bugfix: I forgot to change the content-length when I did a replacemen…

…t, leading to timeouts

notify-forwarder.c

@@ -133,7 +133,23 @@ int main(int argc, char** argv) {
             printf("strange, no request.... %s\n", strerror(errno));
             continue;
         }
-        char* send_buffer = str_replace(request, sonos_box_ip_address, outside_nat_ip_address);
+        char* send_buffer = str_replace(request, sonos_box_ip_address, outside_nat_ip_address, STR_REPLACE_REPLACE_ALL);
+        long lengthdifference = strlen(send_buffer) - strlen(request);
+        if (lengthdifference) {
+            //update the content-length header
+            int oldlength = get_content_length(send_buffer);
+            char* cl_start = strstr(send_buffer, CONTENT_LENGTH_LINE);
+            char* cl_end = strstr(cl_start + strlen(CONTENT_LENGTH_LINE), "\r\n");
+            char* replace_from = calloc(cl_end - cl_start + 1, sizeof(char));
+            strncpy(replace_from, cl_start, cl_end-cl_start);
+            char* replace_with;
+            asprintf(&replace_with, "%s %ld", CONTENT_LENGTH_LINE, oldlength + lengthdifference);
+            char* new_send_buffer = str_replace(send_buffer, replace_from, replace_with, 1);
+            free(replace_from);
+            free(replace_with);
+            free(send_buffer);
+            send_buffer = new_send_buffer;
+        }
         char* host = get_host(send_buffer);
         unsigned short port = get_port(send_buffer);
         fill_socketaddr_in(&forward_destination_address, port, host);

sonos-forwarder.c

@@ -98,7 +98,7 @@ int main(int argc, char** argv) {
                 printf("no reply\n");
             } else {
                 int send_buffer_size = nr_bytes_received - strlen(to_replace) + strlen(replace_with) + 1;
-                char* send_buffer = str_replace(receive_buffer, to_replace, replace_with);
+                char* send_buffer = str_replace(receive_buffer, to_replace, replace_with, STR_REPLACE_REPLACE_ALL);
                 sendto(forward_reply_socket, send_buffer, send_buffer_size, 0, (struct sockaddr*) &remote_address, remote_address_length); 
                 free(send_buffer);
                 printf("Message %s <-- internal\n", inet_ntoa(remote_address.sin_addr));

str_replace.c

@@ -3,7 +3,7 @@
 #include <stdlib.h>
 
 // You must free the result if result is non-NULL.
-char *str_replace(const char *orig, const char *rep, const char *with) {
+char *str_replace(const char *orig, const char *rep, const char *with, unsigned int max_replacements) {
     char *result; // the return string
     const char *ins;    // the next insert point
     char *tmp;    // varies
@@ -17,6 +17,9 @@ char *str_replace(const char *orig, const char *rep, const char *with) {
     if (!rep)
         rep = "";
     len_rep = strlen(rep);
+    if (!len_rep) {
+        return NULL; //undefined, how can we replace nothing with something
+    }
     if (!with)
         with = "";
     len_with = strlen(with);
@@ -26,6 +29,10 @@ char *str_replace(const char *orig, const char *rep, const char *with) {
         ins = tmp + len_rep;
     }
 
+    if (max_replacements != 0 && count > max_replacements) {
+        count = max_replacements;
+    }
+
     // first time through the loop, all the variable are set correctly
     // from here on,
     //    tmp points to the end of the result string

str_replace.h

@@ -1 +1,6 @@
-char *str_replace(const char *orig, const char *rep, const char *with);
+/**
+ * Replaces occurences of one string with the next. Returns a new char* which needs to be free'd later
+ * if max_replacements == STR_REPLACE_REPLACE_ALL, then all occurences are replaced
+ **/
+#define STR_REPLACE_REPLACE_ALL 0
+char *str_replace(const char *orig, const char *rep, const char *with, unsigned int max_replacements);