handle sigpipe error

bird-rtrlib-cli.c

@@ -19,6 +19,8 @@
  * Website: https://github.com/rtrlib/bird-rtrlib-cli
  */
 
+#include <errno.h>
+#include <signal.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -30,44 +32,54 @@
 #include "cli.h"
 #include "config.h"
 #include "rtr.h"
+#include <rtrlib/rtrlib.h>
 
 #define CMD_EXIT "exit"
-
+#define BIRD_RSP_SIZE  (200)
 // Socket to BIRD.
 static int bird_socket = -1;
-
 // Buffer for BIRD commands.
 static char *bird_command = 0;
-
 // Length of buffer for BIRD commands.
 static size_t bird_command_length = -1;
-
 // "add roa" BIRD command "table" part. Defaults to an empty string and becomes
 // "table " + config->bird_roa_table if provided.
 static char *bird_add_roa_table_arg = "";
+// Main configuration.
+static struct config config;
+
+/**
+ * Handle SIGPIPE on bird_socket, write error log entry
+ */
+void sigpipe_handler(int signum)
+{
+    syslog(LOG_ERR, "Caught SIGPIPE %d.", signum);
+}
 
 /**
  * Performs cleanup on resources allocated by `init()`.
  */
-void cleanup(void) {
+void cleanup(void)
+{
     closelog();
 }
 
 /**
  * Frees memory allocated with the " table <bird_roa_table>" clause for the
  * "add roa" BIRD command.
  */
-void cleanup_bird_add_roa_table_arg(void) {
-    // If the buffer is "", it has never been changed, thus there is no malloc'd
-    // buffer.
+void cleanup_bird_add_roa_table_arg(void)
+{
+    // free buffer only, if not empty - i.e., mem was malloc'd
     if (strcmp(bird_add_roa_table_arg, "") != 0)
         free(bird_add_roa_table_arg);
 }
 
 /**
  * Frees memory allocated with the BIRD command buffer.
  */
-void cleanup_bird_command(void) {
+void cleanup_bird_command(void)
+{
     if (bird_command) {
         free(bird_command);
         bird_command = 0;
@@ -78,29 +90,30 @@ void cleanup_bird_command(void) {
 /**
  * Initializes the application prerequisites.
  */
-void init(void) {
+void init(void)
+{
     openlog(NULL, LOG_PERROR | LOG_CONS | LOG_PID, LOG_DAEMON);
 }
 
 /**
  * Creates and populates the "add roa" command's "table" argument buffer.
  * @param bird_roa_table
  */
-void init_bird_add_roa_table_arg(char *bird_roa_table) {
+void init_bird_add_roa_table_arg(char *bird_roa_table)
+{
     // Size of the buffer (" table " + <roa_table> + \0).
     const size_t length = (8 + strlen(bird_roa_table)) * sizeof (char);
-
     // Allocate buffer.
     bird_add_roa_table_arg = malloc(length);
-
     // Populate buffer.
     snprintf(bird_add_roa_table_arg, length, " table %s", bird_roa_table);
 }
 
