Changed a few names to consistently use underscores.

[icmpmonitor] / icmpmonitor.c

diff --git a/icmpmonitor.c b/icmpmonitor.c
index 365192f..fe7fb12 100644 (file)
--- a/icmpmonitor.c
+++ b/icmpmonitor.c
@@ -1,5 +1,6 @@
 /*
  * Monitor hosts using ICMP "echo" and notify when down.
 /*
  * Monitor hosts using ICMP "echo" and notify when down.

+ * TODO: Write a better description.

  *
  * © 2019 Aaron Taylor <ataylor at subgeniuskitty dot com>
  * © 1999 Vadim Zaliva <lord@crocodile.org>
  *
  * © 2019 Aaron Taylor <ataylor at subgeniuskitty dot com>
  * © 1999 Vadim Zaliva <lord@crocodile.org>


@@ -23,38 +24,44 @@
 #include <netinet/ip.h>
 #include <netinet/ip_icmp.h>
 #include <errno.h>
 #include <netinet/ip.h>
 #include <netinet/ip_icmp.h>
 #include <errno.h>

-
-#include "cfg.h"
+#include "iniparser/iniparser.h"

 
 #define MAXPACKETSIZE  (65536 - 60 - 8) /* TODO: What are the magic numbers? */
 #define DEFAULTDATALEN (64 - 8)         /* TODO: What are the magic numbers? */
 
 
 #define MAXPACKETSIZE  (65536 - 60 - 8) /* TODO: What are the magic numbers? */
 #define DEFAULTDATALEN (64 - 8)         /* TODO: What are the magic numbers? */
 

+/* Must be larger than the length of the longest configuration key (currently 'start_condition'). */
+#define MAXCONFKEYLEN 20
+
+/* One struct per host as listed in the config file. */

 struct monitor_host {
     /* From the config file */
     char * name;
     int    ping_interval;
     int    max_delay;
 struct monitor_host {
     /* From the config file */
     char * name;
     int    ping_interval;
     int    max_delay;

-    char * upcmd;
-    char * downcmd;
+    char * up_cmd;
+    char * down_cmd;

 
     /* Calculated values */
     int                socket;
     struct timeval     last_ping_received;
     struct timeval     last_ping_sent;
 
     /* Calculated values */
     int                socket;
     struct timeval     last_ping_received;
     struct timeval     last_ping_sent;

-    bool               hostup;
+    bool               host_up;

     struct sockaddr_in dest;
     struct sockaddr_in dest;

-    unsigned int       sentpackets;
-    unsigned int       recvdpackets;
+    unsigned int       sent_packets;
+    unsigned int       recvd_packets;

 
 

-    /* linked list */
+    /* Linked list */

     struct monitor_host * next;
 };
 
     struct monitor_host * next;
 };
 

-/* globals */
-static struct monitor_host ** hosts       = NULL;
-static bool                   verbose     = false;
-static int                    keepBanging = 0;
-static int                    send_delay  = 1;
+/* Globals */
+    /* Since the program is based around signals, a linked list of hosts is maintained here. */
+    static struct monitor_host ** hosts          = NULL;
+    /* Set by command line flags. */
+    static bool                   verbose        = false;
+    static bool                   retry_down_cmd = false;
+    /* TODO: Get rid of this global. */
+    static int                    send_delay     = 1;

 
 /*
  * Checksum routine for Internet Protocol family headers
 
 /*
  * Checksum routine for Internet Protocol family headers


@@ -96,7 +103,7 @@ in_cksum(unsigned short * addr, int len)
  * Modifies out = out - in.
  */
 static void
  * Modifies out = out - in.
  */
 static void

-tvsub(register struct timeval * out, register struct timeval * in)
+tv_sub(register struct timeval * out, register struct timeval * in)

 {
     if ((out->tv_usec -= in->tv_usec) < 0) {
         --out->tv_sec;
 {
     if ((out->tv_usec -= in->tv_usec) < 0) {
         --out->tv_sec;


@@ -126,14 +133,14 @@ pinger(int ignore)
             struct timeval now;
 
             gettimeofday(&now, (struct timezone *) NULL);
             struct timeval now;
 
             gettimeofday(&now, (struct timezone *) NULL);

