Use a separate lockfile to lock the configuration directory.

[meshlink] / src / conf.c

diff --git a/src/conf.c b/src/conf.c
index ac4d71a2bc9ad1db5547eac56ba958c77900bc6c..7f92048ce30603245946a047a264172861a2e304 100644 (file)
--- a/src/conf.c
+++ b/src/conf.c
@@ -96,7 +96,7 @@ static void deltree(const char *dirname) {
        rmdir(dirname);
 }
 
-static bool sync_path(const char *pathname) {
+bool sync_path(const char *pathname) {
        assert(pathname);
 
        int fd = open(pathname, O_RDONLY);
@@ -153,11 +153,6 @@ bool config_init(meshlink_handle_t *mesh, const char *conf_subdir) {
                return true;
        }
 
-       if(mkdir(mesh->confbase, 0700) && errno != EEXIST) {
-               logger(mesh, MESHLINK_DEBUG, "Could not create directory %s: %s\n", mesh->confbase, strerror(errno));
-               return false;
-       }
-
        char path[PATH_MAX];
 
        // Create "current" sub-directory in the confbase
@@ -191,7 +186,7 @@ bool config_destroy(const char *confbase, const char *conf_subdir) {
        assert(conf_subdir);
 
        if(!confbase) {
-               return false;
+               return true;
        }
 
        struct stat st;
@@ -456,35 +451,42 @@ bool meshlink_confbase_exists(meshlink_handle_t *mesh) {
        return confbase_exists;
 }
 
-/// Lock the main configuration file.
+/// Lock the main configuration file. Creates confbase if necessary.
 bool main_config_lock(meshlink_handle_t *mesh) {
        if(!mesh->confbase) {
                return true;
        }
 
+       if(mkdir(mesh->confbase, 0700) && errno != EEXIST) {
+               logger(NULL, MESHLINK_ERROR, "Cannot create configuration directory %s: %s", mesh->confbase, strerror(errno));
+               meshlink_close(mesh);
+               meshlink_errno = MESHLINK_ESTORAGE;
+               return NULL;
+       }
+
        char path[PATH_MAX];
-       make_main_path(mesh, "current", path, sizeof(path));
+       snprintf(path, sizeof(path), "%s" SLASH "meshlink.lock", mesh->confbase);
 
-       mesh->conffile = fopen(path, "r");
+       mesh->lockfile = fopen(path, "w+");
 
-       if(!mesh->conffile) {
+       if(!mesh->lockfile) {
                logger(NULL, MESHLINK_ERROR, "Cannot not open %s: %s\n", path, strerror(errno));
                meshlink_errno = MESHLINK_ESTORAGE;
                return false;
        }
 
 #ifdef FD_CLOEXEC
-       fcntl(fileno(mesh->conffile), F_SETFD, FD_CLOEXEC);
+       fcntl(fileno(mesh->lockfile), F_SETFD, FD_CLOEXEC);
 #endif
 
 #ifdef HAVE_MINGW
        // TODO: use _locking()?
 #else
 
-       if(flock(fileno(mesh->conffile), LOCK_EX | LOCK_NB) != 0) {
+       if(flock(fileno(mesh->lockfile), LOCK_EX | LOCK_NB) != 0) {
                logger(NULL, MESHLINK_ERROR, "Cannot lock %s: %s\n", path, strerror(errno));
-               fclose(mesh->conffile);
-               mesh->conffile = NULL;
+               fclose(mesh->lockfile);
+               mesh->lockfile = NULL;
                meshlink_errno = MESHLINK_EBUSY;
                return false;
        }
@@ -496,9 +498,9 @@ bool main_config_lock(meshlink_handle_t *mesh) {
 
 /// Unlock the main configuration file.
 void main_config_unlock(meshlink_handle_t *mesh) {
-       if(mesh->conffile) {
-               fclose(mesh->conffile);
-               mesh->conffile = NULL;
+       if(mesh->lockfile) {
+               fclose(mesh->lockfile);
+               mesh->lockfile = NULL;
        }
 }
 
@@ -565,6 +567,12 @@ bool config_write_file(meshlink_handle_t *mesh, FILE *f, const config_t *config,
 
                if(chacha_poly1305_encrypt_iv96(ctx, seqbuf, config->buf, config->len, buf, &len)) {
                        success = fwrite(seqbuf, sizeof(seqbuf), 1, f) == 1 && fwrite(buf, len, 1, f) == 1;
+
+                       if(!success) {
+                               logger(mesh, MESHLINK_ERROR, "Cannot write config file: %s", strerror(errno));
+                       }
+
+                       meshlink_errno = MESHLINK_ESTORAGE;
                } else {
                        logger(mesh, MESHLINK_ERROR, "Cannot encrypt config file\n");
                        meshlink_errno = MESHLINK_ESTORAGE;
@@ -580,8 +588,15 @@ bool config_write_file(meshlink_handle_t *mesh, FILE *f, const config_t *config,
                return false;
        }
 
