/* * udev_rules.c * * Userspace devfs * * Copyright (C) 2003 Greg Kroah-Hartman * Copyright (C) 2003-2005 Kay Sievers * * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation version 2 of the License. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 675 Mass Ave, Cambridge, MA 02139, USA. * */ #include #include #include #include #include #include #include #include #include #include #include "libsysfs/sysfs/libsysfs.h" #include "list.h" #include "udev_libc_wrapper.h" #include "udev.h" #include "udev_utils.h" #include "udev_version.h" #include "logging.h" #include "udev_rules.h" #include "udev_db.h" /* compare string with pattern (supports * ? [0-9] [!A-Z]) */ static int strcmp_pattern(const char *p, const char *s) { if (s[0] == '\0') { while (p[0] == '*') p++; return (p[0] != '\0'); } switch (p[0]) { case '[': { int not = 0; p++; if (p[0] == '!') { not = 1; p++; } while ((p[0] != '\0') && (p[0] != ']')) { int match = 0; if (p[1] == '-') { if ((s[0] >= p[0]) && (s[0] <= p[2])) match = 1; p += 3; } else { match = (p[0] == s[0]); p++; } if (match ^ not) { while ((p[0] != '\0') && (p[0] != ']')) p++; if (p[0] == ']') return strcmp_pattern(p+1, s+1); } } } break; case '*': if (strcmp_pattern(p, s+1)) return strcmp_pattern(p+1, s); return 0; case '\0': if (s[0] == '\0') { return 0; } break; default: if ((p[0] == s[0]) || (p[0] == '?')) return strcmp_pattern(p+1, s+1); break; } return 1; } /* extract possible {attr} and move str behind it */ static char *get_format_attribute(char **str) { char *pos; char *attr = NULL; if (*str[0] == '{') { pos = strchr(*str, '}'); if (pos == NULL) { err("missing closing brace for format"); return NULL; } pos[0] = '\0'; attr = *str+1; *str = pos+1; dbg("attribute='%s', str='%s'", attr, *str); } return attr; } /* extract possible format length and move str behind it*/ static int get_format_len(char **str) { int num; char *tail; if (isdigit(*str[0])) { num = (int) strtoul(*str, &tail, 10); if (num > 0) { *str = tail; dbg("format length=%i", num); return num; } else { err("format parsing error '%s'", *str); } } return -1; } /** Finds the lowest positive N such that N isn't present in * $(udevroot) either as a file or a symlink. * * @param name Name to check for * @return 0 if didn't exist and N otherwise. */ static int find_free_number(struct udevice *udev, const char *name) { char devpath[PATH_SIZE]; char filename[PATH_SIZE]; int num = 0; strlcpy(filename, name, sizeof(filename)); while (1) { dbg("look for existing node '%s'", filename); if (udev_db_search_name(devpath, sizeof(devpath), filename) != 0) { dbg("free num=%d", num); return num; } num++; if (num > 1000) { info("find_free_number gone crazy (num=%d), aborted", num); return -1; } snprintf(filename, sizeof(filename), "%s%d", name, num); filename[sizeof(filename)-1] = '\0'; } } static int find_sysfs_attribute(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device, const char *name, char *value, size_t len) { struct sysfs_attribute *tmpattr; dbg("look for device attribute '%s'", name); if (class_dev) { tmpattr = sysfs_get_classdev_attr(class_dev, name); if (tmpattr) goto attr_found; } if (sysfs_device) { tmpattr = sysfs_get_device_attr(sysfs_device, name); if (tmpattr) goto attr_found; } return -1; attr_found: strlcpy(value, tmpattr->value, len); remove_trailing_char(value, '\n'); dbg("found attribute '%s'", tmpattr->path); return 0; } static void apply_format(struct udevice *udev, char *string, size_t maxsize, struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device) { char temp[PATH_SIZE]; char temp2[PATH_SIZE]; char *tail, *pos, *cpos, *attr, *rest; int len; int i; char c; unsigned int next_free_number; struct sysfs_class_device *class_dev_parent; pos = string; while (1) { pos = strchr(pos, '%'); if (pos == NULL) break; pos[0] = '\0'; tail = pos+1; len = get_format_len(&tail); c = tail[0]; strlcpy(temp, tail+1, sizeof(temp)); tail = temp; dbg("format=%c, string='%s', tail='%s'",c , string, tail); attr = get_format_attribute(&tail); switch (c) { case 'p': strlcat(string, udev->devpath, maxsize); dbg("substitute kernel name '%s'", udev->kernel_name); break; case 'b': strlcat(string, udev->bus_id, maxsize); dbg("substitute bus_id '%s'", udev->bus_id); break; case 'k': strlcat(string, udev->kernel_name, maxsize); dbg("substitute kernel name '%s'", udev->kernel_name); break; case 'n': strlcat(string, udev->kernel_number, maxsize); dbg("substitute kernel number '%s'", udev->kernel_number); break; case 'm': sprintf(temp2, "%d", minor(udev->devt)); strlcat(string, temp2, maxsize); dbg("substitute minor number '%s'", temp2); break; case 'M': sprintf(temp2, "%d", major(udev->devt)); strlcat(string, temp2, maxsize); dbg("substitute major number '%s'", temp2); break; case 'c': if (udev->program_result[0] == '\0') break; /* get part part of the result string */ i = 0; if (attr != NULL) i = strtoul(attr, &rest, 10); if (i > 0) { dbg("request part #%d of result string", i); cpos = udev->program_result; while (--i) { while (cpos[0] != '\0' && !isspace(cpos[0])) cpos++; while (isspace(cpos[0])) cpos++; } if (i > 0) { err("requested part of result string not found"); break; } strlcpy(temp2, cpos, sizeof(temp2)); /* %{2+}c copies the whole string from the second part on */ if (rest[0] != '+') { cpos = strchr(temp2, ' '); if (cpos) cpos[0] = '\0'; } strlcat(string, temp2, maxsize); dbg("substitute part of result string '%s'", temp2); } else { strlcat(string, udev->program_result, maxsize); dbg("substitute result string '%s'", udev->program_result); } break; case 's': if (attr == NULL) { dbg("missing attribute"); break; } if (find_sysfs_attribute(class_dev, sysfs_device, attr, temp2, sizeof(temp2)) != 0) { dbg("sysfs attribute '%s' not found", attr); break; } /* strip trailing whitespace of sysfs value */ i = strlen(temp2); while (i > 0 && isspace(temp2[i-1])) temp2[--i] = '\0'; replace_untrusted_chars(temp2); strlcat(string, temp2, maxsize); dbg("substitute sysfs value '%s'", temp2); break; case '%': strlcat(string, "%", maxsize); pos++; break; case 'e': next_free_number = find_free_number(udev, string); if (next_free_number > 0) { sprintf(temp2, "%d", next_free_number); strlcat(string, temp2, maxsize); } break; case 'P': if (!class_dev) break; class_dev_parent = sysfs_get_classdev_parent(class_dev); if (class_dev_parent != NULL) { struct udevice udev_parent; dbg("found parent '%s', get the node name", class_dev_parent->path); udev_init_device(&udev_parent, NULL, NULL); /* lookup the name in the udev_db with the DEVPATH of the parent */ if (udev_db_get_device(&udev_parent, &class_dev_parent->path[strlen(sysfs_path)]) == 0) { strlcat(string, udev_parent.name, maxsize); dbg("substitute parent node name'%s'", udev_parent.name); } else dbg("parent not found in database"); udev_cleanup_device(&udev_parent); } break; case 'N': if (udev->tmp_node[0] == '\0') { dbg("create temporary device node for callout"); snprintf(udev->tmp_node, sizeof(udev->tmp_node), "%s/.tmp-%u-%u", udev_root, major(udev->devt), minor(udev->devt)); udev->tmp_node[sizeof(udev->tmp_node)-1] = '\0'; udev_make_node(udev, udev->tmp_node, udev->devt, 0600, 0, 0); } strlcat(string, udev->tmp_node, maxsize); dbg("substitute temporary device node name '%s'", udev->tmp_node); break; case 'r': strlcat(string, udev_root, maxsize); dbg("substitute udev_root '%s'", udev_root); break; default: err("unknown substitution type '%%%c'", c); break; } /* truncate to specified length */ if (len > 0) pos[len] = '\0'; strlcat(string, tail, maxsize); } } static int execute_program(struct udevice *udev, const char *path, char *value, int len) { int retval; int