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--- net-tools-1.60/netstat.c.foo Mon Apr 22 14:25:20 2002
+++ net-tools-1.60/netstat.c Mon Apr 22 14:25:22 2002
@@ -435,6 +435,162 @@
" will not be shown, you would have to be root to see it all.)\n"));
}
+#define TCP_HASH_SIZE 1009
+
+static struct tcp_node {
+ struct tcp_node *next;
+ char *socket_pair;
+} *tcp_node_hash[TCP_HASH_SIZE];
+
+static unsigned int tcp_node_compute_string_hash(const char *p)
+{
+ unsigned int h = *p;
+
+ if (h)
+ for (p += 1; *p != '\0'; p++)
+ h = (h << 5) - h + *p;
+
+ return h;
+}
+
+#define TCP_NODE_HASH_STRING(x) \
+ (tcp_node_compute_string_hash(x) % TCP_HASH_SIZE)
+
+static void tcp_node_hash_clear(void)
+{
+ int i;
+ struct tcp_node *next_node;
+ struct tcp_node *tmp_node;
+ for (i=0; i < TCP_HASH_SIZE; i++) {
+ if (tcp_node_hash[i]) {
+ /* free the children of this hash bucket */
+ next_node = tcp_node_hash[i]->next;
+ while (next_node) {
+ tmp_node = next_node;
+ next_node = next_node->next;
+ free(tmp_node->socket_pair);
+ free(tmp_node);
+ }
+
+ /* free the bucket itself */
+ free(tcp_node_hash[i]);
+ tcp_node_hash[i] = NULL;
+ }
+ }
+}
+
+/* This function takes a socket pair string. If it already exists in
+ the hash it returns -1, otherwise it returns 0. */
+
+static int tcp_node_hash_check_and_append(const char *local_addr,
+ int local_port,
+ const char *rem_addr,
+ int rem_port)
+{
+ unsigned int hash_val;
+ struct tcp_node *tmp_node;
+ int tmp_string_len;
+ char *tmp_string;;
+
+ /* Size of the string is the size of the two lengths of the address
+ strings plus enough sizes for the colons and the ports. */
+ tmp_string_len = strlen(local_addr) + strlen(rem_addr) + 32;
+ tmp_string = malloc(tmp_string_len);
+ if (!tmp_string)
+ return 0;
+
+ if (snprintf(tmp_string, tmp_string_len - 1, "%s:%d:%s:%d",
+ local_addr, local_port, rem_addr, rem_port) < 0) {
+ free(tmp_string);
+ return 0;
+ }
+
+ hash_val = TCP_NODE_HASH_STRING(tmp_string);
+
+ /* See if we have to allocate this node */
+ if (!tcp_node_hash[hash_val]) {
+ tcp_node_hash[hash_val] = malloc(sizeof(struct tcp_node));
+ if (!tcp_node_hash[hash_val]) {
+ free(tmp_string);
+ return 0;
+ }
+
+ memset(tcp_node_hash[hash_val], 0, sizeof(struct tcp_node));
+
+ /* Stuff this new value into the hash bucket and return early */
+ tcp_node_hash[hash_val]->socket_pair = tmp_string;
+ return 0;
+ }
+
+ /* Try to find the value in the hash bucket. */
+ tmp_node = tcp_node_hash[hash_val];
+ while (tmp_node) {
+ if (!strcmp(tmp_node->socket_pair, tmp_string)) {
+ free(tmp_string);
+ return -1;
+ }
+ tmp_node = tmp_node->next;
+ }
+
+ /* If we got this far it means that it isn't in the hash bucket.
+ Add it to the front since it's faster that way. */
+ tmp_node = tcp_node_hash[hash_val];
+
+ tcp_node_hash[hash_val] = malloc(sizeof(struct tcp_node));
+ if (!tcp_node_hash[hash_val]) {
+ free(tmp_string);
+ tcp_node_hash[hash_val] = tmp_node;
+ return 0;
+ }
+
+ tcp_node_hash[hash_val]->socket_pair = tmp_string;
+ tcp_node_hash[hash_val]->next = tmp_node;
+
+ return 0;
+}
+
+#if 0
+static void tcp_node_hash_report_bucket_size(void)
+{
+ int max = 0;
+ int min = 0;
+ int num = 0;
+ int total = 0;
+ struct tcp_node *tmp_node;
+ int tmp, i;
+ float avg;
+
+ for (i=0; i < TCP_HASH_SIZE; i++) {
+ tmp_node = tcp_node_hash[i];
+ if (!tmp_node)
+ continue;
+
+ tmp = 0;
+
+ num++;
+ tmp = 1;
+
+ while (tmp_node) {
+ tmp++;
+ tmp_node = tmp_node->next;
+ }
+
+ total += tmp;
+ if (tmp > max)
+ max = tmp;
+
+ if (min == 0 || tmp < min)
+ min = tmp;
+ }
+
+ avg = (float)total/(float)num;
+
+ printf("%d nodes in %d buckets min/max/avg %d/%d/%.2f\n",
+ total, num, min, max, avg);
+
+}
+#endif
+
#if HAVE_AFNETROM
static const char *netrom_state[] =
{
@@ -752,11 +908,20 @@
fprintf(stderr, _("warning, got bogus tcp line.\n"));
return;
}
+
if ((ap = get_afntype(((struct sockaddr *) &localaddr)->sa_family)) == NULL) {
fprintf(stderr, _("netstat: unsupported address family %d !\n"),
((struct sockaddr *) &localaddr)->sa_family);
return;
}
+
+ /* make sure that we haven't seen this socket pair before */
+ if (tcp_node_hash_check_and_append(local_addr, local_port,
+ rem_addr, rem_port) < 0) {
+ /* fprintf(stderr, _("warning, got duplicate tcp line.\n")); */
+ return;
+ }
+
if (state == TCP_LISTEN) {
time_len = 0;
retr = 0L;
@@ -1849,6 +2014,7 @@
break;
sleep(1);
prg_cache_clear();
+ tcp_node_hash_clear();
}
return (i);
}
|
