From 8e3ba3772cadf6a8292b0da533062dd4d377af67 Mon Sep 17 00:00:00 2001 From: David Herrmann Date: Thu, 11 Sep 2014 13:25:21 +0200 Subject: udev: allow removing tags via TAG-="foobar" This extends the udev parser to support OP_REMOVE (-=) and adds support for TAG-= to remove previously set tags. We don't fail if the tag didn't exist. This is pretty handy if we ship default rules for seat-assignments and users want to exclude specific devices from that. They can easily add rules that drop any automatically added "seat" tags again. --- src/libudev/libudev-device.c | 21 +++++++++++- src/libudev/libudev-private.h | 1 + src/udev/udev-rules.c | 78 +++++++++++++++++++++++++++++++++++++++++-- 3 files changed, 96 insertions(+), 4 deletions(-) (limited to 'src') diff --git a/src/libudev/libudev-device.c b/src/libudev/libudev-device.c index f26a4c44b5..d61a2ad8f4 100644 --- a/src/libudev/libudev-device.c +++ b/src/libudev/libudev-device.c @@ -1732,9 +1732,14 @@ void udev_device_set_is_initialized(struct udev_device *udev_device) udev_device->is_initialized = true; } +static bool is_valid_tag(const char *tag) +{ + return !strchr(tag, ':') && !strchr(tag, ' '); +} + int udev_device_add_tag(struct udev_device *udev_device, const char *tag) { - if (strchr(tag, ':') != NULL || strchr(tag, ' ') != NULL) + if (!is_valid_tag(tag)) return -EINVAL; udev_device->tags_uptodate = false; if (udev_list_entry_add(&udev_device->tags_list, tag, NULL) != NULL) @@ -1742,6 +1747,20 @@ int udev_device_add_tag(struct udev_device *udev_device, const char *tag) return -ENOMEM; } +void udev_device_remove_tag(struct udev_device *udev_device, const char *tag) +{ + struct udev_list_entry *e; + + if (!is_valid_tag(tag)) + return; + e = udev_list_get_entry(&udev_device->tags_list); + e = udev_list_entry_get_by_name(e, tag); + if (e) { + udev_device->tags_uptodate = false; + udev_list_entry_delete(e); + } +} + void udev_device_cleanup_tags_list(struct udev_device *udev_device) { udev_device->tags_uptodate = false; diff --git a/src/libudev/libudev-private.h b/src/libudev/libudev-private.h index cd1c1fb8b3..35ea7ba44c 100644 --- a/src/libudev/libudev-private.h +++ b/src/libudev/libudev-private.h @@ -73,6 +73,7 @@ const char *udev_device_get_devpath_old(struct udev_device *udev_device); const char *udev_device_get_id_filename(struct udev_device *udev_device); void udev_device_set_is_initialized(struct udev_device *udev_device); int udev_device_add_tag(struct udev_device *udev_device, const char *tag); +void udev_device_remove_tag(struct udev_device *udev_device, const char *tag); void udev_device_cleanup_tags_list(struct udev_device *udev_device); usec_t udev_device_get_usec_initialized(struct udev_device *udev_device); void udev_device_set_usec_initialized(struct udev_device *udev_device, usec_t usec_initialized); diff --git a/src/udev/udev-rules.c b/src/udev/udev-rules.c index 6de7511c7d..9514dde751 100644 --- a/src/udev/udev-rules.c +++ b/src/udev/udev-rules.c @@ -82,7 +82,7 @@ static unsigned int rules_add_string(struct udev_rules *rules, const char *s) { return strbuf_add_string(rules->strbuf, s, strlen(s)); } -/* KEY=="", KEY!="", KEY+="", KEY="", KEY:="" */ +/* KEY=="", KEY!="", KEY+="", KEY-="", KEY="", KEY:="" */ enum operation_type { OP_UNSET, @@ -91,6 +91,7 @@ enum operation_type { OP_MATCH_MAX, OP_ADD, + OP_REMOVE, OP_ASSIGN, OP_ASSIGN_FINAL, }; @@ -224,6 +225,7 @@ static const char *operation_str(enum operation_type type) { [OP_MATCH_MAX] = "MATCH_MAX", [OP_ADD] = "add", + [OP_REMOVE] = "remove", [OP_ASSIGN] = "assign", [OP_ASSIGN_FINAL] = "assign-final", } ; @@ -761,7 +763,7 @@ static int get_key(struct udev *udev, char **line, char **key, enum operation_ty break; if (linepos[0] == '=') break; - if ((linepos[0] == '+') || (linepos[0] == '!') || (linepos[0] == ':')) + if ((linepos[0] == '+') || (linepos[0] == '-') || (linepos[0] == '!') || (linepos[0] == ':')) if (linepos[1] == '=') break; } @@ -785,6 +787,9 @@ static int get_key(struct udev *udev, char **line, char **key, enum operation_ty } else if (linepos[0] == '+' && linepos[1] == '=') { *op = OP_ADD; linepos += 2; + } else if (linepos[0] == '-' && linepos[1] == '=') { + *op = OP_REMOVE; + linepos += 2; } else if (linepos[0] == '=') { *op = OP_ASSIGN; linepos++; @@ -1121,6 +1126,10 @@ static int add_rule(struct udev_rules *rules, char *line, log_error("error parsing ATTR attribute"); goto invalid; } + if (op == OP_REMOVE) { + log_error("invalid ATTR