diff options
Diffstat (limited to 'src/udev/udev-rules.c')
| -rw-r--r-- | src/udev/udev-rules.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/src/udev/udev-rules.c b/src/udev/udev-rules.c index bf997fc0ed..a02a7a1bc6 100644 --- a/src/udev/udev-rules.c +++ b/src/udev/udev-rules.c @@ -78,6 +78,7 @@ typedef enum { TK_M_TAG, /* strv, sd_device_get_tag_first(), sd_device_get_tag_next() */ TK_M_SUBSYSTEM, /* string, sd_device_get_subsystem() */ TK_M_DRIVER, /* string, sd_device_get_driver() */ + TK_M_WAITFOR, TK_M_ATTR, /* string, takes filename through attribute, sd_device_get_sysattr_value(), udev_resolve_subsys_kernel(), etc. */ TK_M_SYSCTL, /* string, takes kernel parameter through attribute */ @@ -415,6 +416,47 @@ static void rule_line_append_token(UdevRuleLine *rule_line, UdevRuleToken *token rule_line->current_token = token; } +#define WAIT_LOOP_PER_SECOND 50 +static int wait_for_file(sd_device *dev, const char *file, int timeout) { + char filepath[UDEV_PATH_SIZE]; + char devicepath[UDEV_PATH_SIZE]; + struct stat stats; + int loop = timeout * WAIT_LOOP_PER_SECOND; + + /* a relative path is a device attribute */ + devicepath[0] = '\0'; + if (file[0] != '/') { + const char *val; + int r; + + r = sd_device_get_syspath(dev, &val); + if (r < 0) + return r; + strscpyl(devicepath, sizeof(devicepath), val, NULL); + strscpyl(filepath, sizeof(filepath), devicepath, "/", file, NULL); + file = filepath; + } + + while (--loop) { + const struct timespec duration = { 0, 1000 * 1000 * 1000 / WAIT_LOOP_PER_SECOND }; + + /* lookup file */ + if (stat(file, &stats) == 0) { + log_debug("file '%s' appeared after %i loops", file, (timeout * WAIT_LOOP_PER_SECOND) - loop-1); + return 0; + } + /* make sure, the device did not disappear in the meantime */ + if (devicepath[0] != '\0' && stat(devicepath, &stats) != 0) { + log_debug("device disappeared while waiting for '%s'", file); + return -2; + } + log_debug("wait for '%s' for %i mseconds", file, 1000 / WAIT_LOOP_PER_SECOND); + nanosleep(&duration, NULL); + } + log_debug("waiting for '%s' failed", file); + return -1; +} + static int rule_line_add_token(UdevRuleLine *rule_line, UdevRuleTokenType type, UdevRuleOperatorType op, char *value, void *data) { UdevRuleToken *token; UdevRuleMatchType match_type = _MATCH_TYPE_INVALID; @@ -957,6 +999,12 @@ static int parse_token(UdevRules *rules, const char *key, char *attr, UdevRuleOp r = rule_line_add_token(rule_line, TK_A_RUN_BUILTIN, op, value, UDEV_BUILTIN_CMD_TO_PTR(cmd)); } else return log_token_invalid_attr(rules, key); + } else if (streq(key, "WAIT_FOR") || streq(key, "WAIT_FOR_SYSFS")) { + if (op == OP_REMOVE) + return log_token_invalid_op(rules, key); + + rule_line_add_token(rule_line, TK_M_WAITFOR, 0, value, NULL); + return 1; } else if (streq(key, "GOTO")) { if (attr) return log_token_invalid_attr(rules, key); @@ -1643,6 +1691,14 @@ static int udev_rule_apply_token_to_event( return token_match_string(token, val); } + case TK_M_WAITFOR: { + char filename[UDEV_PATH_SIZE]; + int found; + + udev_event_apply_format(event, token->value, filename, sizeof(filename), false); + found = (wait_for_file(event->dev, filename, 10) == 0); + return found || (token->op == OP_NOMATCH); + } case TK_M_ATTR: case TK_M_PARENTS_ATTR: return token_match_attr(token, dev, event); |