mdev: support $ENVVAR=regex

diff --git a/testsuite/mdev.tests b/testsuite/mdev.tests
index 388c41d529fc38634e4e8a65049612a0859082db..6d6a21d417c39b4a38354daa753fa819acf046a7 100755 (executable)
--- a/testsuite/mdev.tests
+++ b/testsuite/mdev.tests
@@ -59,6 +59,19 @@ br--r--r-- 1 2 2 8,0 sda
 " \
        "" ""
 
+# continuing to use directory structure from prev test
+rm -rf mdev.testdir/dev/*
+echo "\$MODALIAS=qw  1:1 666" >mdev.testdir/etc/mdev.conf
+echo "\$MODALIAS=qw. 2:2 444" >>mdev.testdir/etc/mdev.conf
+echo "\$MODALIAS=qw. 3:3 400" >>mdev.testdir/etc/mdev.conf
+testing "mdev \$ENVVAR=regex match" \
+       "env - PATH=$PATH ACTION=add DEVPATH=/block/sda MODALIAS=qwe chroot mdev.testdir /mdev 2>&1;
+       ls -ln mdev.testdir/dev | $FILTER_LS" \
+"\
+br--r--r-- 1 2 2 8,0 sda
+" \
+       "" ""
+
 # continuing to use directory structure from prev test
 rm -rf mdev.testdir/dev/*
 echo "sda 0:0 444 >disk/scsiA" >mdev.testdir/etc/mdev.conf

diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index a3275f881c8a0c17ff024bbb6e4e4f41f3cb8641..ea1edcc40dd94c53130428bce481600a1f3e4920 100644 (file)
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -89,15 +89,11 @@ static char *build_alias(char *alias, const char *device_name)
 /* NB: "mdev -s" may call us many times, do not leak memory/fds! */
 static void make_device(char *path, int delete)
 {
-       const char *device_name;
+       char *device_name;
        int major, minor, type, len;
        int mode;
-       char *dev_maj_min = path + strlen(path);
        parser_t *parser;
 
-       /* Force the configuration file settings exactly. */
-       umask(0);
-
        /* Try to read major/minor string.  Note that the kernel puts \n after
         * the data, so we don't need to worry about null terminating the string
         * because sscanf() will stop at the first nondigit, which \n is.
@@ -105,21 +101,23 @@ static void make_device(char *path, int delete)
         */
        major = -1;
        if (!delete) {
+               char *dev_maj_min = path + strlen(path);
+
                strcpy(dev_maj_min, "/dev");
                len = open_read_close(path, dev_maj_min + 1, 64);
-               *dev_maj_min++ = '\0';
+               *dev_maj_min = '\0';
                if (len < 1) {
                        if (!ENABLE_FEATURE_MDEV_EXEC)
                                return;
-                       /* no "dev" file, so just try to run script */
-                       *dev_maj_min = '\0';
-               } else if (sscanf(dev_maj_min, "%u:%u", &major, &minor) != 2) {
+                       /* no "dev" file, but we can still run scripts
+                        * based on device name */
+               } else if (sscanf(++dev_maj_min, "%u:%u", &major, &minor) != 2) {
                        major = -1;
                }
        }
 
        /* Determine device name, type, major and minor */
-       device_name = bb_basename(path);
+       device_name = (char*) bb_basename(path);
        /* http://kernel.org/doc/pending/hotplug.txt says that only
         * "/sys/block/..." is for block devices. "/sys/bus" etc is not.
         * But since 2.6.25 block devices are also in /sys/class/block,
@@ -139,9 +137,7 @@ static void make_device(char *path, int delete)
                parser = config_open2("/etc/mdev.conf", fopen_for_read);
 
        do {
-               regmatch_t off[1 + 9 * ENABLE_FEATURE_MDEV_RENAME_REGEXP];
                int keep_matching;
-               char *val, *name;
                struct bb_uidgid_t ugid;
                char *tokens[4];
                char *command = NULL;
@@ -156,19 +152,22 @@ static void make_device(char *path, int delete)
                if (ENABLE_FEATURE_MDEV_CONF
                 && config_read(parser, tokens, 4, 3, "# \t", PARSE_NORMAL)
                ) {
+                       char *val;
+                       char *str_to_match;
+                       regmatch_t off[1 + 9 * ENABLE_FEATURE_MDEV_RENAME_REGEXP];
+
                        val = tokens[0];
                        keep_matching = ('-' == val[0]);
                        val += keep_matching; /* swallow leading dash */
 
