X-Git-Url: https://the.earth.li/gitweb/?p=mqtt-arp.git;a=blobdiff_plain;f=mqtt-arp.c;h=2836366b40391dfa6d9373e8fb9e316268f91d28;hp=9d4887012b8bcb826730878698ae7481bff318f2;hb=939e344284056025f919de31e56ac4e7a7ea71e2;hpb=01910e71be0abe5b89670704fc698da9dd0d29af
diff --git a/mqtt-arp.c b/mqtt-arp.c
index 9d48870..2836366 100644
--- a/mqtt-arp.c
+++ b/mqtt-arp.c
@@ -16,6 +16,10 @@
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*/
+#include
+#include
+#include
+#include
#include
#include
#include
@@ -31,12 +35,19 @@
#include
-#define MQTT_HOST "mqtt-host"
-#define MQTT_PORT 8883
-#define MQTT_USERNAME "username"
-#define MQTT_PASSWORD "password"
-#define MQTT_TOPIC "location/by-mac"
-#define LOCATION "home"
+/* Defaults. All overridable from command line. */
+#define MQTT_HOST "mqtt-host"
+#define MQTT_PORT 8883
+#define MQTT_TOPIC "location/by-mac"
+#define LOCATION "home"
+#define CONFIG_FILE "/etc/mqtt-arp.conf"
+
+/* How often (in seconds) to report that we see a device */
+#define REPORT_INTERVAL (2 * 60)
+/* How long to wait without seeing a device before reporting it's gone */
+#define EXPIRY_TIME (10 * 60)
+/* Maximum number of MAC addresses to watch for */
+#define MAX_MACS 8
struct mac_entry {
bool valid;
@@ -45,13 +56,24 @@ struct mac_entry {
time_t last_reported;
};
+struct ma_config {
+ char *mqtt_host;
+ int mqtt_port;
+ char *mqtt_username;
+ char *mqtt_password;
+ char *mqtt_topic;
+ char *location;
+ char *capath;
+ struct mac_entry macs[MAX_MACS];
+};
+
bool debug = false;
+bool want_shutdown = false;
-struct mac_entry macs[] = {
- { true, { 0x11, 0x22, 0x33, 0x44, 0x55, 0x66 }, 0, 0 },
- { true, { 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff }, 0, 0 },
- { false }
-};
+void shutdown_request(int signal)
+{
+ want_shutdown = true;
+}
bool mac_compare(uint8_t *a, uint8_t *b)
{
@@ -69,7 +91,8 @@ bool mac_compare(uint8_t *a, uint8_t *b)
return true;
}
-int mqtt_mac_presence(struct mosquitto *mosq, uint8_t *mac, bool present)
+int mqtt_mac_presence(struct ma_config *config, struct mosquitto *mosq,
+ uint8_t *mac, bool present)
{
char topic[128];
int ret;
@@ -79,25 +102,25 @@ int mqtt_mac_presence(struct mosquitto *mosq, uint8_t *mac, bool present)
t = time(NULL);
i = 0;
- while (macs[i].valid) {
- if (mac_compare(mac, macs[i].mac))
+ while (i < MAX_MACS && config->macs[i].valid) {
+ if (mac_compare(mac, config->macs[i].mac))
break;
i++;
}
- if (!macs[i].valid)
+ if (i >= MAX_MACS || !config->macs[i].valid)
return 0;
- macs[i].last_seen = t;
+ config->macs[i].last_seen = t;
/* Report no more often than every 2 minutes */
- if (present && macs[i].last_reported + 60 * 2 > t)
+ if (present && config->macs[i].last_reported + REPORT_INTERVAL > t)
return 0;
- macs[i].last_reported = t;
+ config->macs[i].last_reported = t;
snprintf(topic, sizeof(topic),
"%s/%02X:%02X:%02X:%02X:%02X:%02X",
- MQTT_TOPIC,
+ config->mqtt_topic,
mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
if (debug)
