cleanup comments and coding style and rewrite the mdev.conf parser to use common busybox functions and call strdup() less often ... saves a ~few hundred bytes

1 files changed, 98 insertions, 95 deletions

diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index a9c146942..927adf66f 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -35,154 +35,146 @@ static void make_device(char *path, int delete)
         /* 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.  We
-         * also depend on path having writeable space after it. */
-
+         * also depend on path having writeable space after it.
+         */
         if (!delete) {
                 strcat(path, "/dev");
                 len = open_read_close(path, temp + 1, 64);
                 *temp++ = 0;
-                if (len < 1) return;
+                if (len < 1)
+                        return;
         }
 
         /* Determine device name, type, major and minor */
-
         device_name = bb_basename(path);
-        type = path[5]=='c' ? S_IFCHR : S_IFBLK;
-
-        /* If we have a config file, look up permissions for this device */
+        type = (path[5] == 'c' ? S_IFCHR : S_IFBLK);
 
         if (ENABLE_FEATURE_MDEV_CONF) {
-                char *conf, *pos, *end;
-                int line, fd;
+                FILE *fp;
+                char *line, *vline;
+                size_t lineno = 0;
 
-                /* mmap the config file */
-                fd = open("/etc/mdev.conf", O_RDONLY);
-                if (fd < 0)
-                        goto end_parse;
-                len = xlseek(fd, 0, SEEK_END);
-                conf = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0);
-                close(fd);
-                if (!conf)
+                /* If we have a config file, look up the user settings */
+                fp = fopen_or_warn("/etc/mdev.conf", "r");
+                if (!fp)
                         goto end_parse;
 
-                line = 0;
-                /* Loop through lines in mmaped file*/
-                for (pos=conf; pos-conf<len;) {
+                while ((vline = line = xmalloc_getline(fp)) != NULL) {
                         int field;
-                        char *end2;
 
-                        line++;
-                        /* find end of this line */
-                        for (end=pos; end-conf<len && *end!='\n'; end++)
-                                ;
+                        /* A pristine copy for command execution. */
+                        char *orig_line;
+                        if (ENABLE_FEATURE_MDEV_EXEC)
+                                orig_line = xstrdup(line);
+
+                        ++lineno;
 
                         /* Three fields: regex, uid:gid, mode */
-                        for (field=0; field < (3 + ENABLE_FEATURE_MDEV_EXEC);
-                                        field++)
-                        {
-                                /* Skip whitespace */
-                                while (pos<end && isspace(*pos)) pos++;
-                                if (pos==end || *pos=='#') break;
-                                for (end2=pos;
-                                        end2<end && !isspace(*end2) && *end2!='#'; end2++)
-                                        ;
+                        for (field = 0; field < (3 + ENABLE_FEATURE_MDEV_EXEC); ++field) {
+
+                                /* Find a non-empty field */
+                                char *val;
+                                do {
+                                        val = strtok(vline, " \t");
+                                        vline = NULL;
+                                } while (val && !*val);
+                                if (!val)
+                                        break;
 
                                 if (field == 0) {
-                                        /* Regex to match this device */
 
-                                        char *regex = xstrndup(pos, end2-pos);
+                                        /* Regex to match this device */
                                         regex_t match;
                                         regmatch_t off;
                                         int result;
 
                                         /* Is this it? */
-                                        xregcomp(&match,regex, REG_EXTENDED);
+                                        xregcomp(&match, val, REG_EXTENDED);
                                         result = regexec(&match, device_name, 1, &off, 0);
                                         regfree(&match);
-                                        free(regex);
 
                                         /* If not this device, skip rest of line */
-                                        if (result || off.rm_so
-                                                        || off.rm_eo != strlen(device_name))
-                                                break;
-                                }
-                                if (field == 1) {
-                                        /* uid:gid */
+                                        if (result || off.rm_so || off.rm_eo != strlen(device_name))
+                                                goto next_line;
 
-                                        char *s, *s2;
+                                } else if (field == 1) {
 
-                                        /* Find : */
-                                        for (s=pos; s<end2 && *s!=':'; s++)
-                                                ;
-                                        if (s == end2) break;
+                                        /* uid:gid device ownership */
+                                        struct passwd *pass;
+                                        struct group *grp;
+
+                                        char *str_uid = val;
+                                        char *str_gid = strchr(val, ':');
+                                        if (str_gid)
+                                                *str_gid = '\0', ++str_gid;
 
