Add logline reading and fifo support.

1 files changed, 159 insertions, 20 deletions

diff --git a/src/bsnmp-regex.c b/src/bsnmp-regex.c
index 785659b..93b9ac2 100644
--- a/src/bsnmp-regex.c
+++ b/src/bsnmp-regex.c
@@ -3,10 +3,12 @@
 
 #include <sys/queue.h>
 #include <sys/select.h>
+#include <sys/stat.h>
 #include <syslog.h>
 #include <unistd.h>
 #include <stdarg.h>
 #include <ctype.h>
+#include <fcntl.h>
 
 #include <bsnmp/snmpmod.h>
 #include <pcre.h>
@@ -15,6 +17,7 @@
 #include "regex_oid.h"
 
 #define DEFAULT_CONFIG      CONF_PREFIX "/rrdbot"
+#define DEFAULT_FIFO        "/var/run/snmp-regex.fifo"  /* TODO: Configure this properly */
 
 /* our module handle */
 static struct lmodule *module;
@@ -53,11 +56,19 @@ TAILQ_HEAD(data_entry_list, data_entry);
 static struct data_entry_list entries = TAILQ_HEAD_INITIALIZER(entries);
 static uint32_t entry_count = 0;
 
-static char *config_memory = NULL;
 
 /* configuration */
 static u_char *regex_config = NULL;
+static char *config_memory = NULL;
+
+/* The FIFO log */
 static u_char *regex_fifo = NULL;
+static int fifo_fd = -1;
+static void *fifo_sel = NULL;
+
+/* Buffer for parsing logs */
+#define LINE_LENGTH 1024
+static char line_buffer[LINE_LENGTH];
 
 /* -----------------------------------------------------------------------------
  * HELPERS
@@ -112,6 +123,129 @@ strtrim (char* data)
 }
 
 /* -----------------------------------------------------------------------------
+ * LOG READING AND MATCHING
+ */
+
+static void
+close_fifo ()
+{
+    if (fifo_sel) {
+        fd_deselect (fifo_sel);
+        fifo_sel = NULL;
+    }
+
+    if (fifo_fd != -1) {
+        close (fifo_fd);
+        fifo_fd = -1;
+    }
+
+    memset (line_buffer, 0, sizeof (line_buffer));
+}
+
+static void
+process_log (char *line)
+{
+    fprintf (stderr, "log line: %s\n", line);
+}
+
+static void
+receive_log (int fd, void *data)
+{
+    char *t;
+    int len;
+    int r, l;
+
+    ASSERT (fd == fifo_fd);
+
+    len = strlen (line_buffer);
+    ASSERT (len < LINE_LENGTH);
+
+    do {
+        r = read (fd, line_buffer + len, (LINE_LENGTH - 1) - len);
+
+        if (r < 0 && errno != EAGAIN) {
+            emsg ("couldn't read from fifo: %s: %s", regex_fifo, strerror (errno));
+            return;
+
+        /* Got data, null terminate */
+        } else if (r > 0) {
+            len += r;
+            ASSERT (len < LINE_LENGTH);
+            line_buffer[len] = 0;
+        }
+
+        /* Break really long lines */
+        if (len >= LINE_LENGTH - 1)
+            line_buffer[len - 1] = '\n';
+
+        for (;;) {
+            t = strchr (line_buffer, '\n');
+            if (t == NULL)
+                break;
+
+            /* Break line (also DOS line) */
+            *t = 0;
+            if (line_buffer != t && *(t - 1) == '\r')
+                *(t - 1) = 0;
+
+            /* Send it off */
+            process_log (line_buffer);
+
+            /* Move data to front of buffer */
+            l = (t + 1) - line_buffer;
+            ASSERT (l <= len);
+            memmove (line_buffer, t + 1, (len - l) + 1);
+            len -= l;
+        }
+
+    } while (r > 0);
+}
+
+static int
+open_fifo ()
+{
+    struct stat sb;
+
+    close_fifo ();
+
+    ASSERT (regex_fifo && regex_fifo[0]);
+
+    if (stat (regex_fifo, &sb) == 0) {
+        /* Complain if it's not a FIFO */
+        if (!S_ISFIFO (sb.st_mode)) {
+            emsg ("file or directory already exists: %s", regex_fifo);
+            return -1;
+        }
+
+    } else if (errno != ENOENT) {
+        /* Try and create it */
+        if (mkfifo (regex_fifo, S_IRWXU | S_IRWXG | S_IRWXO) < 0) {
+            emsg ("couldn't create fifo: %s: %s", regex_fifo, strerror (errno));
+            return -1;
+        }
+
+    } else {
+        emsg ("couldn't access fifo: %s: %s", regex_fifo, strerror (errno));
+        return -1;
+    }
+
+    fifo_fd = open (regex_fifo, O_RDONLY);
+    if (fifo_fd < 0) {
+        emsg ("couldn't open fifo: %s: %s", regex_fifo, strerror (errno));
+        return -1;
+    }
+
+    fifo_sel = fd_select (fifo_fd, receive_log, NULL, module);
+    if (!fifo_sel) {
+        emsg ("couldn't listen on fifo: %s: %s", regex_fifo, strerror (errno));
+        return -1;
+    }
+
+    memset (line_buffer, 0, sizeof (line_buffer));
+    return 0;
+}
+
+/* -----------------------------------------------------------------------------
  * CONFIG PARSING
  */
 
