork()) - { - case -1: - goto fail; - case 0: - /* Replace std* with /dev/null */ - fd = open("/dev/null", O_RDWR); - if (fd < 0) - goto fail; -#define xdup2(s, d) do if (s != d) { close(d); if (dup2(s, d) < 0) goto fail; } while (0) - xdup2(fd, STDIN_FILENO); - xdup2(fd, STDOUT_FILENO); - if (keep_stderr) - xdup2(fd, STDERR_FILENO); - if (fd > STDERR_FILENO) - close(fd); - fd = -1; - - /* Update PID file */ - fd = open(pidpath, O_WRONLY); - if (fd < 0) - goto fail; - if (dprintf(fd, "%llu\n", (unsigned long long)getpid()) < 0) - goto fail; - close(fd), fd = -1; - - /* Notify */ - if (write(notify_rw[1], &a_byte, 1) <= 0) - goto fail; - close(notify_rw[1]); - break; - default: - /* Parent */ - return 0; - } - break; - default: - /* Parent */ + /* Original process (parent): */ waitpid(pid, NULL, 0); close(notify_rw[1]), notify_rw[1] = -1; got = read(notify_rw[0], &a_byte, 1); if (got < 0) goto fail; close(notify_rw[0]); - return -(got == 0); + errno = 0; + return got == 0 ? INIT_FAILURE : (enum init_status)0; } - return 1; + /* Intermediary process (child): */ + close(notify_rw[0]), notify_rw[0] = -1; + if (setsid() < 0) + goto fail; + if ((pid = fork()) < 0) + goto fail; + if (pid > 0) + { + /* Intermediary process (parent): */ + return (enum init_status)0; + } + + /* Daemon process (child): */ + + /* Replace std* with /dev/null */ + fd = open("/dev/null", O_RDWR); + if (fd < 0) + goto fail; +#define xdup2(s, d) do if (s != d) { close(d); if (dup2(s, d) < 0) goto fail; } while (0) + xdup2(fd, STDIN_FILENO); + xdup2(fd, STDOUT_FILENO); + if (keep_stderr) + xdup2(fd, STDERR_FILENO); + if (fd > STDERR_FILENO) + close(fd); + fd = -1; + + /* Update PID file */ + fd = open(pidpath, O_WRONLY); + if (fd < 0) + goto fail; + if (dprintf(fd, "%llu\n", (unsigned long long)getpid()) < 0) + goto fail; + close(fd), fd = -1; + + /* Notify */ + if (write(notify_rw[1], &a_byte, 1) <= 0) + goto fail; + close(notify_rw[1]); + + return INIT_SUCCESS; fail: saved_errno = errno; if (fd >= 0) close(fd); if (notify_rw[0] >= 0) close(notify_rw[0]); if (notify_rw[1] >= 0) close(notify_rw[1]); errno = saved_errno; - return 1; + return INIT_FAILURE; } @@ -264,20 +281,16 @@ static int daemonise(int keep_stderr) * @param foreground Keep process in the foreground * @param keep_stderr Keep stderr open * @param query Was -q used, see `main` for description - * @return 1: Success - * 2: Normal failure - * 3: Libgamma failure - * 4: The service is already running - * Otherwise: The negative of the exit value the - * process should have and shall exit immediately + * @return An `enum init_status` value or an exit value */ -static int initialise(int full, int preserve, int foreground, int keep_stderr, int query) +static enum init_status initialise(int full, int preserve, int foreground, int keep_stderr, int query) { struct rlimit rlimit; - size_t i, j, n, n0; + size_t i, n; sigset_t mask; char* restrict sitename_dup = NULL; - int r; + int s, gerror; + enum init_status r; /* Zero out some memory so it can be destoried safely. */ memset(&site, 0, sizeof(site)); @@ -294,8 +307,8 @@ static int initialise(int full, int preserve, int foreground, int keep_stderr, i /* Set umask, reset signal handlers, and reset signal mask */ umask(0); - for (r = 1; r < _NSIG; r++) - signal(r, SIG_DFL); + for (s = 1; s < _NSIG; s++) + signal(s, SIG_DFL); if (sigfillset(&mask)) perror(argv0); else @@ -308,21 +321,19 @@ static int initialise(int full, int preserve, int foreground, int keep_stderr, i /* Go no further if we are just interested in the adjustment method and site */ if (query) - return 1; + return INIT_SUCCESS; /* Get site */ - if (sitename != NULL) - if (!(sitename_dup = memdup(sitename, strlen(sitename) + 1))) - goto fail; + if ((sitename != NULL) && !(sitename_dup = memdup(sitename, strlen(sitename) + 1))) + goto fail; if ((gerror = libgamma_site_initialise(&site, method, sitename_dup))) goto fail_libgamma; if (full) { /* Get PID file and socket pathname */ - if (!