@@ -105,7 +128,8 @@ int mqtt_mac_presence(struct mosquitto *mosq, uint8_t *mac, bool present)
if (present)
ret = mosquitto_publish(mosq, NULL, topic,
- strlen(LOCATION), LOCATION, 0, 0);
+ strlen(config->location), config->location,
+ 0, 0);
else
ret = mosquitto_publish(mosq, NULL, topic,
strlen("unknown"), "unknown", 0, 0);
@@ -113,7 +137,7 @@ int mqtt_mac_presence(struct mosquitto *mosq, uint8_t *mac, bool present)
return ret;
}
-void prune_macs(struct mosquitto *mosq)
+void prune_macs(struct ma_config *config, struct mosquitto *mosq)
{
time_t t;
int i;
@@ -121,12 +145,14 @@ void prune_macs(struct mosquitto *mosq)
t = time(NULL);
i = 0;
- while (macs[i].valid) {
- /* Expire after 5 minutes */
- if (macs[i].last_seen && macs[i].last_seen + 60 * 5 < t) {
- mqtt_mac_presence(mosq, macs[i].mac, false);
- macs[i].last_seen = 0;
- macs[i].last_reported = 0;
+ while (i < MAX_MACS && config->macs[i].valid) {
+ /* Expire if we haven't seen MAC in EXPIRY_TIME */
+ if (config->macs[i].last_seen &&
+ config->macs[i].last_seen + EXPIRY_TIME < t) {
+ mqtt_mac_presence(config, mosq,
+ config->macs[i].mac, false);
+ config->macs[i].last_seen = 0;
+ config->macs[i].last_reported = 0;
}
i++;
}
@@ -139,64 +165,19 @@ void mosq_log_callback(struct mosquitto *mosq, void *userdata, int level,
printf("%i:%s\n", level, str);
}
-int main(int argc, char *argv[])
+void main_loop(struct ma_config *config, struct mosquitto *mosq, int sock)
{
- int ret, sock;
- struct sockaddr_nl group_addr;
- struct nlmsghdr *hdr;
uint8_t buf[4096];
- ssize_t received;
+ uint8_t *data;
+ struct nlmsghdr *hdr;
struct ndmsg *nd;
struct nlattr *attr;
- uint8_t *data;
+ ssize_t received;
time_t t;
- struct mosquitto *mosq;
-
- bzero(&group_addr, sizeof(group_addr));
- group_addr.nl_family = AF_NETLINK;
- group_addr.nl_pid = getpid();
- group_addr.nl_groups = RTMGRP_NEIGH;
-
- sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
- if (sock < 0) {
- perror("Couldn't open netlink socket");
- exit(EXIT_FAILURE);
- }
-
- if (bind(sock, (struct sockaddr *) &group_addr,
- sizeof(group_addr)) < 0) {
- perror("Failed to bind to netlink socket");
- exit(EXIT_FAILURE);
- }
-
- mosquitto_lib_init();
- mosq = mosquitto_new("mqtt-arp", true, NULL);
- if (!mosq) {
- printf("Couldn't allocate mosquitto structure\n");
- exit(EXIT_FAILURE);
- }
-
- mosquitto_log_callback_set(mosq, mosq_log_callback);
-
- mosquitto_username_pw_set(mosq, MQTT_USERNAME, MQTT_PASSWORD);
- mosquitto_tls_set(mosq, "/etc/ssl/certs/ca-certificates.crt",
- NULL, NULL, NULL, NULL);
-
- ret = mosquitto_connect(mosq, MQTT_HOST, MQTT_PORT, 60);
- if (ret) {
- printf("Unable to connect to MQTT server.\n");
- exit(EXIT_FAILURE);
- }
-
- ret = mosquitto_loop_start(mosq);
- if (ret) {
- printf("Unable to start Mosquitto loop.\n");
- exit(EXIT_FAILURE);
- }
hdr = (struct nlmsghdr *) buf;
nd = (struct ndmsg *) (hdr + 1);
- while (1) {
+ while (!want_shutdown) {
received = recv(sock, buf, sizeof(buf), 0);
if (debug) {
