util: rework cunescape(), improve error handling

Change cunescape() to return a normal error code, so that we can
distuingish OOM errors from parse errors.

This also adds a flags parameter to control whether "relaxed" or normal
parsing shall be done. If set no parse failures are generated, and the
only reason why cunescape() can fail is OOM.

5 files changed, 51 insertions, 55 deletions

diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index 07384d3668..e61418db50 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -507,16 +507,17 @@ int config_parse_exec_oom_score_adjust(const char* unit,
         return 0;
 }
 
-int config_parse_exec(const char *unit,
-                      const char *filename,
-                      unsigned line,
-                      const char *section,
-                      unsigned section_line,
-                      const char *lvalue,
-                      int ltype,
-                      const char *rvalue,
-                      void *data,
-                      void *userdata) {
+int config_parse_exec(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
 
         ExecCommand **e = data, *nce;
         char *path, **n;
@@ -568,15 +569,13 @@ int config_parse_exec(const char *unit,
                                                 word ++;
                                         }
                                 }
-                        } else
-                                if (strneq(word, ";", MAX(l, 1U)))
+                        } else if (strneq(word, ";", MAX(l, 1U)))
                                         goto found;
 
                         k++;
                 }
                 if (!isempty(state)) {
-                        log_syntax(unit, LOG_ERR, filename, line, EINVAL,
-                                   "Trailing garbage, ignoring.");
+                        log_syntax(unit, LOG_ERR, filename, line, EINVAL, "Trailing garbage, ignoring.");
                         return 0;
                 }
 
@@ -605,9 +604,10 @@ int config_parse_exec(const char *unit,
                         else
                                 skip = strneq(word, "\\;", MAX(l, 1U));
 
-                        c = cunescape_length(word + skip, l - skip);
-                        if (!c) {
-                                r = log_oom();
+                        r = cunescape_length(word + skip, l - skip, 0, &c);
+                        if (r < 0) {
+                                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to unescape command line, ignoring: %s", rvalue);
+                                r = 0;
                                 goto fail;
                         }
 
@@ -637,8 +637,7 @@ int config_parse_exec(const char *unit,
                 else
                         goto ok;
 
-                log_syntax(unit, LOG_ERR, filename, line, EINVAL,
-                           "%s, ignoring: %s", reason, rvalue);
+                log_syntax(unit, LOG_ERR, filename, line, EINVAL, "%s, ignoring: %s", reason, rvalue);
                 r = 0;
                 goto fail;
 
@@ -1976,8 +1975,7 @@ int config_parse_environ(const char *unit,
         if (u) {
                 r = unit_full_printf(u, rvalue, &k);
                 if (r < 0)
-                        log_syntax(unit, LOG_ERR, filename, line, -r,
-                                   "Failed to resolve specifiers, ignoring: %s", rvalue);
+                        log_syntax(unit, LOG_ERR, filename, line, -r, "Failed to resolve specifiers, ignoring: %s", rvalue);
         }
 
         if (!k)
@@ -1989,13 +1987,14 @@ int config_parse_environ(const char *unit,
                 _cleanup_free_ char *n;
                 char **x;
 
-                n = cunescape_length(word, l);
-                if (!n)
-                        return log_oom();
+                r = cunescape_length(word, l, 0, &n);
+                if (r < 0) {
+                        log_syntax(unit, LOG_ERR, filename, line, r, "Couldn't unescape assignment, ignoring: %s", rvalue);
+                        continue;
+                }
 
                 if (!env_assignment_is_valid(n)) {
-                        log_syntax(unit, LOG_ERR, filename, line, EINVAL,
-                                   "Invalid environment assignment, ignoring: %s", rvalue);
+                        log_syntax(unit, LOG_ERR, filename, line, EINVAL, "Invalid environment assignment, ignoring: %s", rvalue);
                         continue;
                 }
 
diff --git a/src/core/manager.c b/src/core/manager.c
index 73417ab1a8..1c912fcdf7 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -2426,11 +2426,9 @@ int manager_deserialize(Manager *m, FILE *f, FDSet *fds) {
                         _cleanup_free_ char *uce = NULL;
                         char **e;
 
-                        uce = cunescape(l+4);
-                        if (!uce) {
-                                r = -ENOMEM;
+                        r = cunescape(l + 4, UNESCAPE_RELAX, &uce);
+                        if (r < 0)
                                 goto finish;
-                        }
 
