/** * gammad -- Cooperative gamma server * Copyright (C) 2016 Mattias Andrée (maandree@kth.se) * * This library is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This library 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this library. If not, see . */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include "arg.h" #include "output.h" #include "util.h" #include "server.h" /** * The name of the process */ char* argv0; /** * Array of all outputs */ struct output* outputs = NULL; /** * The nubmer of elements in `outputs` */ size_t outputs_n = 0; /** * The server socket's file descriptor */ int socketfd = -1; /** * The pathname of the PID file */ char* pidpath = NULL; /** * The pathname of the socket */ char* socketpath = NULL; /** * Error code returned by libgamma */ int gerror; /** * Initialisation stage * * Used to keep track on what to destroy, of those things that * must only be destroyed if they have been initialised */ int init_stage = 0; /** * The libgamma site state */ libgamma_site_state_t site; /** * The libgamma partition states */ libgamma_partition_state_t* partitions = NULL; /** * The libgamma CRTC states */ libgamma_crtc_state_t* crtcs = NULL; /** * Has the process receive a signal * telling it to re-execute? */ volatile sig_atomic_t reexec = 0; /** * Has the process receive a signal * telling it to terminate? */ volatile sig_atomic_t terminate = 0; /** * Called when the process receives * a signal telling it to re-execute * * @param signo The received signal */ static void sig_reexec(int signo) { reexec = 1; (void) signo; } /** * Called when the process receives * a signal telling it to terminate * * @param signo The received signal */ static void sig_terminate(int signo) { terminate = 1; (void) signo; } /** * Get the pathname of the runtime file * * @param suffix The suffix for the file * @return The pathname of the file, `NULL` on error */ static char* get_pathname(const char* suffix) { const char* rundir = getenv("XDG_RUNTIME_DIR"); const char* username = ""; char* name = NULL; char* p; char* rc; struct passwd* pw; size_t n; int saved_errno; if (site.site) { name = memdup(site.site, strlen(site.site) + 1); if (name == NULL) goto fail; } else if ((name = libgamma_method_default_site(site.method))) { name = memdup(name, strlen(name) + 1); if (name == NULL) goto fail; } if (name != NULL) switch (site.method) { case LIBGAMMA_METHOD_X_RANDR: case LIBGAMMA_METHOD_X_VIDMODE: if ((p = strrchr(name, ':'))) if ((p = strchr(p, '.'))) *p = '\0'; default: break; } if (!rundir || !*rundir) rundir = "/tmp"; if ((pw = getpwuid(getuid()))) username = pw->pw_name ? pw->pw_name : ""; n = sizeof("/.gammad/~/.") + 3 * sizeof(int); n += strlen(rundir) + strlen(username) + strlen(name) + strlen(suffix); if (!(rc = malloc(n))) goto fail; sprintf(rc, "%s/.gammad/~%s/%i%s%s%s", rundir, username, site.method, name ? "." : "", name ? name : "", suffix); return rc; fail: saved_errno = errno; free(name); errno = saved_errno; return NULL; } /** * Get the pathname of the socket * * @return The pathname of the socket, `NULL` on error */ static inline char* get_socket_pathname(void) { return get_pathname(".socket"); } /** * Get the pathname of the PID file * * @return The pathname of the PID file, `NULL` on error */ static inline char* get_pidfile_pathname(void) { return get_pathname(".pid"); } /** * Parse adjustment method name (or stringised number) * * @param arg The adjustment method name (or stringised number) * @return The adjustment method, -1 (negative) on error */ static int get_method(char* arg) { #if LIBGAMMA_METHOD_MAX > 5 # warning libgamma has added more adjustment methods #endif char* p; if (!strcmp(arg, "dummy")) return LIBGAMMA_METHOD_DUMMY; if (!strcmp(arg, "randr")) return LIBGAMMA_METHOD_X_RANDR; if (!strcmp(arg, "vidmode")) return LIBGAMMA_METHOD_X_VIDMODE; if (!strcmp(arg, "drm")) return LIBGAMMA_METHOD_LINUX_DRM; if (!strcmp(arg, "gdi")) return LIBGAMMA_METHOD_W32_GDI; if (!strcmp(arg, "quartz")) return LIBGAMMA_METHOD_QUARTZ_CORE_GRAPHICS; if (!