t = time(NULL);
@@ -219,22 +200,247 @@ int main(int argc, char *argv[])
nd->ndm_type);
}
attr = (struct nlattr *) (nd + 1);
- while (attr->nla_len > 0) {
- data = (((uint8_t *) attr) + 4);
+ while (((uint8_t *) attr - buf) < hdr->nlmsg_len) {
+ data = (((uint8_t *) attr) + NLA_HDRLEN);
if (attr->nla_type == NDA_LLADDR &&
nd->ndm_state == NUD_REACHABLE) {
- mqtt_mac_presence(mosq, data, true);
+ mqtt_mac_presence(config, mosq,
+ data, true);
}
- attr = (struct nlattr *)
- (((uint8_t *) attr) + attr->nla_len);
+ attr = (struct nlattr *) (((uint8_t *) attr) +
+ NLA_ALIGN(attr->nla_len));
}
break;
case RTM_DELNEIGH:
case RTM_GETNEIGH:
+ break;
default:
printf("Unknown message type: %d\n", hdr->nlmsg_type);
}
- prune_macs(mosq);
+ prune_macs(config, mosq);
}
+
+}
+
+struct mosquitto *mqtt_init(struct ma_config *config)
+{
+ struct mosquitto *mosq;
+ int ret;
+
+ mosquitto_lib_init();
+ mosq = mosquitto_new("mqtt-arp", true, NULL);
+ if (!mosq) {
+ printf("Couldn't allocate mosquitto structure\n");
+ exit(EXIT_FAILURE);
+ }
+
+ mosquitto_log_callback_set(mosq, mosq_log_callback);
+
+ /* DTRT if username is NULL */
+ mosquitto_username_pw_set(mosq,
+ config->mqtt_username,
+ config->mqtt_password);
+ if (config->capath)
+ mosquitto_tls_set(mosq, config->capath,
+ NULL, NULL, NULL, NULL);
+
+ ret = mosquitto_connect(mosq, config->mqtt_host,
+ config->mqtt_port, 60);
+ if (ret) {
+ printf("Unable to connect to MQTT server.\n");
+ exit(EXIT_FAILURE);
+ }
+
+ ret = mosquitto_loop_start(mosq);
+ if (ret) {
+ printf("Unable to start Mosquitto loop.\n");
+ exit(EXIT_FAILURE);
+ }
+
+ return mosq;
+}
+
+int netlink_init(void)
+{
+ int sock;
+ struct sockaddr_nl group_addr;
+
+ bzero(&group_addr, sizeof(group_addr));
+ group_addr.nl_family = AF_NETLINK;
+ group_addr.nl_pid = getpid();
+ group_addr.nl_groups = RTMGRP_NEIGH;
+
+ sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+ if (sock < 0) {
+ perror("Couldn't open netlink socket");
+ exit(EXIT_FAILURE);
+ }
+
+ if (bind(sock, (struct sockaddr *) &group_addr,
+ sizeof(group_addr)) < 0) {
+ perror("Failed to bind to netlink socket");
+ exit(EXIT_FAILURE);
+ }
+
+ return sock;
+}
+
+int read_config(char *file, struct ma_config *config, int *macs)
+{
+ FILE *f;
+ char line[256];
+ int i;
+
+ f = fopen(file, "r");
+ if (f == NULL)
+ return errno;
+
+#define INT_OPTION(opt, var) \
+ if (strncmp(line, opt " ", sizeof(opt)) == 0) { \
+ var = atoi(&line[sizeof(opt)]); \
+ }
+#define STRING_OPTION(opt, var) \
+ if (strncmp(line, opt " ", sizeof(opt)) == 0) { \
+ var = strdup(&line[sizeof(opt)]); \
+ }
+
+ while (fgets(line, sizeof(line), f) != NULL) {
+ for (i = strlen(line) - 1; i >= 0 && isspace(line[i]); i--)
+ line[i] = '\0';
+ if (line[0] == '\0' || line[0] == '#')
+ continue;
+
+ if (strncmp(line, "mac ", 4) == 0) {
+ if (*macs >= MAX_MACS) {
+ printf("Can only accept %d MAC addresses to"
+ " watch for.\n", MAX_MACS);
+ exit(EXIT_FAILURE);
+ }
+ sscanf(&line[4],
