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-rw-r--r--src/mds.c260
1 files changed, 128 insertions, 132 deletions
diff --git a/src/mds.c b/src/mds.c
index c466846..12684b9 100644
--- a/src/mds.c
+++ b/src/mds.c
@@ -74,9 +74,6 @@ int main(int argc_, char** argv_)
int j, r;
-#define exit_if(CONDITION, INSTRUCTION) if (CONDITION) { INSTRUCTION return 1; }
-
-
argc = argc_;
argv = argv_;
@@ -110,6 +107,7 @@ int main(int argc_, char** argv_)
if (create_directory_root(MDS_RUNTIME_ROOT_DIRECTORY))
return 1;
+
/* Determine display index. */
for (display = 0; display < DISPLAY_MAX; display++)
{
@@ -137,11 +135,8 @@ int main(int argc_, char** argv_)
eprint("sorry, too many displays on the system."););
/* Yes, the directory could have been removed, but it probably was not. */
-#undef exit_if
-
/* Create PID file. */
- if ((f = fopen(pathname, "w")) == NULL)
- goto pfail;
+ fail_if ((f = fopen(pathname, "w")) == NULL);
xsnprintf(piddata, "%u\n", getpid());
if (fwrite(piddata, 1, strlen(piddata), f) < strlen(piddata))
{
@@ -156,15 +151,15 @@ int main(int argc_, char** argv_)
perror(*argv);
/* Create data storage directory. */
- if (create_directory_root(MDS_STORAGE_ROOT_DIRECTORY))
- goto fail;
xsnprintf(pathname, "%s/%u.data", MDS_STORAGE_ROOT_DIRECTORY, display);
- if (unlink_recursive(pathname) || create_directory_user(pathname))
- goto fail;
+ fail_if (create_directory_root(MDS_STORAGE_ROOT_DIRECTORY));
+ fail_if (unlink_recursive(pathname));
+ fail_if (create_directory_user(pathname));
+
/* Save MDS_DISPLAY environment variable. */
xsnprintf(pathname, /* Excuse the reuse without renaming. */
- ":%u", display);
+ ":%u", display);
setenv(DISPLAY_ENV, pathname, 1);
/* Create display socket. */
@@ -173,13 +168,12 @@ int main(int argc_, char** argv_)
strcpy(address.sun_path, pathname);
unlink(pathname);
fd = socket(AF_UNIX, SOCK_STREAM, 0);
- if (fchmod(fd, S_IRWXU) < 0) goto pfail;
- if (bind(fd, (struct sockaddr*)(&address), sizeof(address)) < 0) goto pfail;
- if (chown(pathname, getuid(), NOBODY_GROUP_GID) < 0) goto pfail;
+ fail_if (fchmod(fd, S_IRWXU) < 0);
+ fail_if (bind(fd, (struct sockaddr*)(&address), sizeof(address)) < 0);
+ fail_if (chown(pathname, getuid(), NOBODY_GROUP_GID) < 0);
/* Start listening on socket. */
- if (listen(fd, SOMAXCONN) < 0)
- goto pfail;
+ fail_if (listen(fd, SOMAXCONN) < 0);
/* Start master server and respawn it if it crashes. */
rc = spawn_and_respawn_server(fd);
@@ -207,7 +201,6 @@ int main(int argc_, char** argv_)
pfail:
perror(*argv);
- fail:
rc = 1;
goto done;
}
@@ -271,6 +264,25 @@ pid_t parse_pid_t(const char* str, size_t n)
}
+
+/**
+ * Drop privileges and change execution image into the master server's image.
+ * This function will only return on error.
+ *
+ * @param child_args Command line arguments for the new image
+ */
+static void exec_master_server(char** child_args)
+{
+ /* Drop privileges. They most not be propagated non-authorised components. */
+ /* setgid should not be set, but just to be safe we are restoring both user and group. */
+ if (drop_privileges())
+ return;
+
+ /* Start master server. */
+ execv(master_server, child_args);
+}
+
+
/**
* Start master server and respawn it if it crashes
*
@@ -302,83 +314,68 @@ int spawn_and_respawn_server(int fd)