                        /* Match against either "subsystem/device_name"
                         * or "device_name" alone */
-                       name = strchr(val, '/') ? path : (char *) device_name;
+                       str_to_match = strchr(val, '/') ? path : device_name;
 
                        /* Fields: regex uid:gid mode [alias] [cmd] */
 
-                       /* 1st field: @<numeric maj,min>... */
                        if (val[0] == '@') {
-                               /* @major,minor[-last] */
+                               /* @major,minor[-minor2] */
                                /* (useful when name is ambiguous:
                                 * "/sys/class/usb/lp0" and
                                 * "/sys/class/printer/lp0") */
@@ -182,15 +181,29 @@ static void make_device(char *path, int delete)
                                ) {
                                        continue; /* this line doesn't match */
                                }
-                       } else { /* ... or regex to match device name */
+                               goto line_matches;
+                       }
+                       if (val[0] == '$') {
+                               /* regex to match an environment variable */
+                               char *eq = strchr(++val, '=');
+                               if (!eq)
+                                       continue;
+                               *eq = '\0';
+                               str_to_match = getenv(val);
+                               if (!str_to_match)
+                                       continue;
+                               str_to_match -= strlen(val) + 1;
+                               *eq = '=';
+                       }
+                       /* else: regex to match [subsystem/]device_name */
+
+                       {
                                regex_t match;
                                int result;
 
-                               /* Is this it? */
                                xregcomp(&match, val, REG_EXTENDED);
-                               result = regexec(&match, name, ARRAY_SIZE(off), off, 0);
+                               result = regexec(&match, str_to_match, ARRAY_SIZE(off), off, 0);
                                regfree(&match);
-
                                //bb_error_msg("matches:");
                                //for (int i = 0; i < ARRAY_SIZE(off); i++) {
                                //      if (off[i].rm_so < 0) continue;
@@ -199,17 +212,17 @@ static void make_device(char *path, int delete)
                                //              device_name + off[i].rm_so);
                                //}
 
-                               /* If not this device, skip rest of line */
+                               /* If no match, skip rest of line */
                                /* (regexec returns whole pattern as "range" 0) */
                                if (result || off[0].rm_so
-                                || ((int)off[0].rm_eo != (int)strlen(name))
+                                || ((int)off[0].rm_eo != (int)strlen(str_to_match))
                                ) {
                                        continue; /* this line doesn't match */
                                }
                        }
-
-                       /* This line matches: stop parsing the file after parsing
-                        * the rest of fields unless keep_matching == 1 */
+ line_matches:
+                       /* This line matches. Stop parsing after parsing
+                        * the rest the line unless keep_matching == 1 */
 
                        /* 2nd field: uid:gid - device ownership */
                        parse_chown_usergroup_or_die(&ugid, tokens[1]);
@@ -243,7 +256,7 @@ static void make_device(char *path, int delete)
                                                        if (*s++ == '%')
                                                                n++;
 
-                                               p = alias = xzalloc(strlen(a) + n * strlen(name));
+                                               p = alias = xzalloc(strlen(a) + n * strlen(str_to_match));
                                                s = a + 1;
                                                while (*s) {
                                                        *p = *s;
@@ -251,7 +264,7 @@ static void make_device(char *path, int delete)
                                                                i = (s[1] - '0');
                                                                if (i <= 9 && off[i].rm_so >= 0) {
                                                                        n = off[i].rm_eo - off[i].rm_so;
-                                                                       strncpy(p, name + off[i].rm_so, n);
+                                                                       strncpy(p, str_to_match + off[i].rm_so, n);
                                                                        p += n - 1;
                                                                        s++;
                                                                }
@@ -447,9 +460,11 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
 
        /* We can be called as hotplug helper */
        /* Kernel cannot provide suitable stdio fds for us, do it ourself */
-
        bb_sanitize_stdio();
 
+       /* Force the configuration file settings exactly */
+       umask(0);
+
        xchdir("/dev");
 
        if (argv[1] && strcmp(argv[1], "-s") == 0) {