+ "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx",
+ &config->macs[*macs].mac[0],
+ &config->macs[*macs].mac[1],
+ &config->macs[*macs].mac[2],
+ &config->macs[*macs].mac[3],
+ &config->macs[*macs].mac[4],
+ &config->macs[*macs].mac[5]);
+ config->macs[*macs].valid = true;
+ (*macs)++;
+ } else
+ STRING_OPTION("mqtt_host", config->mqtt_host) else
+ INT_OPTION("mqtt_port", config->mqtt_port) else
+ STRING_OPTION("mqtt_user", config->mqtt_username) else
+ STRING_OPTION("mqtt_pass", config->mqtt_password) else
+ STRING_OPTION("mqtt_topic", config->mqtt_topic) else
+ STRING_OPTION("location", config->location) else
+ STRING_OPTION("capath", config->capath)
+ }
+ fclose(f);
+
+ return 0;
+}
+
+struct option long_options[] = {
+ { "capath", required_argument, 0, 'c' },
+ { "host", required_argument, 0, 'h' },
+ { "location", required_argument, 0, 'l' },
+ { "mac", required_argument, 0, 'm' },
+ { "password", required_argument, 0, 'P' },
+ { "port", required_argument, 0, 'p' },
+ { "topic", required_argument, 0, 't' },
+ { "username", required_argument, 0, 'u' },
+ { "verbose", no_argument, 0, 'v' },
+ { 0, 0, 0, 0 }
+};
+
+int main(int argc, char *argv[])
+{
+ int sock;
+ struct mosquitto *mosq;
+ struct ma_config config;
+ int option_index = 0;
+ int macs = 0;
+ char c;
+
+ bzero(&config, sizeof(config));
+ config.mqtt_port = MQTT_PORT;
+
+ /* Read config before parsing command line */
+ read_config(CONFIG_FILE, &config, &macs);
+
+ while (1) {
+ c = getopt_long(argc, argv, "c:h:l:m:p:P:t:u:v",
+ long_options, &option_index);
+
+ if (c == -1)
+ break;
+
+ switch (c) {
+ case 'c':
+ config.capath = optarg;
+ break;
+ case 'h':
+ config.mqtt_host = optarg;
+ break;
+ case 'l':
+ config.location = optarg;
+ break;
+ case 'm':
+ if (macs >= MAX_MACS) {
+ printf("Can only accept %d MAC addresses to"
+ " watch for.\n", MAX_MACS);
+ exit(EXIT_FAILURE);
+ }
+ sscanf(optarg,
+ "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx",
+ &config.macs[macs].mac[0],
+ &config.macs[macs].mac[1],
+ &config.macs[macs].mac[2],
+ &config.macs[macs].mac[3],
+ &config.macs[macs].mac[4],
+ &config.macs[macs].mac[5]);
+ config.macs[macs].valid = true;
+ macs++;
+ break;
+ case 'p':
+ config.mqtt_port = atoi(optarg);
+ break;
+ case 'P':
+ config.mqtt_password = optarg;
+ break;
+ case 't':
+ config.mqtt_topic = optarg;
+ break;
+ case 'u':
+ config.mqtt_username = optarg;
+ break;
+ case 'v':
+ debug = true;
+ break;
+ default:
+ printf("Unrecognized option: %c\n", c);
+ exit(EXIT_FAILURE);
+ }
+ }
+
+ if (!config.mqtt_host)
+ config.mqtt_host = MQTT_HOST;
+ if (!config.mqtt_topic)
+ config.mqtt_topic = MQTT_TOPIC;
+ if (!config.location)
+ config.location = LOCATION;
+
+ signal(SIGTERM, shutdown_request);
+
+ sock = netlink_init();
+ mosq = mqtt_init(&config);
+
+ main_loop(&config, mosq, sock);
+
+ mosquitto_disconnect(mosq);
+ mosquitto_loop_stop(mosq, true);
+ mosquitto_destroy(mosq);
+ mosquitto_lib_cleanup();
+ close(sock);
}