                                         /* Parse UID */
-                                        uid = strtoul(pos, &s2, 10);
-                                        if (s != s2) {
-                                                struct passwd *pass;
-                                                char *_unam = xstrndup(pos, s-pos);
-                                                pass = getpwnam(_unam);
-                                                free(_unam);
-                                                if (!pass) break;
+                                        pass = getpwnam(str_uid);
+                                        if (pass)
                                                 uid = pass->pw_uid;
-                                        }
-                                        s++;
+                                        else
+                                                uid = strtoul(str_uid, NULL, 10);
+
                                         /* parse GID */
-                                        gid = strtoul(s, &s2, 10);
-                                        if (end2 != s2) {
-                                                struct group *grp;
-                                                char *_grnam = xstrndup(s, end2-s);
-                                                grp = getgrnam(_grnam);
-                                                free(_grnam);
-                                                if (!grp) break;
+                                        grp = getgrnam(str_gid);
+                                        if (grp)
                                                 gid = grp->gr_gid;
-                                        }
-                                }
-                                if (field == 2) {
-                                        /* mode */
+                                        else
+                                                gid = strtoul(str_gid, NULL, 10);
 
-                                        mode = strtoul(pos, &pos, 8);
-                                        if (pos != end2) break;
-                                }
-                                if (ENABLE_FEATURE_MDEV_EXEC && field == 3) {
-                                        // Command to run
+                                } else if (field == 2) {
+
+                                        /* Mode device permissions */
+                                        mode = strtoul(val, NULL, 8);
+
+                                } else if (ENABLE_FEATURE_MDEV_EXEC && field == 3) {
+
+                                        /* Optional command to run */
                                         const char *s = "@$*";
-                                        const char *s2;
-                                        s2 = strchr(s, *pos++);
+                                        const char *s2 = strchr(s, *val);
+
                                         if (!s2) {
-                                                // Force error
+                                                /* Force error */
                                                 field = 1;
                                                 break;
                                         }
-                                        if ((s2-s+1) & (1<<delete))
-                                                command = xstrndup(pos, end-pos);
-                                }
 
-                                pos = end2;
+                                        /* Correlate the position in the "@$*" with the delete
+                                         * step so that we get the proper behavior.
+                                         */
+                                        if ((s2 - s + 1) & (1 << delete))
+                                                command = xstrdup(orig_line + (val + 1 - line));
+                                }
                         }
 
                         /* Did everything parse happily? */
+                        if (field <= 2)
+                                bb_error_msg_and_die("bad line %i", lineno);
 
-                        if (field > 2) break;
-                        if (field) bb_error_msg_and_die("bad line %d",line);
-
-                        /* Next line */
-                        pos = ++end;
+ next_line:
+                        free(line);
+                        if (ENABLE_FEATURE_MDEV_EXEC)
+                                free(orig_line);
                 }
-                munmap(conf, len);
+
+                if (ENABLE_FEATURE_CLEAN_UP)
+                        fclose(fp);
+
  end_parse:     /* nothing */ ;
         }
 
         umask(0);
         if (!delete) {
-                if (sscanf(temp, "%d:%d", &major, &minor) != 2) return;
+                if (sscanf(temp, "%d:%d", &major, &minor) != 2)
+                        return;
                 if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST)
                         bb_perror_msg_and_die("mknod %s", device_name);
 
                 if (major == root_major && minor == root_minor)
                         symlink(device_name, "root");
 
-                if (ENABLE_FEATURE_MDEV_CONF) chown(device_name, uid, gid);
+                if (ENABLE_FEATURE_MDEV_CONF)
+                        chown(device_name, uid, gid);
         }
         if (command) {
                 /* setenv will leak memory, so use putenv */
@@ -195,7 +187,8 @@ static void make_device(char *path, int delete)
                 free(s);
                 free(command);
         }
-        if (delete) unlink(device_name);
+        if (delete)
+                remove_file(device_name, FILEUTILS_FORCE);
 }
 
 /* File callback for /sys/ traversal */
@@ -296,9 +289,12 @@ int mdev_main(int argc, char **argv)
 
         xchdir("/dev");
 
-        /* Scan */
-
         if (argc == 2 && !strcmp(argv[1],"-s")) {
+
+                /* Scan:
+                 * mdev -s
+                 */
+
                 struct stat st;
 
                 xstat("/", &st);
@@ -313,9 +309,14 @@ int mdev_main(int argc, char **argv)
                         ACTION_RECURSE | ACTION_FOLLOWLINKS,
                         fileAction, dirAction, temp, 0);
 
-        /* Hotplug */
-
         } else {
+
+                /* Hotplug:
+                 * env ACTION=... DEVPATH=... mdev
+                 * ACTION can be "add" or "remove"
+                 * DEVPATH is like "/block/sda" or "/class/input/mice"
+                 */
+
                 action = getenv("ACTION");
                 env_path = getenv("DEVPATH");
                 if (!action || !env_path)
@@ -332,6 +333,8 @@ int mdev_main(int argc, char **argv)
                 }
         }
 
-        if (ENABLE_FEATURE_CLEAN_UP) RELEASE_CONFIG_BUFFER(temp);
+        if (ENABLE_FEATURE_CLEAN_UP)
+                RELEASE_CONFIG_BUFFER(temp);
+
         return 0;
 }