 /**
  * Creates the buffer for the "add roa" command.
  */
-void init_bird_command(void) {
+void init_bird_command(void)
+{
     // Size of the buffer ("add roa " + <addr> + "/" + <minlen> + " max " +
     // <maxlen> + " as " + <asnum> + <bird_add_roa_table_cmd> + \0)
     bird_command_length = (
@@ -115,7 +128,6 @@ void init_bird_command(void) {
         strlen(bird_add_roa_table_arg) + // length of fixed " table " + <table>
         1 // \0
     ) * sizeof (char);
-
     // Allocate buffer.
     bird_command = malloc(bird_command_length);
 }
@@ -134,13 +146,10 @@ static void pfx_update_callback(struct pfx_table *table,
 {
     // IP address buffer.
     static char ip_addr_str[INET6_ADDRSTRLEN];
-
     // Buffer for BIRD response.
-    static char bird_response[200];
-
+    static char bird_response[BIRD_RSP_SIZE];
     // Fetch IP address as string.
     lrtr_ip_addr_to_str(&(record.prefix), ip_addr_str, sizeof(ip_addr_str));
-
     // Write BIRD command to buffer.
     if (
         snprintf(
@@ -159,14 +168,28 @@ static void pfx_update_callback(struct pfx_table *table,
         syslog(LOG_ERR, "BIRD command too long.");
         return;
     }
-
     // Log the BIRD command and send it to the BIRD server.
     syslog(LOG_INFO, "To BIRD: %s", bird_command);
-    write(bird_socket, bird_command, strlen(bird_command));
-
-    // Fetch the answer and log.
-    bird_response[read(bird_socket, bird_response, sizeof(bird_response)-1)] = 0;
-    syslog(LOG_INFO, "From BIRD: %s", bird_response);
+    // reconnect bird_socket on SIGPIPE error, and resend BIRD command
+    while ((write(bird_socket, bird_command, strlen(bird_command)) < 0) &&
+           (errno == EPIPE)) {
+        syslog(LOG_ERR, "BIRD socket send failed, try reconnect!");
+        close(bird_socket);
+        bird_socket = bird_connect(config.bird_socket_path);
+    }
+    // Fetch BIRD answer, reconnect bird_socket on SIGPIPE while receive
+    int size = -1;
+    while (((size = read(bird_socket, bird_response, BIRD_RSP_SIZE-1)) <0) &&
+           (errno == EPIPE)){
+        syslog(LOG_ERR, "BIRD socket recv failed, try reconnect!");
+        close(bird_socket);
+        bird_socket = bird_connect(config.bird_socket_path);
+    }
+    // log answer, if any valid response
+    if (size > 0) {
+        bird_response[size] = 0;
+        syslog(LOG_INFO, "From BIRD: %s", bird_response);
+    }
 }
 
 /**
@@ -175,53 +198,45 @@ static void pfx_update_callback(struct pfx_table *table,
  * @param argv
  * @return
  */
-int main(int argc, char *argv[]) {
-    // Main configuration.
-    struct config config;
-
+int main(int argc, char *argv[])
+{
     // Buffer for commands and its length.
     char *command = 0;
     size_t command_len = 0;
-
     // Initialize variables.
     config_init(&config);
-
     // Initialize framework.
     init();
-
     // Parse CLI arguments into config and bail out on error.
     if (!parse_cli(argc, argv, &config)) {
         cleanup();
+        fprintf(stderr, "Invalid command line parameter!\n");
         return EXIT_FAILURE;
     }
-
     // Check config.
-    if (!config_check(&config)) {
+    if (config_check(&config)) {
         cleanup();
+        fprintf(stderr, "Invalid configuration parameters!\n");
         return EXIT_FAILURE;
     }
-
     // Setup BIRD ROA table command argument.
     if (config.bird_roa_table) {
         init_bird_add_roa_table_arg(config.bird_roa_table);
     }
-
     // Setup BIRD command buffer.
     init_bird_command();
-
     // Try to connect to BIRD and bail out on failure.
     bird_socket = bird_connect(config.bird_socket_path);
     if (bird_socket == -1) {
         cleanup();
+        fprintf(stderr, "Failed to connect to BIRD socket!\n");
         return EXIT_FAILURE;
     }
 
     struct tr_socket tr_sock;
     struct tr_tcp_config *tcp_config;
     struct tr_ssh_config *ssh_config;
-
-    // Try to connect to the RTR server depending on the requested connection
-    // type.
+    // Try to connect to the RTR server depending on requested connection type.
     switch (config.rtr_connection_type) {
         case tcp:
             tcp_config = rtr_create_tcp_config(
@@ -237,53 +252,56 @@ int main(int argc, char *argv[]) {
             break;
         default:
             cleanup();
+            fprintf(stderr, "Invalid connection type, use tcp or ssh!\n");
             return EXIT_FAILURE;
     }
 