                         e = strv_env_set(m->environment, uce);
                         if (!e) {
diff --git a/src/core/mount.c b/src/core/mount.c
index 53594cd40b..c4aa810d05 100644
--- a/src/core/mount.c
+++ b/src/core/mount.c
@@ -1579,7 +1579,7 @@ static int mount_load_proc_self_mountinfo(Manager *m, bool set_flags) {
         r = 0;
         for (;;) {
                 const char *device, *path, *options, *fstype;
-                _cleanup_free_ const char *d = NULL, *p = NULL;
+                _cleanup_free_ char *d = NULL, *p = NULL;
                 struct libmnt_fs *fs;
                 int k;
 
@@ -1594,12 +1594,10 @@ static int mount_load_proc_self_mountinfo(Manager *m, bool set_flags) {
                 options = mnt_fs_get_options(fs);
                 fstype = mnt_fs_get_fstype(fs);
 
-                d = cunescape(device);
-                if (!d)
+                if (cunescape(device, UNESCAPE_RELAX, &d) < 0)
                         return log_oom();
 
-                p = cunescape(path);
-                if (!p)
+                if (cunescape(path, UNESCAPE_RELAX, &p) < 0)
                         return log_oom();
 
                 (void) device_found_node(m, d, true, DEVICE_FOUND_MOUNT, set_flags);
diff --git a/src/core/swap.c b/src/core/swap.c
index 6b1bdb5c1e..53f127484f 100644
--- a/src/core/swap.c
+++ b/src/core/swap.c
@@ -1099,8 +1099,7 @@ static int swap_load_proc_swaps(Manager *m, bool set_flags) {
                         continue;
                 }
 
-                d = cunescape(dev);
-                if (!d)
+                if (cunescape(dev, UNESCAPE_RELAX, &d) < 0)
                         return log_oom();
 
                 device_found_node(m, d, true, DEVICE_FOUND_SWAP, set_flags);
diff --git a/src/core/umount.c b/src/core/umount.c
index ceee70fbea..bee267a5ad 100644
--- a/src/core/umount.c
+++ b/src/core/umount.c
@@ -62,6 +62,7 @@ static void mount_points_list_free(MountPoint **head) {
 static int mount_points_list_get(MountPoint **head) {
         _cleanup_fclose_ FILE *proc_self_mountinfo = NULL;
         unsigned int i;
+        int r;
 
         assert(head);
 
@@ -97,9 +98,9 @@ static int mount_points_list_get(MountPoint **head) {
                         continue;
                 }
 
-                p = cunescape(path);
-                if (!p)
-                        return -ENOMEM;
+                r = cunescape(path, UNESCAPE_RELAX, &p);
+                if (r < 0)
+                        return r;
 
                 /* Ignore mount points we can't unmount because they
                  * are API or because we are keeping them open (like
@@ -133,10 +134,12 @@ static int mount_points_list_get(MountPoint **head) {
 static int swap_list_get(MountPoint **head) {
         _cleanup_fclose_ FILE *proc_swaps = NULL;
         unsigned int i;
+        int r;
 
         assert(head);
 
-        if (!(proc_swaps = fopen("/proc/swaps", "re")))
+        proc_swaps = fopen("/proc/swaps", "re");
+        if (!proc_swaps)
                 return (errno == ENOENT) ? 0 : -errno;
 
         (void) fscanf(proc_swaps, "%*s %*s %*s %*s %*s\n");
@@ -146,19 +149,19 @@ static int swap_list_get(MountPoint **head) {
                 char *dev = NULL, *d;
                 int k;
 
-                if ((k = fscanf(proc_swaps,
-                                "%ms " /* device/file */
-                                "%*s " /* type of swap */
-                                "%*s " /* swap size */
-                                "%*s " /* used */
-                                "%*s\n", /* priority */
-                                &dev)) != 1) {
+                k = fscanf(proc_swaps,
+                           "%ms " /* device/file */
+                           "%*s " /* type of swap */
+                           "%*s " /* swap size */
+                           "%*s " /* used */
+                           "%*s\n", /* priority */
+                           &dev);
 
+                if (k != 1) {
                         if (k == EOF)
                                 break;
 
                         log_warning("Failed to parse /proc/swaps:%u.", i);
-
                         free(dev);
                         continue;
                 }
@@ -168,14 +171,13 @@ static int swap_list_get(MountPoint **head) {
                         continue;
                 }
 
-                d = cunescape(dev);
+                r = cunescape(dev, UNESCAPE_RELAX, &d);
                 free(dev);
+                if (r < 0)
+                        return r;
 
-                if (!d) {
-                        return -ENOMEM;
-                }
-
-                if (!(swap = new0(MountPoint, 1))) {
+                swap = new0(MountPoint, 1);
+                if (!swap) {
                         free(d);
                         return -ENOMEM;
                 }