@@ -271,9 +405,7 @@ config_read ()
     FILE *f = NULL;
     long len;
 
-    /* XXXXXXXXXXXxx Move DEFAULT_CONFIG settings to init */
-    if (!regex_config || !regex_config[0])
-        regex_config = DEFAULT_CONFIG;
+    ASSERT (regex_config && regex_config[0]);
 
     f = fopen (regex_config, "r");
     if (f == NULL) {
@@ -378,7 +510,7 @@ op_regexconfig (struct snmp_context *ctx, struct snmp_value *value,
                 u_int sub, u_int iidx, enum snmp_op op)
 {
     asn_subid_t which = value->var.subs[sub - 1];
-    int r;
+    int r = SNMP_ERR_NOERROR;
 
     switch (which) {
     case LEAF_regexConfig:
@@ -392,12 +524,14 @@ op_regexconfig (struct snmp_context *ctx, struct snmp_value *value,
 
         switch (op) {
         case SNMP_OP_SET:
-            if ((r = string_save (value, ctx, -1, &regex_config)) != SNMP_ERR_NOERROR)
-                return r;
-            if (config_parse () < 0) {
-                string_rollback (ctx, &regex_config);
-                return SNMP_ERR_GENERR;
+            if ((r = string_save (value, ctx, -1, &regex_config)) == SNMP_ERR_NOERROR) {
+                if (!regex_config[0])
+                    r = SNMP_ERR_WRONG_VALUE;
+                else if (config_parse () < 0)
+                    r = SNMP_ERR_GENERR;
             }
+            if (r != SNMP_ERR_NOERROR)
+                string_rollback (ctx, &regex_config);
             break;
         case SNMP_OP_COMMIT:
             string_commit (ctx);
@@ -410,7 +544,7 @@ op_regexconfig (struct snmp_context *ctx, struct snmp_value *value,
             break;
         }
 
-        return SNMP_ERR_NOERROR;
+        return r;
 
 
     case LEAF_regexFifo:
@@ -424,13 +558,14 @@ op_regexconfig (struct snmp_context *ctx, struct snmp_value *value,
 
         switch (op) {
         case SNMP_OP_SET:
-            if ((r = string_save (value, ctx, -1, &regex_fifo)) != SNMP_ERR_NOERROR)
-                return r;
-            /* TODO: Make and open the FIFO here....
-            if (config_parse () < 0) {
+            if ((r = string_save (value, ctx, -1, &regex_fifo)) == SNMP_ERR_NOERROR) {
+                if (!regex_fifo[0])
+                    r = SNMP_ERR_WRONG_VALUE;
+                else if (open_fifo () < 0)
+                    r = SNMP_ERR_GENERR;
+            }
+            if (r != SNMP_ERR_NOERROR)
                 string_rollback (ctx, &regex_config);
-                return SNMP_ERR_GENERR;
-            } */
             break;
         case SNMP_OP_COMMIT:
             string_commit (ctx);
@@ -443,7 +578,7 @@ op_regexconfig (struct snmp_context *ctx, struct snmp_value *value,
             break;
         }
 
-        return SNMP_ERR_NOERROR;
+        return r;
     }
 
     ASSERT(0);
@@ -559,11 +694,11 @@ module_init (struct lmodule *mod, int argc, char *argv[])
         return EINVAL;
     }
 
-    regex_config = strdup ("");
+    regex_config = strdup (DEFAULT_CONFIG);
     if (!regex_config)
         return ENOMEM;
 
-    regex_fifo = strdup ("");
+    regex_fifo = strdup (DEFAULT_FIFO);
     if (!regex_fifo) {
         free (regex_config);
         return ENOMEM;
@@ -592,6 +727,10 @@ module_fini (void)
     ASSERT (regex_fifo);
     free (regex_fifo);
 
+    close_fifo ();
+    config_free_all ();
+
+
     return 0;
 }