cleanup comments and coding style and rewrite the mdev.conf parser to use common...
authorMike Frysinger <vapier@gentoo.org>
Mon, 19 Nov 2007 09:04:22 +0000 (09:04 -0000)
committerMike Frysinger <vapier@gentoo.org>
Mon, 19 Nov 2007 09:04:22 +0000 (09:04 -0000)
util-linux/mdev.c

index a9c146942166d8e40de9d2daf9b424aff6511934..927adf66fa67dad35c5238b9839431ef531d490e 100644 (file)
@@ -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;
 }