*arg || (/* avoid overflow: */ strlen(arg) > 4)) goto bad; for (p = arg; *p; p++) if (('0' > *p) || (*p > '9')) goto bad; return atoi(arg); bad: fprintf(stderr, "%s: unrecognised adjustment method name: %s\n", argv0, arg); errno = 0; return -1; } /** * Get the name of a CRTC * * @param info Information about the CRTC * @param crtc libgamma's state for the CRTC * @return The name of the CRTC, `NULL` on error */ static char* get_crtc_name(libgamma_crtc_information_t* info, libgamma_crtc_state_t* crtc) { if ((info->edid_error == 0) && (info->edid != NULL)) return libgamma_behex_edid(info->edid, info->edid_length); else if ((info->connector_name_error == 0) && (info->connector_name != NULL)) { char* name = malloc(3 * sizeof(size_t) + strlen(info->connector_name) + 2); if (name != NULL) sprintf(name, "%zu.%s", crtc->partition->partition, info->connector_name); return name; } else { char* name = malloc(2 * 3 * sizeof(size_t) + 2); if (name != NULL) sprintf(name, "%zu.%zu", crtc->partition->partition, crtc->crtc); return name; } } /** * Check whether a PID file is outdated * * @param pidfile The PID file * @param token An environment variable (including both key and value) * that must exist in the process if it is a gammad process * @return -1: An error occurred * 0: The service is already running * 1: The PID file is outdated */ static int is_pidfile_reusable(const char* pidfile, const char* token) { /* PORTERS: /proc/$PID/environ is Linux specific */ char temp[sizeof("/proc//environ") + 3 * sizeof(pid_t)]; int fd = -1, saved_errno, tries = 0; char* content = NULL; char* p; pid_t pid = 0; size_t n; #if defined(HAVE_LINUX_PROCFS) char* end; #else (void) token; #endif /* Get PID */ retry: fd = open(pidfile, O_RDONLY); if (fd < 0) return -1; content = nread(fd, &n); if (content == NULL) goto fail; close(fd), fd = -1; if (n == 0) { if (++tries > 1) goto bad; msleep(100); /* 1 tenth of a second */ goto retry; } if (('0' > content[0]) || (content[0] > '9')) goto bad; if ((content[0] == '0') && ('0' <= content[1]) && (content[1] <= '9')) goto bad; for (p = content; *p; p++) if (('0' <= *p) && (*p <= '9')) pid = pid * 10 + (*p & 15); else break; if (*p++ != '\n') goto bad; if (*p) goto bad; if ((size_t)(content - p) != n) goto bad; sprintf(temp, "%llu", (unsigned long long)pid); if (strcmp(content, temp)) goto bad; /* Validate PID */ #if defined(HAVE_LINUX_PROCFS) sprintf(temp, "/proc/%llu/environ", (unsigned long long)pid); fd = open(temp, O_RDONLY); if (fd < 0) return ((errno == ENOENT) || (errno == EACCES)) ? 1 : -1; content = nread(fd, &n); if (content == NULL) goto fail; close(fd), fd = -1; for (end = (p = content) + n; p != end; p = strchr(p, '\0') + 1) if (!strcmp(p, token)) return 0; #else if ((kill(pid, 0) == 0) || (errno == EINVAL)) return 0; #endif return 1; bad: fprintf(stderr, "%s: pid file contain invalid content: %s\n", argv0, pidfile); errno = 0; return -1; fail: saved_errno = errno; free(content); if (fd >= 0) close(fd); errno = saved_errno; return -1; } /** * Create PID file * * @param pidfile The pathname of the PID file * @return Zero on success, -1 on error, * -2 if the service is already running */ static int create_pidfile(char* pidfile) { int fd, r, saved_errno; char* p; char* token; /* Create token used to validate the service. */ token = malloc(sizeof("GAMMAD_PIDFILE_TOKEN=") + strlen(pidfile)); if (token == NULL) return -1; sprintf(token, "GAMMAD_PIDFILE_TOKEN=%s", pidfile); if (putenv(token)) return -1; /* Create PID file's directory. */ for (p = pidfile; *p == '/'; p++); while ((p = strchr(p, '/'))) { *p = '\0'; if (mkdir(pidfile, 0644) < 0) if (errno != EEXIST) return -1; *p++ = '/'; } /* Create PID file. */ retry: fd = open(pidfile, O_CREAT | O_EXCL, 0644); if (fd < 0) { if (errno == EINTR) goto retry; if (errno != EEXIST) return -1; r = is_pidfile_reusable(pidfile, token); if (r > 0) { unlink(pidfile); goto retry; } else if (r < 0) goto fail; fprintf(stderr, "%s: service is already running\n", argv0); errno = 0; return -2; } /* Write PID to PID file. */ if (dprintf(fd, "%llu\n", (unsigned long long)getpid()) < 0) goto fail; /* Done */ if (close(fd) < 0) if (errno != EINTR) return -1; return 0; fail: saved_errno = errno; close(fd); unlink(pidfile); errno = saved_errno; return -1; } /** * Initialise the process * * @param method The adjustment method, -1 for automatic * @param sitename The site's name, may be `NULL` * @param preserve Preserve current gamma ramps at priority 0 * @param foreground Keep process in the foreground * @param keep_stderr Keep stderr open * @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 */ static int initialise(int method, const char *sitename, int preserve, int foreground, int keep_stderr) { struct sockaddr_un address; struct rlimit rlimit; size_t i, j, n, n0; sigset_t mask; char* sitename_dup = NULL; int r; /* Zero out some memory so it can be destoried safely. */ memset(&site, 0, sizeof(site)); /* Close all file descriptors above stderr */ if (getrlimit(RLIMIT_NOFILE, &rlimit) || (rlimit.rlim_cur == RLIM_INFINITY)) n = 4 << 10; else n = (size_t)(rlimit.rlim_cur); for (i = STDERR_FILENO + 1; i < n; i++) close((int)i); /* Set umask, reset signal handlers, and reset signal mask */ umask(0); for (r = 1; r < _NSIG; r++) signal(r, SIG_DFL); if (sigfillset(&mask)) perror(argv0); else sigprocmask(SIG_UNBLOCK, &mask, NULL); /* Get method */ if ((method < 0) && (libgamma_list_methods(&method, 1, 0) < 1)) return fprintf(stderr, "%s: no adjustment method available\n", argv0), -1; /* Get site */ if (sitename != NULL) if (!(sitename_dup = memdup(sitename, strlen(sitename) + 1))) goto fail; if ((gerror = libgamma_site_initialise(&site, method, sitename_dup))) goto fail_libgamma; /* Get PID file and socket pathname */ if (!(pidpath = get_pidfile_pathname())) goto fail; if (!(socketpath = get_socket_pathname())) goto fail; /* Create PID file */ if ((r = create_pidfile(pidpath)) < 0) { free(pidpath), pidpath = NULL; if (r == -2) goto already_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 CRTC information */ if (outputs_n) if (!(outputs = calloc(outputs_n, sizeof(*outputs)))) goto fail; for (i = 0; i < outputs_n; i++) { libgamma_crtc_information_t info; int saved_errno; libgamma_get_crtc_information(&info, crtcs + i, LIBGAMMA_CRTC_INFO_EDID | LIBGAMMA_CRTC_INFO_MACRO_RAMP | LIBGAMMA_CRTC_INFO_GAMMA_SUPPORT | LIBGAMMA_CRTC_INFO_CONNECTOR_NAME); outputs[i].depth = info.gamma_depth_error ? 0 : info.gamma_depth; outputs[i].red_size = info.gamma_size_error ? 0 : info.red_gamma_size; outputs[i].green_size = info.gamma_size_error ? 0 : info.green_gamma_size; outputs[i].blue_size = info.gamma_size_error ? 0 : info.blue_gamma_size; outputs[i].supported = info.gamma_support_error ? 