-            tvsub(&now, &p->last_ping_received);
+            tv_sub(&now, &p->last_ping_received);

 
             if (now.tv_sec > (p->max_delay + p->ping_interval)) {
 
             if (now.tv_sec > (p->max_delay + p->ping_interval)) {

-                if ((p->hostup) || keepBanging) {
+                if ((p->host_up) || retry_down_cmd) {

                     if (verbose) printf("INFO: Host %s stopped responding. Executing DOWN command.\n", p->name);
                     if (verbose) printf("INFO: Host %s stopped responding. Executing DOWN command.\n", p->name);

-                    p->hostup = false;
+                    p->host_up = false;

                     if (!fork()) {
                     if (!fork()) {

-                        system(p->downcmd);
+                        system(p->down_cmd);

                         exit(EXIT_SUCCESS);
                     } else {
                         wait(NULL);
                         exit(EXIT_SUCCESS);
                     } else {
                         wait(NULL);


@@ -142,7 +149,7 @@ pinger(int ignore)
             }
 
             gettimeofday(&now, (struct timezone *) NULL);
             }
 
             gettimeofday(&now, (struct timezone *) NULL);

-            tvsub(&now, &p->last_ping_sent);
+            tv_sub(&now, &p->last_ping_sent);

 
             if (now.tv_sec > p->ping_interval) { /* Time to send ping */
                 icp = (struct icmp *) outpack;
 
             if (now.tv_sec > p->ping_interval) { /* Time to send ping */
                 icp = (struct icmp *) outpack;


@@ -168,7 +175,7 @@ pinger(int ignore)
                 if (i < 0 || i != cc) {
                     if (i<0) fprintf(stderr, "WARN: Failed sending ICMP packet to %s.\n", p->name);
                 }
                 if (i < 0 || i != cc) {
                     if (i<0) fprintf(stderr, "WARN: Failed sending ICMP packet to %s.\n", p->name);
                 }

-                p->sentpackets++;
+                p->sent_packets++;

             }
         }
         p = p->next;
             }
         }
         p = p->next;


@@ -208,19 +215,19 @@ read_icmp_data(struct monitor_host * p)
     }
 
     if (icmp->icmp_type == ICMP_ECHOREPLY && icmp->icmp_id == (getpid() & 0xFFFF) && icmp->icmp_seq == p->socket) {
     }
 
     if (icmp->icmp_type == ICMP_ECHOREPLY && icmp->icmp_id == (getpid() & 0xFFFF) && icmp->icmp_seq == p->socket) {

-        p->recvdpackets++;
+        p->recvd_packets++;

 
         memcpy(&p->last_ping_received, &tv, sizeof(tv));
 
 
         memcpy(&p->last_ping_received, &tv, sizeof(tv));
 

-        tvsub(&tv, (struct timeval *) &icmp->icmp_data[0]);
+        tv_sub(&tv, (struct timeval *) &icmp->icmp_data[0]);

         delay = tv.tv_sec * 1000 + (tv.tv_usec / 1000);
 
         if (verbose) printf("INFO: Got ICMP reply from %s in %d ms.\n", p->name, delay);
         delay = tv.tv_sec * 1000 + (tv.tv_usec / 1000);
 
         if (verbose) printf("INFO: Got ICMP reply from %s in %d ms.\n", p->name, delay);

-        if (!p->hostup) {
+        if (!p->host_up) {

             if (verbose) printf("INFO: Host %s started responding. Executing UP command.\n", p->name);
             if (verbose) printf("INFO: Host %s started responding. Executing UP command.\n", p->name);

-            p->hostup = true;
+            p->host_up = true;

             if (!fork()) {
             if (!fork()) {

-                system(p->upcmd);
+                system(p->up_cmd);

                 exit(EXIT_SUCCESS);
             } else {
                 wait(NULL);
                 exit(EXIT_SUCCESS);
             } else {
                 wait(NULL);


@@ -266,69 +273,81 @@ get_response(void)
     }
 }
 
     }
 }
 

+/*
+ * Parses `config_file` and creates relevant entries under the global variable `hosts`.
+ */

 static void
 static void

-read_hosts(const char * cfg_file_name)
+parse_config(const char * conf_file)

 {
 {

-    int i, n = 0;
-    struct Cfg * cfg;
+    dictionary * conf = iniparser_load(conf_file);
+    if (conf == NULL) {
+        fprintf(stderr, "ERROR: Unable to parse configuration file %s.\n", conf_file);
+        exit(EXIT_FAILURE);
+    }