     struct rtr_socket rtr;
     struct rtr_mgr_config *conf;
     struct rtr_mgr_group groups[1];
-
+    // init rtr_socket and groups
     rtr.tr_socket = &tr_sock;
     groups[0].sockets_len = 1;
     groups[0].sockets = malloc(1 * sizeof(rtr));
     groups[0].sockets[0] = &rtr;
     groups[0].preference = 1;
-
+    // init rtr_mgr
     int ret = rtr_mgr_init(&conf, groups, 1, 30, 600, 600,
                            pfx_update_callback, NULL, NULL, NULL);
-
-    if (ret == RTR_ERROR)
-        printf("Error in rtr_mgr_init!\n");
-    else if (ret == RTR_INVALID_PARAM)
-        printf("Invalid params passed to rtr_mgr_init\n");
-
-    if (!conf)
+    // check for init errors
+    if (ret == RTR_ERROR) {
+        fprintf(stderr, "Error in rtr_mgr_init!\n");
         return EXIT_FAILURE;
-
+    }
+    else if (ret == RTR_INVALID_PARAM) {
+        fprintf(stderr, "Invalid params passed to rtr_mgr_init\n");
+        return EXIT_FAILURE;
+    }
+    // check if rtr_mgr config valid
+    if (!conf) {
+        fprintf(stderr, "No config for rtr manager!\n");
+        return EXIT_FAILURE;
+    }
+    // set handler for SIGPIPE
+    signal(SIGPIPE, sigpipe_handler);
+    // start rtr_mgr
     rtr_mgr_start(conf);
-
     // Server loop. Read commands from stdin.
     while (getline(&command, &command_len, stdin) != -1) {
         if (strncmp(command, CMD_EXIT, strlen(CMD_EXIT)) == 0)
             break;
     }
-
     // Clean up RTRLIB memory.
     rtr_mgr_stop(conf);
     rtr_mgr_free(conf);
     free(groups[0].sockets);
-
     // Close BIRD socket.
     close(bird_socket);
-
     // Cleanup memory.
     cleanup_bird_command();
     cleanup_bird_add_roa_table_arg();
-
     // Cleanup framework.
     cleanup();
-
     // Exit with success.
     return EXIT_SUCCESS;
 }

bird.c

@@ -27,38 +27,33 @@
 
 #include "bird.h"
 
-int bird_connect(const char *socket_path) {
+int bird_connect(const char *socket_path)
+{
     // Result value containing the socket to the BIRD.
     int bird_socket = -1;
-
     // Socket address to the BIRD.
     struct sockaddr_un addr;
-
     // Check socket path length.
     if (strlen(socket_path) >= sizeof addr.sun_path) {
         syslog(LOG_EMERG, "Socket path too long");
         return -1;
     }
-
     // Create socket and bail out on error.
     bird_socket = socket(AF_UNIX, SOCK_STREAM, 0);
     if (bird_socket < 0) {
         syslog(LOG_EMERG, "Socket creation error: %m");
         return -1;
     }
-
     // Create socket address.
     memset(&addr, 0, sizeof addr);
     addr.sun_family = AF_UNIX;
     strcpy(addr.sun_path, socket_path);
-
     // Try to connect to BIRD.
     if (connect(bird_socket, (struct sockaddr *) &addr, sizeof addr) == -1) {
         syslog(LOG_EMERG, "BIRD connection to %s failed: %m", socket_path);
         close(bird_socket);
         return -1;
     }
-
     // Return socket.
     return bird_socket;
 }

cli.c

@@ -35,10 +35,10 @@
 #define ARGKEY_RTRSSH_USERNAME 0x103
 
 // Parser function for argp_parse().
-static error_t argp_parser(int key, char *arg, struct argp_state *state) {
+static error_t argp_parser(int key, char *arg, struct argp_state *state)
+{
     // Shortcut to config object passed to argp_parse().
     struct config *config = state->input;
-
     // Process command line argument.
     switch (key) {
         case ARGKEY_BIRD_ROA_TABLE:
@@ -71,13 +71,13 @@ static error_t argp_parser(int key, char *arg, struct argp_state *state) {
             // Process unknown argument.
             return ARGP_ERR_UNKNOWN;
     }
-
     // Return success.
     return 0;
 }
 
 // Parses the specified command line arguments into the program config.
-int parse_cli(int argc, char **argv, struct config *config) {
+int parse_cli(int argc, char **argv, struct config *config)
+{
     // Command line options definition.
     const struct argp_option argp_options[] = {
         {
@@ -150,7 +150,6 @@ int parse_cli(int argc, char **argv, struct config *config) {
         },
         {0}
     };
-
     // argp structure to be passed to argp_parse().
     const struct argp argp = {
         argp_options,
@@ -161,10 +160,8 @@ int parse_cli(int argc, char **argv, struct config *config) {
         NULL,
         NULL
     };
-
     // Parse command line. Exits on errors.
     argp_parse(&argp, argc, argv, 0, NULL, config);
-
     // Return success.
     return 1;
 }