(pidpath = get_pidfile_pathname())) - goto fail; - if (!(socketpath = get_socket_pathname())) + if (!(pidpath = get_pidfile_pathname()) || + !(socketpath = get_socket_pathname())) goto fail; /* Create PID file */ @@ -330,35 +341,18 @@ static int initialise(int full, int preserve, int foreground, int keep_stderr, i { free(pidpath), pidpath = NULL; if (r == -2) - goto already_running; + return INIT_RUNNING; goto fail; } } - /* Get partitions */ - if (site.partitions_available) - if (!(partitions = calloc(site.partitions_available, sizeof(*partitions)))) - goto fail; - for (i = 0; i < site.partitions_available; i++) - { - if ((gerror = libgamma_partition_initialise(partitions + i, &site, i))) - goto fail_libgamma; - outputs_n += partitions[i].crtcs_available; - } - - /* Get CRTC:s */ - if (outputs_n) - if (!(crtcs = calloc(outputs_n, sizeof(*crtcs)))) - goto fail; - for (i = 0, j = n = 0; i < site.partitions_available; i++) - for (n0 = n, n += partitions[i].crtcs_available; j < n; j++) - if ((gerror = libgamma_crtc_initialise(crtcs + j, partitions + i, j - n0))) - goto fail_libgamma; + /* Get partitions and CRTC:s */ + if (initialise_crtcs() < 0) + goto fail; /* Get CRTC information */ - if (outputs_n) - if (!(outputs = calloc(outputs_n, sizeof(*outputs)))) - goto fail; + if (outputs_n && !(outputs = calloc(outputs_n, sizeof(*outputs)))) + goto fail; if (initialise_gamma_info() < 0) goto fail; free(crtcs), crtcs = NULL; @@ -370,9 +364,8 @@ static int initialise(int full, int preserve, int foreground, int keep_stderr, i store_gamma(); /* Preserve current gamma ramps at priority=0 if -p */ - if (preserve) - if (preserve_gamma() < 0) - goto fail; + if (preserve && (preserve_gamma() < 0)) + goto fail; if (full) { @@ -382,9 +375,8 @@ static int initialise(int full, int preserve, int foreground, int keep_stderr, i /* Get the real pathname of the process's binary, in case * it is relative, so we can re-execute without problem. */ - if ((*argv0 != '/') && strchr(argv0, '/')) - if (!(argv0_real = realpath(argv0, NULL))) - goto fail; + if ((*argv0 != '/') && strchr(argv0, '/') && !(argv0_real = realpath(argv0, NULL))) + goto fail; /* Change directory to / to avoid blocking umounting */ if (chdir("/") < 0) @@ -400,11 +392,7 @@ static int initialise(int full, int preserve, int foreground, int keep_stderr, i /* Place in the background unless -f */ if (full && (foreground == 0)) - { - r = daemonise(keep_stderr); - if (r != 1) - return r; - } + return daemonise(keep_stderr); else if (full) { /* Signal the spawner that the service is ready */ @@ -415,13 +403,12 @@ static int initialise(int full, int preserve, int foreground, int keep_stderr, i perror(argv0); } - return 1; - fail: - return 2; + return INIT_SUCCESS; fail_libgamma: - return 3; - already_running: - return 4; + libgamma_perror(argv0, gerror); + errno = 0; + fail: + return INIT_FAILURE; } @@ -442,11 +429,11 @@ static void destroy(int full) if (full && (outputs != NULL)) restore_gamma(); + state_destroy(); free(socketpath); if (full && (pidpath != NULL)) unlink(pidpath); free(pidpath); - state_destroy(); } @@ -699,6 +686,69 @@ static int print_method_and_site(int query) /** + * Reexecute the server + * + * Returns only on failure + * + * @param preserve Did -p appear on the comment line? + * @return Pathname of file where the state is stored, + * `NULL` if the state is in tact + */ +static char* reexecute(int preserve) +{ + char* statefile = NULL; + char* statebuffer = NULL; + size_t buffer_size; + int fd = -1, saved_errno; + + statefile = get_state_pathname(); + if (statefile == NULL) + goto fail; + + buffer_size = marshal(NULL); + statebuffer = malloc(buffer_size); + if (statebuffer == NULL) + goto fail; + if (marshal(statebuffer) != buffer_size) + { + fprintf(stderr, "%s: internal error", argv0); + errno = 0; + goto fail; + } + + fd = open(statefile, O_CREAT, S_IRUSR | S_IWUSR); + if (fd < 0) + goto fail; + + if (nwrite(fd, statebuffer, buffer_size) != buffer_size) + goto fail; + free(statebuffer), statebuffer = NULL; + + if ((close(fd) < 0) && (fd = -1, errno != EINTR)) + goto fail; + fd = -1; + + destroy(0); + + execlp(argv0_real ? argv0_real : argv0, argv0, "-#", statefile, preserve ? "-p" : NULL, NULL); + saved_errno = errno; + free(argv0_real), argv0_real = NULL; + errno = saved_errno; + return statefile; + + fail: + saved_errno = errno; + free(statebuffer); + if (fd >= 0) + close(fd); + if (statefile != NULL) + unlink(statefile), free(statefile); + errno = saved_errno; + return NULL; +} + + +/** * Print usage information and exit */ #if defined(__GNU__) || defined(__clang__) @@ -762,7 +812,6 @@ int main(int argc, char** argv) { int rc = 1, preserve = 0, foreground = 0, keep_stderr = 0, query = 0, r; char* statefile = NULL; - char* statebuffer = NULL; ARGBEGIN { @@ -778,18 +827,10 @@ int main(int argc, char** argv) if (method < 0) goto fail; break; - case 'p': - preserve = 1; - break; - case 'f': - foreground = 1; - break; - case 'k': - keep_stderr = 1; - break; - case 'q': - query = 1 + !!query; - break; + case 'p': preserve = 1; break; + case 'f': foreground = 1; break; + case 'k': keep_stderr = 1; break; + case 'q': query = 1 + !!query; break; case '#': /* Internal, do not document */ statefile = EARGF(usage()); break; @@ -800,21 +841,14 @@ int main(int argc, char** argv) if (argc > 0) usage(); - restart: /* If C had comefrom: comefrom reexec_failure; */ + restart: switch ((r = initialise(statefile == NULL, preserve, foreground, keep_stderr, query))) { - case 1: - break; - case 2: - goto fail; - case 3: - goto fail_libgamma; - case 4: - rc = 2; - goto fail; - default: - return -r; + case INIT_SUCCESS: break; + case INIT_RUNNING: rc = 2; /* fall through */ + case INIT_FAILURE: goto fail; + default: return r; } if (query) @@ -828,60 +862,35 @@ int main(int argc, char** argv) { if (unmarshal_and_merge_state(statefile) < 0) goto fail; + if (reexec) + free(statefile); unlink(statefile), statefile = NULL; - reexec = 0; /* See `if (reexec && !terminate)` */ + reexec = 0; /* See `if (reexec && !terminate)` below */ } + reenter_loop: if (main_loop() < 0) goto fail; if (reexec && !terminate) { - size_t buffer_size; - int fd; - - /* `reexec = 0;` is done later in case of re-execute failure, - * since it determines whether `statefile` shall be freed. */ - - statefile = get_state_pathname(); - if (statefile == NULL) - goto fail; - - buffer_size = marshal(NULL); - statebuffer = malloc(buffer_size); - if (statebuffer == NULL) - goto fail; - if (marshal(statebuffer) != buffer_size) - abort(); - - fd = open(statefile, O_CREAT, S_IRUSR | S_IWUSR); - if (fd < 0) - goto fail; - - if (nwrite(fd, statebuffer, buffer_size) != buffer_size) + if ((statefile = reexecute(preserve))) { perror(argv0); - close(fd); - errno = 0; - goto fail; + fprintf(stderr, "%s: restoring state without re-executing\n", argv0); + /* `reexec = 0;` is done later in case of re-execute failure, + * since it determines whether `statefile` shall be freed. */ + goto restart; } - free(statebuffer), statebuffer = NULL; - - if ((close(fd) < 0) && (errno != EINTR)) - goto fail; - - destroy(0); - - execlp(argv0_real ? argv0_real : argv0, argv0, "-#", statefile, preserve ? "-p" : NULL, NULL); perror(argv0); - fprintf(stderr, "%s: restoring state without re-executing\n", argv0); - free(argv0_real), argv0_real = NULL; - goto restart; + fprintf(stderr, "%s: continuing without re-executing\n", argv0); + reexec = 0; + goto reenter_loop; } - rc = 0; done: - free(statebuffer); + rc = 0; + deinit: if (statefile) unlink(statefile); if (reexec) @@ -891,9 +900,6 @@ int main(int argc, char** argv) fail: if (errno != 0) perror(argv0); - goto done; - fail_libgamma: - libgamma_perror(argv0, gerror); - goto done; + goto deinit; } |