 
 

-    if ((cfg = readcfg(cfg_file_name)) == NULL) {
-        fprintf(stderr, "ERROR: Failed to read config.\n");
+    int host_count = iniparser_getnsec(conf);
+    if (host_count < 1 ) {
+        fprintf(stderr, "ERROR: Unable to determine number of hosts in configuration file.\n");

         exit(EXIT_FAILURE);
     }
 
         exit(EXIT_FAILURE);
     }
 

-    if (cfg->nelements) {
-        hosts = malloc(sizeof(struct monitor_host *) * cfg->nelements);
-        for (i = 0; i < cfg->nelements; i++) {
-            if (cfg->dict[i]->nvalues < 4) {
-                fprintf(stderr, "ERROR: Not enough fields in record %d of cfg file. Got %d.\n", n, cfg->dict[i]->nvalues+1);
-                exit(EXIT_FAILURE);
-            } else if (cfg->dict[i]->nvalues>5) {
-                fprintf(stderr, "ERROR: Too many fields in record %d of cfg file. Got %d.\n", n, cfg->dict[i]->nvalues+1);
-                exit(EXIT_FAILURE);
+    hosts = malloc(sizeof(struct monitor_host *) * host_count);
+    for (int i=0; i < host_count; i++) {
+        /* Allocate a buffer large enough to hold the full 'section:key' string. */
+        int section_len = strlen(iniparser_getsecname(conf, i));
+        char * key_buf = malloc(section_len + 1 + MAXCONFKEYLEN + 1);
+        strcpy(key_buf, iniparser_getsecname(conf, i));
+        key_buf[section_len++] = ':';
+
+        hosts[i] = malloc(sizeof(struct monitor_host));
+        for (int k=0; k<6; k++) {
+            key_buf[section_len] = '\0'; /* Reuse the section name and colon on each pass through this loop. */
+            switch (k) {
+                case 0:
+                    strncat(key_buf, "host", MAXCONFKEYLEN);
+                    hosts[i]->name = strdup(iniparser_getstring(conf, key_buf, NULL));
+                    break;
+                case 1:
+                    strncat(key_buf, "interval", MAXCONFKEYLEN);
+                    hosts[i]->ping_interval = iniparser_getint(conf, key_buf, -1);
+                    break;
+                case 2:
+                    strncat(key_buf, "max_delay", MAXCONFKEYLEN);
+                    hosts[i]->max_delay = iniparser_getint(conf, key_buf, -1);
+                    break;
+                case 3:
+                    strncat(key_buf, "up_cmd", MAXCONFKEYLEN);
+                    hosts[i]->up_cmd = strdup(iniparser_getstring(conf, key_buf, NULL));
+                    break;
+                case 4:
+                    strncat(key_buf, "down_cmd", MAXCONFKEYLEN);
+                    hosts[i]->down_cmd = strdup(iniparser_getstring(conf, key_buf, NULL));
+                    break;
+                case 5:
+                    /* TODO: Parse for up/down/auto in start_condition. */
+                    /* TODO: Do a host up/down check if necessary. */
+                    hosts[i]->host_up = true;
+                    break;

             }
             }

-
-            hosts[n]                = malloc(sizeof(struct monitor_host));
-            hosts[n]->name          = strdup(cfg->dict[i]->name);
-            hosts[n]->ping_interval = atoi  (cfg->dict[i]->value[0]);
-            hosts[n]->max_delay     = atoi  (cfg->dict[i]->value[1]);
-            hosts[n]->upcmd         = strdup(cfg->dict[i]->value[2]);
-            hosts[n]->downcmd       = strdup(cfg->dict[i]->value[3]);
-
-        if (cfg->dict[i]->nvalues == 4) {
-            hosts[n]->hostup = true;
-        } else if (strcmp(cfg->dict[i]->value[4], "up") == 0) {
-            hosts[n]->hostup = true;
-        } else if (strcmp(cfg->dict[i]->value[4], "down") == 0) {
-            hosts[n]->hostup = false;
-        } else if (strcmp(cfg->dict[i]->value[4], "auto") == 0) {
-            /* TODO: Send a ping and set initial state accordingly. */
-        } else {
-            fprintf(stderr, "ERROR: Illegal value %s in record %d for startup condition.\n", cfg->dict[i]->value[4], n);
-            exit(EXIT_FAILURE);