operation"); + goto invalid; + } if (op < OP_MATCH_MAX) { rule_add_key(&rule_tmp, TK_M_ATTR, op, value, attr); } else { @@ -1135,6 +1144,10 @@ static int add_rule(struct udev_rules *rules, char *line, log_error("error parsing SECLABEL attribute"); goto invalid; } + if (op == OP_REMOVE) { + log_error("invalid SECLABEL operation"); + goto invalid; + } rule_add_key(&rule_tmp, TK_A_SECLABEL, op, value, attr); continue; @@ -1202,6 +1215,10 @@ static int add_rule(struct udev_rules *rules, char *line, log_error("error parsing ENV attribute"); goto invalid; } + if (op == OP_REMOVE) { + log_error("invalid ENV operation"); + goto invalid; + } if (op < OP_MATCH_MAX) { if (rule_add_key(&rule_tmp, TK_M_ENV, op, value, attr) != 0) goto invalid; @@ -1242,6 +1259,10 @@ static int add_rule(struct udev_rules *rules, char *line, } if (streq(key, "PROGRAM")) { + if (op == OP_REMOVE) { + log_error("invalid PROGRAM operation"); + goto invalid; + } rule_add_key(&rule_tmp, TK_M_PROGRAM, op, value, NULL); continue; } @@ -1261,6 +1282,10 @@ static int add_rule(struct udev_rules *rules, char *line, log_error("IMPORT{} type missing, ignoring IMPORT %s:%u", filename, lineno); continue; } + if (op == OP_REMOVE) { + log_error("invalid IMPORT operation"); + goto invalid; + } if (streq(attr, "program")) { /* find known built-in command */ if (value[0] != '/') { @@ -1316,6 +1341,10 @@ static int add_rule(struct udev_rules *rules, char *line, attr = get_key_attribute(rules->udev, key + strlen("RUN")); if (attr == NULL) attr = "program"; + if (op == OP_REMOVE) { + log_error("invalid RUN operation"); + goto invalid; + } if (streq(attr, "builtin")) { enum udev_builtin_cmd cmd = udev_builtin_lookup(value); @@ -1336,21 +1365,37 @@ static int add_rule(struct udev_rules *rules, char *line, } if (streq(key, "WAIT_FOR") || streq(key, "WAIT_FOR_SYSFS")) { + if (op == OP_REMOVE) { + log_error("invalid WAIT_FOR/WAIT_FOR_SYSFS operation"); + goto invalid; + } rule_add_key(&rule_tmp, TK_M_WAITFOR, 0, value, NULL); continue; } if (streq(key, "LABEL")) { + if (op == OP_REMOVE) { + log_error("invalid LABEL operation"); + goto invalid; + } rule_tmp.rule.rule.label_off = rules_add_string(rules, value); continue; } if (streq(key, "GOTO")) { + if (op == OP_REMOVE) { + log_error("invalid GOTO operation"); + goto invalid; + } rule_add_key(&rule_tmp, TK_A_GOTO, 0, value, NULL); continue; } if (startswith(key, "NAME")) { + if (op == OP_REMOVE) { + log_error("invalid NAME operation"); + goto invalid; + } if (op < OP_MATCH_MAX) { rule_add_key(&rule_tmp, TK_M_NAME, op, value, NULL); } else { @@ -1371,6 +1416,10 @@ static int add_rule(struct udev_rules *rules, char *line, } if (streq(key, "SYMLINK")) { + if (op == OP_REMOVE) { + log_error("invalid SYMLINK operation"); + goto invalid; + } if (op < OP_MATCH_MAX) rule_add_key(&rule_tmp, TK_M_DEVLINK, op, value, NULL); else @@ -1383,6 +1432,11 @@ static int add_rule(struct udev_rules *rules, char *line, uid_t uid; char *endptr; + if (op == OP_REMOVE) { + log_error("invalid OWNER operation"); + goto invalid; + } + uid = strtoul(value, &endptr, 10); if (endptr[0] == '\0') { rule_add_key(&rule_tmp, TK_A_OWNER_ID, op, NULL, &uid); @@ -1400,6 +1454,11 @@ static int add_rule(struct udev_rules *rules, char *line, gid_t gid; char *endptr; + if (op == OP_REMOVE) { + log_error("invalid GROUP operation"); + goto invalid; + } + gid = strtoul(value, &endptr, 10); if (endptr[0] == '\0') { rule_add_key(&rule_tmp, TK_A_GROUP_ID, op, NULL, &gid); @@ -1417,6 +1476,11 @@ static int add_rule(struct udev_rules *rules, char *line, mode_t mode; char *endptr; + if (op == OP_REMOVE) { + log_error("invalid MODE operation"); + goto invalid; + } + mode = strtol(value, &endptr, 8); if (endptr[0] == '\0') rule_add_key(&rule_tmp, TK_A_MODE_ID, op, NULL, &mode); @@ -1429,6 +1493,11 @@ static int add_rule(struct udev_rules *rules, char *line, if (streq(key, "OPTIONS")) { const char *pos; + if (op == OP_REMOVE) { + log_error("invalid OPTIONS operation"); + goto invalid; + } + pos = strstr(value, "link_priority="); if (pos != NULL) { int prio = atoi(&pos[strlen("link_priority=")]); @@ -2320,7 +2389,10 @@ int udev_rules_apply_to_event(struct udev_rules *rules, log_error("ignoring invalid tag name '%s'", tag); break; } - udev_device_add_tag(event->dev, tag); + if (cur->key.op == OP_REMOVE) + udev_device_remove_tag(event->dev, tag); + else + udev_device_add_tag(event->dev, tag); break; } case TK_A_NAME: { -- cgit v1.2.3-54-g00ecf