+       if(fflush(f)) {
+               logger(mesh, MESHLINK_ERROR, "Failed to flush file: %s", strerror(errno));
+               meshlink_errno = MESHLINK_ESTORAGE;
+               return false;
+       }
+
        if(fsync(fileno(f))) {
                logger(mesh, MESHLINK_ERROR, "Failed to sync file: %s\n", strerror(errno));
+               meshlink_errno = MESHLINK_ESTORAGE;
                return false;
        }
 
@@ -695,6 +710,7 @@ bool config_write(meshlink_handle_t *mesh, const char *conf_subdir, const char *
 
        if(!f) {
                logger(mesh, MESHLINK_ERROR, "Failed to open `%s': %s", tmp_path, strerror(errno));
+               meshlink_errno = MESHLINK_ESTORAGE;
                return false;
        }
 
@@ -704,19 +720,15 @@ bool config_write(meshlink_handle_t *mesh, const char *conf_subdir, const char *
                return false;
        }
 
-       if(fsync(fileno(f))) {
-               logger(mesh, MESHLINK_ERROR, "Failed to sync `%s': %s", tmp_path, strerror(errno));
-               fclose(f);
-               return false;
-       }
-
        if(fclose(f)) {
                logger(mesh, MESHLINK_ERROR, "Failed to close `%s': %s", tmp_path, strerror(errno));
+               meshlink_errno = MESHLINK_ESTORAGE;
                return false;
        }
 
        if(rename(tmp_path, path)) {
                logger(mesh, MESHLINK_ERROR, "Failed to rename `%s' to `%s': %s", tmp_path, path, strerror(errno));
+               meshlink_errno = MESHLINK_ESTORAGE;
                return false;
        }
 
@@ -771,6 +783,7 @@ bool main_config_write(meshlink_handle_t *mesh, const char *conf_subdir, const c
 
        if(!f) {
                logger(mesh, MESHLINK_ERROR, "Failed to open `%s': %s", tmp_path, strerror(errno));
+               meshlink_errno = MESHLINK_ESTORAGE;
                return false;
        }
 
@@ -780,20 +793,16 @@ bool main_config_write(meshlink_handle_t *mesh, const char *conf_subdir, const c
                return false;
        }
 
-       if(fsync(fileno(f))) {
-               logger(mesh, MESHLINK_ERROR, "Failed to sync `%s': %s", tmp_path, strerror(errno));
-               fclose(f);
-               return false;
-       }
-
        if(rename(tmp_path, path)) {
                logger(mesh, MESHLINK_ERROR, "Failed to rename `%s' to `%s': %s", tmp_path, path, strerror(errno));
+               meshlink_errno = MESHLINK_ESTORAGE;
                fclose(f);
                return false;
        }
 
        if(fclose(f)) {
                logger(mesh, MESHLINK_ERROR, "Failed to close `%s': %s", tmp_path, strerror(errno));
+               meshlink_errno = MESHLINK_ESTORAGE;
                return false;
        }
 
@@ -859,7 +868,19 @@ bool invitation_read(meshlink_handle_t *mesh, const char *conf_subdir, const cha
 
        fclose(f);
 
-       unlink(used_path);
+       if(unlink(used_path)) {
+               logger(mesh, MESHLINK_ERROR, "Failed to unlink `%s': %s", path, strerror(errno));
+               return false;
+       }
+
+       snprintf(path, sizeof(path), "%s" SLASH "%s" SLASH "invitations", mesh->confbase, conf_subdir);
+
+       if(!sync_path(path)) {
+               logger(mesh, MESHLINK_ERROR, "Failed to sync `%s': %s", path, strerror(errno));
+               meshlink_errno = MESHLINK_ESTORAGE;
+               return false;
+       }
+
        return true;
 }
 
@@ -880,6 +901,7 @@ bool invitation_write(meshlink_handle_t *mesh, const char *conf_subdir, const ch
 
        if(!f) {
                logger(mesh, MESHLINK_ERROR, "Failed to open `%s': %s", path, strerror(errno));
+               meshlink_errno = MESHLINK_ESTORAGE;
                return false;
        }
 
@@ -889,14 +911,17 @@ bool invitation_write(meshlink_handle_t *mesh, const char *conf_subdir, const ch
                return false;
        }
 
-       if(fsync(fileno(f))) {
-               logger(mesh, MESHLINK_ERROR, "Failed to sync `%s': %s", path, strerror(errno));
-               fclose(f);
+       if(fclose(f)) {
+               logger(mesh, MESHLINK_ERROR, "Failed to close `%s': %s", path, strerror(errno));
+               meshlink_errno = MESHLINK_ESTORAGE;
                return false;
        }
 
-       if(fclose(f)) {
-               logger(mesh, MESHLINK_ERROR, "Failed to close `%s': %s", path, strerror(errno));
+       snprintf(path, sizeof(path), "%s" SLASH "%s" SLASH "invitations", mesh->confbase, conf_subdir);
+
+       if(!sync_path(path)) {
+               logger(mesh, MESHLINK_ERROR, "Failed to sync `%s': %s", path, strerror(errno));
+               meshlink_errno = MESHLINK_ESTORAGE;
                return false;
        }