count; int status; int fds[2]; pid_t pid; char *pos; char arg[PATH_SIZE]; char *argv[(sizeof(arg) / 2) + 1]; int i; strlcpy(arg, path, sizeof(arg)); i = 0; if (strchr(path, ' ')) { pos = arg; while (pos != NULL) { if (pos[0] == '\'') { /* don't separate if in apostrophes */ pos++; argv[i] = strsep(&pos, "\'"); while (pos && pos[0] == ' ') pos++; } else { argv[i] = strsep(&pos, " "); } dbg("arg[%i] '%s'", i, argv[i]); i++; } argv[i] = NULL; dbg("execute '%s' with parsed arguments", arg); } else { argv[0] = arg; argv[1] = udev->subsystem; argv[2] = NULL; dbg("execute '%s' with subsystem '%s' argument", arg, argv[1]); } retval = pipe(fds); if (retval != 0) { err("pipe failed"); return -1; } pid = fork(); switch(pid) { case 0: /* child dup2 write side of pipe to STDOUT */ dup2(fds[1], STDOUT_FILENO); retval = execv(arg, argv); info(KEY_PROGRAM " execution of '%s' failed", path); exit(1); case -1: err("fork of '%s' failed", path); return -1; default: /* parent reads from fds[0] */ close(fds[1]); retval = 0; i = 0; while (1) { count = read(fds[0], value + i, len - i-1); if (count < 0) { err("read failed with '%s'", strerror(errno)); retval = -1; } if (count == 0) break; i += count; if (i >= len-1) { err("result len %d too short", len); retval = -1; break; } } value[i] = '\0'; close(fds[0]); waitpid(pid, &status, 0); if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) { dbg("exec program status 0x%x", status); retval = -1; } } if (!retval) { remove_trailing_char(value, '\n'); dbg("result is '%s'", value); replace_untrusted_chars(value); } else value[0] = '\0'; return retval; } static int compare_sysfs_attribute(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device, struct key_pair *pair) { char value[VALUE_SIZE]; int i; if (find_sysfs_attribute(class_dev, sysfs_device, pair->name, value, sizeof(value)) != 0) return -1; /* strip trailing whitespace of value, if not asked to match for it */ if (!isspace(pair->value[strlen(pair->value)-1])) { i = strlen(value); while (i > 0 && isspace(value[i-1])) value[--i] = '\0'; dbg("removed %i trailing whitespace chars from '%s'", strlen(value)-i, value); } dbg("compare attribute '%s' value '%s' with '%s'", pair->name, value, pair->value); if (strcmp_pattern(pair->value, value) != 0) return -1; dbg("found matching attribute '%s' with value '%s'", pair->name, pair->value); return 0; } static int match_rule(struct udevice *udev, struct udev_rule *rule, struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device) { if (rule->kernel[0] != '\0') { dbg("check for " KEY_KERNEL " rule->kernel='%s' class_dev->name='%s'", rule->kernel, class_dev->name); if (strcmp_pattern(rule->kernel, class_dev->name) != 0) { dbg(KEY_KERNEL " is not matching"); if (rule->kernel_operation != KEY_OP_NOMATCH) goto exit; } else { dbg(KEY_KERNEL " matches"); if (rule->kernel_operation == KEY_OP_NOMATCH) goto exit; } dbg(KEY_KERNEL " key is true"); } if (rule->subsystem[0] != '\0') { dbg("check for " KEY_SUBSYSTEM " rule->subsystem='%s' class_dev->name='%s'", rule->subsystem, class_dev->name); if (strcmp_pattern(rule->subsystem, udev->subsystem) != 0) { dbg(KEY_SUBSYSTEM " is not matching"); if (rule->subsystem_operation != KEY_OP_NOMATCH) goto exit; } else { dbg(KEY_SUBSYSTEM " matches"); if (rule->subsystem_operation == KEY_OP_NOMATCH) goto exit; } dbg(KEY_SUBSYSTEM " key is true"); } if (rule->env_pair_count) { int i; dbg("check for " KEY_ENV " pairs"); for (i = 0; i < rule->env_pair_count; i++) { struct key_pair *pair; const char *value; pair = &rule->env_pair[i]; value = getenv(pair->name); if (!value) { dbg(KEY_ENV "{'%s'} is not found", pair->name); goto exit; } if (strcmp_pattern(pair->value, value) != 0) { dbg(KEY_ENV "{'%s'} is not matching", pair->name); if (pair->operation != KEY_OP_NOMATCH) goto exit; } else { dbg(KEY_ENV "{'%s'} matches", pair->name); if (pair->operation == KEY_OP_NOMATCH) goto exit; } } dbg(KEY_ENV " key is true"); } /* walk up the chain of physical devices and find a match */ while (1) { /* check for matching driver */ if (rule->driver[0] != '\0') { if (sysfs_device == NULL) { dbg("device has no sysfs_device"); goto exit; } dbg("check for " KEY_DRIVER " rule->driver='%s' sysfs_device->driver_name='%s'", rule->driver, sysfs_device->driver_name); if (strcmp_pattern(rule->driver, sysfs_device->driver_name) != 0) { dbg(KEY_DRIVER " is not matching"); if (rule->driver_operation != KEY_OP_NOMATCH) goto try_parent; } else { dbg(KEY_DRIVER " matches"); if (rule->driver_operation == KEY_OP_NOMATCH) goto try_parent; } dbg(KEY_DRIVER " key is true"); } /* check for matching bus value */ if (rule->bus[0] != '\0') { if (sysfs_device == NULL) { dbg("device has no sysfs_device"); goto exit; } dbg("check for " KEY_BUS " rule->bus='%s' sysfs_device->bus='%s'", rule->bus, sysfs_device->bus); if (strcmp_pattern(rule->bus, sysfs_device->bus) != 0) { dbg(KEY_BUS " is not matching"); if (rule->bus_operation != KEY_OP_NOMATCH) goto try_parent; } else { dbg(KEY_BUS " matches"); if (rule->bus_operation == KEY_OP_NOMATCH) goto try_parent; } dbg(KEY_BUS " key is true"); } /* check for matching bus id */ if (rule->id[0] != '\0') { if (sysfs_device == NULL) { dbg("device has no sysfs_device"); goto exit; } dbg("check " KEY_ID); if (strcmp_pattern(rule->id, sysfs_device->bus_id) != 0) { dbg(KEY_ID " is not matching"); if (rule->id_operation != KEY_OP_NOMATCH) goto try_parent; } else { dbg(KEY_ID " matches"); if (rule->id_operation == KEY_OP_NOMATCH) goto try_parent; } dbg(KEY_ID " key is true"); } /* check for matching sysfs pairs */ if (rule->sysfs_pair_count) { int i; dbg("check " KEY_SYSFS " pairs"); for (i = 0; i < rule->sysfs_pair_count; i++) { struct key_pair *pair; pair = &rule->sysfs_pair[i]; if (compare_sysfs_attribute(class_dev, sysfs_device, pair) != 0) { dbg(KEY_SYSFS "{'%s'} is not matching", pair->name); if (pair->operation != KEY_OP_NOMATCH) goto try_parent; } else { dbg(KEY_SYSFS "{'%s'} matches", pair->name); if (pair->operation == KEY_OP_NOMATCH) goto try_parent; } } dbg(KEY_SYSFS " keys are true"); } /* found matching physical device */ break; try_parent: dbg("try parent sysfs device"); sysfs_device = sysfs_get_device_parent(sysfs_device); if (sysfs_device == NULL) goto exit; dbg("look at sysfs_device->path='%s'", sysfs_device->path); dbg("look at sysfs_device->bus_id='%s'", sysfs_device->bus_id); } /* execute external program */ if (rule->program[0] != '\0') { char program[PATH_SIZE]; dbg("check " KEY_PROGRAM); strlcpy(program, rule->program, sizeof(program)); apply_format(udev, program, sizeof(program), class_dev, sysfs_device); if (execute_program(udev, program, udev->program_result, sizeof(udev->program_result)) != 0) { dbg(KEY_PROGRAM " returned nonzero"); if (rule->program_operation != KEY_OP_NOMATCH) goto exit; } else { dbg(KEY_PROGRAM " returned successful"); if (rule->program_operation == KEY_OP_NOMATCH) goto exit; } dbg(KEY_PROGRAM " key is true"); } /* check for matching result of external program */ if (rule->result[0] != '\0') { dbg("check for " KEY_RESULT " rule->result='%s', udev->program_result='%s'", rule->result, udev->program_result); if (strcmp_pattern(rule->result, udev->program_result) != 0) { dbg(KEY_RESULT " is not matching"); if (rule->result_operation != KEY_OP_NOMATCH) goto exit; } else { dbg(KEY_RESULT " matches"); if (rule->result_operation == KEY_OP_NOMATCH) goto exit; } dbg(KEY_RESULT " key is true"); } /* rule matches */ return 0; exit: return -1; } int udev_rules_get_name(struct udevice *udev, struct sysfs_class_device *class_dev) { struct sysfs_class_device *class_dev_parent; struct sysfs_device *sysfs_device = NULL; struct