0 : info.gamma_support; if (outputs[i].depth == 0 || outputs[i].red_size == 0 || outputs[i].green_size == 0 || outputs[i].blue_size == 0) outputs[i].supported = 0; outputs[i].name = get_crtc_name(&info, crtcs + i); saved_errno = errno; outputs[i].crtc = crtcs + i; libgamma_crtc_information_destroy(&info); outputs[i].ramps_size = outputs[i].red_size + outputs[i].green_size + outputs[i].blue_size; /* outputs[i].ramps_size will be multipled by the stop-size later */ errno = saved_errno; if (outputs[i].name == NULL) goto fail; } free(crtcs), crtcs = NULL; /* Sort outputs */ qsort(outputs, outputs_n, sizeof(*outputs), output_cmp_by_name); /* Load current gamma ramps */ #define LOAD_RAMPS(SUFFIX, MEMBER) \ do \ { \ libgamma_gamma_ramps##SUFFIX##_initialise(&(outputs[i].saved_ramps.MEMBER)); \ gerror = libgamma_crtc_get_gamma_ramps##SUFFIX(outputs[i].crtc, &(outputs[i].saved_ramps.MEMBER)); \ if (gerror) \ { \ libgamma_perror(argv0, gerror); \ outputs[i].supported = LIBGAMMA_NO; \ libgamma_gamma_ramps##SUFFIX##_destroy(&(outputs[i].saved_ramps.MEMBER)); \ memset(&(outputs[i].saved_ramps.MEMBER), 0, sizeof(outputs[i].saved_ramps.MEMBER)); \ } \ } \ while (0) for (i = 0; i < outputs_n; i++) if (outputs[i].supported != LIBGAMMA_NO) switch (outputs[i].depth) { case 8: outputs[i].ramps_size *= sizeof(uint8_t); LOAD_RAMPS(8, u8); break; case 16: outputs[i].ramps_size *= sizeof(uint16_t); LOAD_RAMPS(16, u16); break; case 32: outputs[i].ramps_size *= sizeof(uint32_t); LOAD_RAMPS(32, u32); break; default: outputs[i].depth = 64; /* fall through */ case 64: outputs[i].ramps_size *= sizeof(uint64_t); LOAD_RAMPS(64, u64); break; case -1: outputs[i].ramps_size *= sizeof(float); LOAD_RAMPS(f, f); break; case -2: outputs[i].ramps_size *= sizeof(double); LOAD_RAMPS(d, d); break; } /* Preserve current gamma ramps at priority=0 if -p */ if (preserve) for (i = 0; i < outputs_n; i++) { struct filter filter = { .client = -1, .crtc = NULL, .priority = 0, .class = NULL, .lifespan = LIFESPAN_UNTIL_REMOVAL, .ramps = NULL }; outputs[i].table_filters = calloc(4, sizeof(*(outputs[i].table_filters))); outputs[i].table_sums = calloc(4, sizeof(*(outputs[i].table_sums))); outputs[i].table_alloc = 4; outputs[i].table_size = 1; filter.class = memdup(PKGNAME "::" COMMAND "::preserved", sizeof(PKGNAME "::" COMMAND "::preserved")); if (filter.class == NULL) goto fail; filter.ramps = memdup(outputs[i].saved_ramps.u8.red, outputs[i].ramps_size); if (filter.ramps == NULL) goto fail; outputs[i].table_filters[0] = filter; COPY_RAMP_SIZES(&(outputs[i].table_sums[0].u8), outputs + i); if (!gamma_ramps_unmarshal(outputs[i].table_sums, outputs[i].saved_ramps.u8.red, outputs[i].ramps_size)) goto fail; } /* Create socket and start listening */ address.sun_family = AF_UNIX; if (strlen(socketpath) >= sizeof(address.sun_path)) { errno = ENAMETOOLONG; goto fail; } strcpy(address.sun_path, socketpath); unlink(socketpath); if ((socketfd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) goto fail; if (fchmod(socketfd, S_IRWXU) < 0) goto fail; if (bind(socketfd, (struct sockaddr*)(&address), sizeof(address)) < 0) goto fail; if (listen(socketfd, SOMAXCONN) < 0) goto fail; /* Change directory to / to avoid blocking umounting */ if (chdir("/") < 0) perror(argv0); /* Set up signal handlers */ if (signal(SIGUSR1, sig_reexec) == SIG_ERR) goto fail; if (signal(SIGTERM, sig_terminate) == SIG_ERR) goto fail; /* Initialise the server */ if (server_initialise() < 0) goto fail; init_stage++; /* Place in the background unless -f */ if (foreground == 0) { pid_t pid; int fd = -1, saved_errno; int notify_rw[2] = { -1, -1 }; char a_byte = 0; ssize_t got; if (pipe(notify_rw) < 0) goto fail; if (notify_rw[0] <= STDERR_FILENO) if ((notify_rw[0] = dup2atleast(notify_rw[0], STDERR_FILENO + 1)) < 0) goto fail_background; if (notify_rw[1] <= STDERR_FILENO) if ((notify_rw[1] = dup2atleast(notify_rw[1], STDERR_FILENO + 1)) < 0) goto fail_background; switch ((pid = fork())) { case -1: goto fail_background; case 0: /* Child */ close(notify_rw[0]), notify_rw[0] = -1; if (setsid() < 0) goto fail_background; switch ((pid = fork())) { case -1: goto fail_background; 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_background; if (dprintf(fd, "%llu\n", (unsigned long long)getpid()) < 0) goto fail_background; close(fd), fd = -1; /* Notify */ if (write(notify_rw[1], &a_byte, 1) <= 0) goto fail_background; close(notify_rw[1]); break; default: /* Parent */ return 0; } break; default: /* Parent */ close(notify_rw[1]), notify_rw[1] = -1; got = read(notify_rw[0], &a_byte, 1); if (got < 0) goto fail_background; close(notify_rw[0]); return -(got == 0); } goto done_background; fail_background: 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; done_background:; } else { /* Signal the spawner that the service is ready */ close(STDOUT_FILENO); /* Avoid potential catastrophes that would occur if a library that is being * used was so mindless as to write to stdout. */ if (dup2(STDERR_FILENO, STDOUT_FILENO) < 0) perror(argv0); } return 1; fail: return 2; fail_libgamma: return 3; already_running: return 4; } /** * Deinitialise the process */ static void destroy(void) { size_t i; if (init_stage >= 1) server_destroy(1); if (socketfd >= 0) { shutdown(socketfd, SHUT_RDWR); close(socketfd); unlink(socketpath); } #define RESTORE_RAMPS(SUFFIX, MEMBER) \ do \ if (outputs[i].saved_ramps.MEMBER.red != NULL) \ { \ gerror = libgamma_crtc_set_gamma_ramps##SUFFIX(outputs[i].crtc, outputs[i].saved_ramps.MEMBER); \ if (gerror) \ libgamma_perror(argv0, gerror); \ } \ while (0) if (outputs != NULL) for (i = 0; i < outputs_n; i++) { if (outputs[i].supported != LIBGAMMA_NO) switch (outputs[i].depth) { case 8: RESTORE_RAMPS(8, u8); break; case 16: RESTORE_RAMPS(16, u16); break; case 32: RESTORE_RAMPS(32, u32); break; case 64: RESTORE_RAMPS(64, u64); break; case -1: RESTORE_RAMPS(f, f); break; case -2: RESTORE_RAMPS(d, d); break; default: break; /* impossible */ } if (crtcs == NULL) libgamma_crtc_destroy(outputs[i].crtc + i); output_destroy(outputs + i); } free(outputs); if (crtcs != NULL) for (i = 0; i < outputs_n; i++) libgamma_crtc_destroy(crtcs + i); free(crtcs); if (partitions != NULL) for (i = 0; i < site.partitions_available; i++) libgamma_partition_destroy(partitions + i); free(partitions); libgamma_site_destroy(&site); free(socketpath); if (pidpath) unlink(pidpath); free(pidpath); } /** * Print usage information and exit */ static void usage(void) { printf("Usage: %s [-m method] [-s site] [-kfp]\n", argv0); exit(1); } /** * Must not be started without stdin, stdout, or stderr (may be /dev/null) * * The process closes stdout when the socket has been created * * @signal SIGUSR1 Re-execute to updated process image * @signal SIGTERM Terminate the process gracefully * * @param argc The number of elements in `argv` * @param argv Command line arguments. Recognised options: * -s SITENAME * The site to which to connect * -m METHOD * Adjustment method name or adjustment method number * -p * Preserve current gamma ramps at priority 0 * -f * Do not fork the process into the background * -k * Keep stderr open * @return 0: Successful * 1: An error occurred * 2: Already running */ int main(int argc, char** argv) { int method = -1, rc = 1, preserve = 0, foreground = 0, keep_stderr = 0, r; char* sitename = NULL; ARGBEGIN { case 's': sitename = EARGF(usage()); break; case 'm': method = get_method(EARGF(usage())); if (method < 0) goto fail; break; case 'p': preserve = 1; break; case 'f': foreground = 1; break; case 'k': keep_stderr = 1; break; default: usage(); } ARGEND; if (argc > 0) usage(); switch ((r = initialise(method, sitename, preserve, foreground, keep_stderr))) { case 1: break; case 2: goto fail; case 3: goto fail_libgamma; case 4: rc = 2; goto fail; default: return -r; } rc = 0; done: destroy(); return rc; fail: if (errno != 0) perror(argv0); goto done; fail_libgamma: libgamma_perror(argv0, gerror); goto done; }