Avoid division by zero when calculating CPU usage.

[i3/i3status] / src / print_ipv6_addr.c

diff --git a/src/print_ipv6_addr.c b/src/print_ipv6_addr.c
index bfd985d1a92ebc6e83f3b4aafd358654e197c8ab..b7f668a4a6ba8353405f4a3268b17472ddbbfb17 100644 (file)
--- a/src/print_ipv6_addr.c
+++ b/src/print_ipv6_addr.c
@@ -1,15 +1,21 @@
 // vim:ts=8:expandtab
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
 #include <stdio.h>
 #include <stdbool.h>
 #include <unistd.h>
 #include <stdlib.h>
-#include <sys/types.h>
-#include <sys/socket.h>
 #include <netdb.h>
 #include <string.h>
-#include <arpa/inet.h>
+#include <yajl/yajl_gen.h>
+#include <yajl/yajl_version.h>
+
+#include "i3status.h"
 
-static char * get_sockname(struct addrinfo *addr) {
+static char *get_sockname(struct addrinfo *addr) {
         static char buf[INET6_ADDRSTRLEN+1];
         struct sockaddr_storage local;
         int ret;
@@ -34,7 +40,6 @@ static char * get_sockname(struct addrinfo *addr) {
                 return NULL;
         }
 
-
         socklen_t local_len = sizeof(struct sockaddr_storage);
         if (getsockname(fd, (struct sockaddr*)&local, &local_len) == -1) {
                 perror("getsockname()");
@@ -46,7 +51,7 @@ static char * get_sockname(struct addrinfo *addr) {
         if ((ret = getnameinfo((struct sockaddr*)&local, local_len,
                                buf, sizeof(buf), NULL, 0,
                                NI_NUMERICHOST)) != 0) {
-                fprintf(stderr, "getnameinfo(): %s\n", gai_strerror(ret));
+                fprintf(stderr, "i3status: getnameinfo(): %s\n", gai_strerror(ret));
                 (void)close(fd);
                 return NULL;
         }
@@ -59,7 +64,7 @@ static char * get_sockname(struct addrinfo *addr) {
  * Returns the IPv6 address with which you have connectivity at the moment.
  * The char * is statically allocated and mustn't be freed
  */
-static char *get_ipv6_addr() {
+static char *get_ipv6_addr(void) {
         struct addrinfo hints;
         struct addrinfo *result, *resp;
         static struct addrinfo *cached = NULL;
@@ -71,6 +76,7 @@ static char *get_ipv6_addr() {
 
         memset(&hints, 0, sizeof(struct addrinfo));
         hints.ai_family = AF_INET6;
+        hints.ai_socktype = SOCK_DGRAM;
 
         /* We resolve the K root server to get a public IPv6 address. You can
          * replace this with any other host which has an AAAA record, but the
@@ -84,7 +90,11 @@ static char *get_ipv6_addr() {
 
         for (resp = result; resp != NULL; resp = resp->ai_next) {
                 char *addr_string = get_sockname(resp);
-                if (!addr_string)
+                /* If we could not get our own address and there is more than
+                 * one result for resolving k.root-servers.net, we cannot
+                 * cache. Otherwise, no matter if we got IPv6 connectivity or
+                 * not, we will cache the (single) result and are done. */
+                if (!addr_string && result->ai_next != NULL)
                         continue;
 
                 if ((cached = malloc(sizeof(struct addrinfo))) == NULL)
@@ -103,23 +113,27 @@ static char *get_ipv6_addr() {
         return NULL;
 }
 
-void print_ipv6_info(const char *format_up, const char *format_down) {
+void print_ipv6_info(yajl_gen json_gen, char *buffer, const char *format_up, const char *format_down) {
         const char *walk;
-        char * addr_string = get_ipv6_addr();
-        
+        char *addr_string = get_ipv6_addr();
+        char *outwalk = buffer;
+
         if (addr_string == NULL) {
-                printf("%s", format_down);
-        } else {
-                for (walk = format_up; *walk != '\0'; walk++) {
-                        if (*walk != '%') {
-                                putchar(*walk);
-                                continue;
-                        }
-                        
-                        if (strncmp(walk+1, "ip", strlen("ip")) == 0) {
-                                printf("%s", addr_string);
-                                walk += strlen("ip");
-                        }
+                OUTPUT_FULL_TEXT(format_down);
+                return;
+        }
+
+        for (walk = format_up; *walk != '\0'; walk++) {
+                if (*walk != '%') {
+                        *(outwalk++) = *walk;
+                        continue;
+                }
+
+                if (strncmp(walk+1, "ip", strlen("ip")) == 0) {
+                        outwalk += sprintf(outwalk, "%s", addr_string);
+                        walk += strlen("ip");
                 }
         }
+
+        OUTPUT_FULL_TEXT(buffer);
 }