diff options
| -rw-r--r-- | util-linux/mdev.c | 193 |
1 files changed, 98 insertions, 95 deletions
diff --git a/util-linux/mdev.c b/util-linux/mdev.c index a9c1469..927adf6 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; } |