# error LIBEXEC_ARGC_EXTRA_LIMIT is too small, need at least 2.
#endif
- for (;;)
+
+ respawn:
+
+ pid = fork();
+ if (pid == (pid_t)-1)
+ goto pfail;
+
+ if (pid == 0) /* Child. */
{
- pid = fork();
- if (pid == (pid_t)-1)
- {
- perror(*argv);
- goto fail;
- }
-
- if (pid)
- {
- /* Get the current time. (Start of child process.) */
- time_error = (monotone(&time_start) < 0);
- if (time_error)
- perror(*argv);
-
- /* Wait for master server to die. */
- if (waitpid(pid, &status, 0) == (pid_t)-1)
- {
- perror(*argv);
- goto fail;
- }
-
- /* If the server exited normally or SIGTERM, do not respawn. */
- if (WIFEXITED(status) || (WEXITSTATUS(status) && WTERMSIG(status)))
- break;
-
- /* Get the current time. (End of child process.) */
- time_error |= (monotone(&time_end) < 0);
-
- /* Do not respawn if we could not read the time. */
- if (time_error)
- {
- perror(*argv);
- eprintf("%s died abnormally, not respawning because we could not read the time.", master_server);
- goto fail;
- }
-
- /* Respawn if the server did not die too fast. */
- if (time_end.tv_sec - time_start.tv_sec >= RESPAWN_TIME_LIMIT_SECONDS)
- eprintf("%s died abnormally, respawning.", master_server);
- else
- {
- eprintf("%s died abnormally, died too fast, not respawning.", master_server);
- goto fail;
- }
-
- if (first_spawn)
- {
- first_spawn = 0;
- free(child_args[argc + 0]);
- child_args[argc + 0] = strdup("--respawn");
- if (child_args[argc + 0] == NULL)
- {
- perror(*argv);
- goto fail;
- }
- }
- }
- else
- {
- rc++;
- /* Drop privileges. They most not be propagated non-authorised components. */
- /* setgid should not be set, but just to be safe we are restoring both user and group. */
- if (drop_privileges())
- {
- perror(*argv);
- goto fail;
- }
-
- /* Start master server. */
- execv(master_server, child_args);
- perror(*argv);
- goto fail;
- }
+ rc++;
+ exec_master_server(child_args);
+ goto pfail;
+ }
+
+
+ /* Parent. */
+
+ /* Get the current time. (Start of child process.) */
+ if ((time_error = (monotone(&time_start) < 0)))
+ perror(*argv);
+
+ /* Wait for master server to die. */
+ if (waitpid(pid, &status, 0) == (pid_t)-1)
+ goto pfail;
+
+ /* If the server exited normally or SIGTERM, do not respawn. */
+ if (WIFEXITED(status) || (WEXITSTATUS(status) && WTERMSIG(status)))
+ goto done; /* Child exited normally, stop. */
+
+ /* Get the current time. (End of child process.) */
+ time_error |= (monotone(&time_end) < 0);
+
+ /* Do not respawn if we could not read the time. */
+ if (time_error)
+ {
+ perror(*argv);
+ eprintf("%s died abnormally, not respawning because we could not read the time.", master_server);
+ goto fail;
+ }
+
+ /* Respawn if the server did not die too fast. */
+ if (time_end.tv_sec - time_start.tv_sec >= RESPAWN_TIME_LIMIT_SECONDS)
+ eprintf("%s died abnormally, respawning.", master_server);
+ else
+ {
+ eprintf("%s died abnormally, died too fast, not respawning.", master_server);
+ goto fail;
}
+ if (first_spawn)
+ {
+ first_spawn = 0;
+ free(child_args[argc + 0]);
+ child_args[argc + 0] = strdup("--respawn");
+ if (child_args[argc + 0] == NULL)
+ goto pfail;
+ }
+
+ goto respawn;
+
+
+ done:
rc--;
fail:
rc++;
@@ -387,6 +384,10 @@ int spawn_and_respawn_server(int fd)
if (rc == 2)
_exit(1);
return rc;
+
+ pfail:
+ perror(*argv);
+ goto fail;
}
@@ -411,26 +412,22 @@ int create_directory_root(const char* pathname)
}
}
else
- {
- /* Directory is missing, create it. */
- if (mkdir(pathname, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH) < 0)
- {
- if (errno != EEXIST) /* Unlikely race condition. */
- {
- perror(*argv);
- return 1;
- }
- }
- else
- /* Set ownership. */
- if (chown(pathname, ROOT_USER_UID, ROOT_GROUP_GID) < 0)
- {
- perror(*argv);
- return 1;
- }
- }
+ /* Directory is missing, create it. */
+ if (mkdir(pathname, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH) < 0)
+ {
+ if (errno != EEXIST) /* Unlikely race condition. */
+ goto pfail;
+ }
+ else
+ /* Set ownership. */
+ if (chown(pathname, ROOT_USER_UID, ROOT_GROUP_GID) < 0)
+ goto pfail;
return 0;
+
+ pfail:
+ perror(*argv);
+ return 1;
}
@@ -496,37 +493,36 @@ int unlink_recursive(const char* pathname)
int errno_ = errno;
struct stat _attr;
if (stat(pathname, &_attr) < 0)
- return 0;
+ return 0; /* Directory does not exist. */
errno = errno_;
- perror(*argv);
- return 1;
+ goto pfail;
}
/* Remove the content of the directory. */
while ((file = readdir(dir)) != NULL)
- if (strcmp(file->d_name, ".") && strcmp(file->d_name, ".."))
- if (unlink(file->d_name) < 0)
- {
- if (errno == EISDIR)
- unlink_recursive(file->d_name);
- else
- {
- perror(*argv);
- rc = 1;
- goto done;
- }
- eprint("pop");
- }
+ if (strcmp(file->d_name, ".") &&
+ strcmp(file->d_name, "..") &&
+ (unlink(file->d_name) < 0))
+ {
+ if (errno != EISDIR)
+ goto pfail;
+ unlink_recursive(file->d_name);
+ eprint("pop");
+ }
/* Remvoe the drectory. */
if (rmdir(pathname) < 0)
- {
- perror(*argv);
- rc = 1;
- }
+ goto pfail;
- done:
- closedir(dir);
+ done:
+ if (dir != NULL)
+ closedir(dir);
return rc;
+
+
+ pfail:
+ perror(*argv);
+ rc = -1;
+ goto done;
}
generated by cgit v1.2.3-70-g09d2 (git 2.47.0) at 2024-11-26 03:07:03 +0000