udev-event: add replace_whitespace param to udev_event_apply_format

If replace_whitespace is true, each substitution value has all its
whitespace removed/replaced by util_replace_whitespace (except the
SUBST_RESULT substitution - $result{} or %c{} - which handles spaces
itself as field separators).  All existing callers are updated to
pass false, so no functional change is made by this patch.

This is needed so the SYMLINK assignment can replace any spaces
introduced through variable substitution, becuase the SYMLINK value is
a space-separated list of symlinks to create.  Any variables that
contain spaces will thus unexpectedly change the symlink value from
a single symlink to multiple incorrectly-named symlinks.

This is used in the next patch, which enables the whitespace
replacement for SYMLINK variable substitution.

1 files changed, 35 insertions, 4 deletions

diff --git a/src/udev/udev-event.c b/src/udev/udev-event.c
index 304a28777b..be7c7367ff 100644
--- a/src/udev/udev-event.c
+++ b/src/udev/udev-event.c
@@ -73,7 +73,9 @@ void udev_event_unref(struct udev_event *event) {
         free(event);
 }
 
-size_t udev_event_apply_format(struct udev_event *event, const char *src, char *dest, size_t size) {
+size_t udev_event_apply_format(struct udev_event *event,
+                               const char *src, char *dest, size_t size,
+                               bool replace_whitespace) {
         struct udev_device *dev = event->dev;
         enum subst_type {
                 SUBST_UNKNOWN,
@@ -130,8 +132,10 @@ size_t udev_event_apply_format(struct udev_event *event, const char *src, char *
 
         for (;;) {
                 enum subst_type type = SUBST_UNKNOWN;
-                char attrbuf[UTIL_PATH_SIZE];
-                char *attr = NULL;
+                char attrbuf[UTIL_PATH_SIZE], sbuf[UTIL_PATH_SIZE];
+                char *attr = NULL, *_s;
+                size_t _l;
+                bool replws = replace_whitespace;
 
                 while (from[0] != '\0') {
                         if (from[0] == '$') {
@@ -200,6 +204,19 @@ subst:
                         attr = NULL;
                 }
 
+                /* result subst handles space as field separator */
+                if (type == SUBST_RESULT)
+                        replws = false;
+
+                if (replws) {
+                        /* store dest string ptr and remaining len */
+                        _s = s;
+                        _l = l;
+                        /* temporarily use sbuf */
+                        s = &sbuf;
+                        l = UTIL_PATH_SIZE;
+                }
+
                 switch (type) {
                 case SUBST_DEVPATH:
                         l = strpcpy(&s, l, udev_device_get_devpath(dev));
@@ -380,6 +397,20 @@ subst:
                         log_error("unknown substitution type=%i", type);
                         break;
                 }
+
+                /* replace whitespace in sbuf and copy to dest */
+                if (replws) {
+                        size_t tmplen = UTIL_PATH_SIZE - l;
+
+                        /* restore s and l to dest string values */
+                        s = _s;
+                        l = _l;
+
+                        /* copy ws-replaced value to s */
+                        tmplen = util_replace_whitespace(sbuf, s, MIN(tmplen, l));
+                        l -= tmplen;
+                        s += tmplen;
+                }
         }
 
 out:
@@ -927,7 +958,7 @@ void udev_event_execute_run(struct udev_event *event, usec_t timeout_usec, usec_
                 const char *cmd = udev_list_entry_get_name(list_entry);
                 enum udev_builtin_cmd builtin_cmd = udev_list_entry_get_num(list_entry);
 
-                udev_event_apply_format(event, cmd, command, sizeof(command));
+                udev_event_apply_format(event, cmd, command, sizeof(command), false);
 
                 if (builtin_cmd < UDEV_BUILTIN_MAX)
                         udev_builtin_run(event->dev, builtin_cmd, command, false);