From 1bb734a44952a51285057409ba7b1c3e7a162cea Mon Sep 17 00:00:00 2001

From: Michal Sekletar <msekleta@redhat.com>

Date: Thu, 2 Aug 2018 13:16:49 +0200

Subject: [PATCH] Revert "udev: remove WAIT_FOR key"

This reverts commit f2b8052fb648b788936dd3e85be6a9aca90fbb2f.

Resolves: #1523213

---

 man/udev.xml              |  9 +++++++

 src/udev/udev-rules.c     | 50 +++++++++++++++++++++++++++++++++++++++

 test/rule-syntax-check.py |  2 +-

 3 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/man/udev.xml b/man/udev.xml

index 15e6d8eae..bdf901a8f 100644

--- a/man/udev.xml

+++ b/man/udev.xml

@@ -515,6 +515,15 @@

           </listitem>

         </varlistentry>

+        <varlistentry>

+          <term><varname>WAIT_FOR</varname></term>

+          <listitem>

+            <para>Wait for a file to become available or until a timeout of

+            10 seconds expires. The path is relative to the sysfs device;

+            if no path is specified, this waits for an attribute to appear.</para>

+          </listitem>

+        </varlistentry>

+

         <varlistentry>

           <term><varname>OPTIONS</varname></term>

           <listitem>

diff --git a/src/udev/udev-rules.c b/src/udev/udev-rules.c

index f02939588..58af863f3 100644

--- a/src/udev/udev-rules.c

+++ b/src/udev/udev-rules.c

@@ -676,6 +676,41 @@ static int import_parent_into_properties(struct udev_device *dev, const char *fi

         return 0;

 }

+#define WAIT_LOOP_PER_SECOND                50

+static int wait_for_file(struct udev_device *dev, const char *file, int timeout) {

+        char filepath[UTIL_PATH_SIZE];

+        char devicepath[UTIL_PATH_SIZE];

+        struct stat stats;

+        int loop = timeout * WAIT_LOOP_PER_SECOND;

+

+        /* a relative path is a device attribute */

+        devicepath[0] = '\0';

+        if (file[0] != '/') {

+                strscpyl(devicepath, sizeof(devicepath), udev_device_get_syspath(dev), NULL);

+                strscpyl(filepath, sizeof(filepath), devicepath, "/", file, NULL);

+                file = filepath;

+        }

+

+        while (--loop) {

+                const struct timespec duration = { 0, 1000 * 1000 * 1000 / WAIT_LOOP_PER_SECOND };

+

+                /* lookup file */

+                if (stat(file, &stats) == 0) {

+                        log_debug("file '%s' appeared after %i loops", file, (timeout * WAIT_LOOP_PER_SECOND) - loop-1);

+                        return 0;

+                }

+                /* make sure, the device did not disappear in the meantime */

+                if (devicepath[0] != '\0' && stat(devicepath, &stats) != 0) {

+                        log_debug("device disappeared while waiting for '%s'", file);

+                        return -2;

+                }

+                log_debug("wait for '%s' for %i mseconds", file, 1000 / WAIT_LOOP_PER_SECOND);

+                nanosleep(&duration, NULL);

+        }

+        log_debug("waiting for '%s' failed", file);

+        return -1;

+}

+

 static void attr_subst_subdir(char *attr, size_t len) {

         const char *pos, *tail, *path;

         _cleanup_closedir_ DIR *dir = NULL;

@@ -1284,7 +1319,12 @@ static void add_rule(struct udev_rules *rules, char *line,

                                 rule_add_key(&rule_tmp, TK_A_RUN_PROGRAM, op, value, &cmd);

                         } else

                                 LOG_RULE_ERROR("ignoring unknown %s{} type '%s'", "RUN", attr);

+                } else if (streq(key, "WAIT_FOR") || streq(key, "WAIT_FOR_SYSFS")) {

+                        if (op == OP_REMOVE)

+                                LOG_AND_RETURN("invalid %s operation", key);

+                        rule_add_key(&rule_tmp, TK_M_WAITFOR, 0, value, NULL);

+                        continue;

                 } else if (streq(key, "LABEL")) {

                         if (op == OP_REMOVE)

                                 LOG_AND_RETURN("invalid %s operation", key);

@@ -1838,6 +1878,16 @@ void udev_rules_apply_to_event(struct udev_rules *rules,

                         if (match_key(rules, cur, udev_device_get_driver(event->dev)) != 0)

                                 goto nomatch;

                         break;

+                case TK_M_WAITFOR: {

+                        char filename[UTIL_PATH_SIZE];

+                        int found;

+

+                        udev_event_apply_format(event, rules_str(rules, cur->key.value_off), filename, sizeof(filename), false);

+                        found = (wait_for_file(event->dev, filename, 10) == 0);

+                        if (!found && (cur->key.op != OP_NOMATCH))

+                                goto nomatch;

+                        break;

+                }

                 case TK_M_ATTR:

                         if (match_attr(rules, event->dev, event, cur) != 0)

                                 goto nomatch;

diff --git a/test/rule-syntax-check.py b/test/rule-syntax-check.py

index dfb06d9ed..706d93632 100755

--- a/test/rule-syntax-check.py

+++ b/test/rule-syntax-check.py

@@ -18,7 +18,7 @@ if not rules_files:

 quoted_string_re = r'"(?:[^\\"]|\\.)*"'

 no_args_tests = re.compile(r'(ACTION|DEVPATH|KERNELS?|NAME|SYMLINK|SUBSYSTEMS?|DRIVERS?|TAG|PROGRAM|RESULT|TEST)\s*(?:=|!)=\s*' + quoted_string_re + '$')

 args_tests = re.compile(r'(ATTRS?|ENV|TEST){([a-zA-Z0-9/_.*%-]+)}\s*(?:=|!)=\s*' + quoted_string_re + '$')

-no_args_assign = re.compile(r'(NAME|SYMLINK|OWNER|GROUP|MODE|TAG|RUN|LABEL|GOTO|OPTIONS|IMPORT)\s*(?:\+=|:=|=)\s*' + quoted_string_re + '$')

+no_args_assign = re.compile(r'(NAME|SYMLINK|OWNER|GROUP|MODE|TAG|RUN|LABEL|GOTO|WAIT_FOR|OPTIONS|IMPORT)\s*(?:\+=|:=|=)\s*' + quoted_string_re + '$')

 args_assign = re.compile(r'(ATTR|ENV|IMPORT|RUN){([a-zA-Z0-9/_.*%-]+)}\s*(=|\+=)\s*' + quoted_string_re + '$')

 # Find comma-separated groups, but allow commas that are inside quoted strings.

 # Using quoted_string_re + '?' so that strings missing the last double quote