udev_rule *rule; dbg("class_dev->name='%s'", class_dev->name); /* Figure out where the "device"-symlink is at. For char devices this will * always be in the class_dev->path. On block devices, only the main block * device will have the device symlink in it's path. All partition devices * need to look at the symlink in its parent directory. */ class_dev_parent = sysfs_get_classdev_parent(class_dev); if (class_dev_parent != NULL) { dbg("given class device has a parent, use this instead"); sysfs_device = sysfs_get_classdev_device(class_dev_parent); } else { sysfs_device = sysfs_get_classdev_device(class_dev); } if (sysfs_device) { dbg("found devices device: path='%s', bus_id='%s', bus='%s'", sysfs_device->path, sysfs_device->bus_id, sysfs_device->bus); strlcpy(udev->bus_id, sysfs_device->bus_id, sizeof(udev->bus_id)); } dbg("udev->kernel_name='%s'", udev->kernel_name); /* look for a matching rule to apply */ list_for_each_entry(rule, &udev_rule_list, node) { dbg("process rule"); if (match_rule(udev, rule, class_dev, sysfs_device) == 0) { /* apply options */ if (rule->ignore_device) { info("configured rule in '%s[%i]' applied, '%s' is ignored", rule->config_file, rule->config_line, udev->kernel_name); return -1; } if (rule->ignore_remove) { udev->ignore_remove = 1; dbg("remove event should be ignored"); } /* apply all_partitions option only at a main block device */ if (rule->partitions && udev->type == DEV_BLOCK && udev->kernel_number[0] == '\0') { udev->partitions = rule->partitions; dbg("creation of partition nodes requested"); } /* apply permissions */ if (rule->mode != 0000) { udev->mode = rule->mode; dbg("applied mode=%#o to '%s'", udev->mode, udev->kernel_name); } if (rule->owner[0] != '\0') { strlcpy(udev->owner, rule->owner, sizeof(udev->owner)); apply_format(udev, udev->owner, sizeof(udev->owner), class_dev, sysfs_device); dbg("applied owner='%s' to '%s'", udev->owner, udev->kernel_name); } if (rule->group[0] != '\0') { strlcpy(udev->group, rule->group, sizeof(udev->group)); apply_format(udev, udev->group, sizeof(udev->group), class_dev, sysfs_device); dbg("applied group='%s' to '%s'", udev->group, udev->kernel_name); } /* collect symlinks */ if (rule->symlink[0] != '\0') { char temp[PATH_SIZE]; char *pos, *next; info("configured rule in '%s[%i]' applied, added symlink '%s'", rule->config_file, rule->config_line, rule->symlink); strlcpy(temp, rule->symlink, sizeof(temp)); apply_format(udev, temp, sizeof(temp), class_dev, sysfs_device); /* add multiple symlinks separated by spaces */ pos = temp; next = strchr(temp, ' '); while (next) { next[0] = '\0'; info("add symlink '%s'", pos); name_list_add(&udev->symlink_list, pos, 0); pos = &next[1]; next = strchr(pos, ' '); } info("add symlink '%s'", pos); name_list_add(&udev->symlink_list, pos, 0); } /* rule matches */ if (rule->name[0] != '\0') { info("configured rule in '%s[%i]' applied, '%s' becomes '%s'", rule->config_file, rule->config_line, udev->kernel_name, rule->name); strlcpy(udev->name, rule->name, sizeof(udev->name)); apply_format(udev, udev->name, sizeof(udev->name), class_dev, sysfs_device); strlcpy(udev->config_file, rule->config_file, sizeof(udev->config_file)); udev->config_line = rule->config_line; if (udev->type != DEV_NET) dbg("name, '%s' is going to have owner='%s', group='%s', mode=%#o partitions=%i", udev->name, udev->owner, udev->group, udev->mode, udev->partitions); break; } if (rule->last_rule) { dbg("last rule to be applied"); break; } } } if (udev->name[0] == '\0') { /* no rule matched, so we use the kernel name */ strlcpy(udev->name, udev->kernel_name, sizeof(udev->name)); info("no rule found, use kernel name '%s'", udev->name); } if (udev->tmp_node[0] != '\0') { dbg("removing temporary device node"); unlink_secure(udev->tmp_node); udev->tmp_node[0] = '\0'; } return 0; }