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-rw-r--r--src/coopgammad.c386
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;
}