         }
         }

-            hosts[n]->sentpackets   = 0;
-            hosts[n]->recvdpackets  = 0;
-
-            hosts[n]->socket           = -1;
-            hosts[n]->next             = NULL;
-            if (n > 0) hosts[n-1]->next=hosts[n];
-            gettimeofday(&(hosts[n]->last_ping_received), (struct timezone *)NULL);
-
-            n++;
+        /* TODO: Do I want to make any checks for up_cmd, down_cmd, and start_condition? */
+        if (hosts[i]->name == NULL || hosts[i]->ping_interval == -1 || hosts[i]->max_delay == -1) {
+            fprintf(stderr, "ERROR: Problems parsing section %s.\n", iniparser_getsecname(conf, i));
+            exit(EXIT_FAILURE);

         }
         }

-    }
-
-    freecfg(cfg);

 
 

-    if (n <= 0) {
-        fprintf(stderr, "ERROR: No hosts defined in cfg file, exiting.\n");
-        exit(EXIT_FAILURE);
+        hosts[i]->sent_packets = 0;
+        hosts[i]->recvd_packets = 0;
+        hosts[i]->socket = -1;
+        hosts[i]->next = NULL;
+        if (i>0) hosts[i-1]->next = hosts[i];
+        gettimeofday(&(hosts[i]->last_ping_received), (struct timezone *) NULL);

     }
     }

+    iniparser_freedict(conf);

 }
 
 static int
 }
 
 static int

-gethostaddr(const char * name)
+get_host_addr(const char * name)

 {
     static int res;
     struct hostent * he;
 {
     static int res;
     struct hostent * he;


@@ -364,7 +383,7 @@ init_hosts(void)
     while (p) {
         bzero(&p->dest, sizeof(p->dest));
         p->dest.sin_family = AF_INET;
     while (p) {
         bzero(&p->dest, sizeof(p->dest));
         p->dest.sin_family = AF_INET;

-        if ((p->dest.sin_addr.s_addr = gethostaddr(p->name)) <= 0) {
+        if ((p->dest.sin_addr.s_addr = get_host_addr(p->name)) <= 0) {

             fprintf(stderr, "WARN: Can't resolve host. Skipping client %s.\n", p->name);
             p->socket=-1;
         } else {
             fprintf(stderr, "WARN: Can't resolve host. Skipping client %s.\n", p->name);
             p->socket=-1;
         } else {


@@ -386,37 +405,42 @@ init_hosts(void)
     }
 }
 
     }
 }
 

-int
-main(int argc, char ** argv)
+void
+print_usage(void)

 {
 {

-    extern char * optarg;
-    extern int optind;
-    char * cfgfile = NULL;
-    int param;
+    fprintf(stderr,"Usage: icmpmonitor [-v] [-r] [-f cfgfile]\n");
+}

 
 

+void
+parse_params(int argc, char ** argv)
+{
+    int param;

     while ((param = getopt(argc, argv, "rvf:")) != -1) {
         switch(param) {
             case 'v':
                 verbose = true;
                 break;
             case 'r':
     while ((param = getopt(argc, argv, "rvf:")) != -1) {
         switch(param) {
             case 'v':
                 verbose = true;
                 break;
             case 'r':

-                keepBanging = 1;
+                retry_down_cmd = true;

                 break;
             case 'f':
                 break;
             case 'f':

-                cfgfile=strdup(optarg);
+                parse_config(optarg);

                 break;
             default:
                 break;
             default:

-                fprintf(stderr,"Usage: icmpmonitor [-v] [-r] [-f cfgfile]\n");
+                print_usage();

                 exit(EXIT_FAILURE);
         }
     }
                 exit(EXIT_FAILURE);
         }
     }

-
-    if (!cfgfile) {
-        fprintf(stderr, "ERROR: No config file specified.\n");
+    if (hosts == NULL) {
+        fprintf(stderr, "ERROR: Unable to parse a config file.\n");

         exit(EXIT_FAILURE);
     }
         exit(EXIT_FAILURE);
     }

+}

 
 

-    read_hosts(cfgfile);
+int
+main(int argc, char ** argv)
+{
+    parse_params(argc, argv);

 
     init_hosts();
 
 
     init_hosts();