routing/olsrd/patches/004-jsonplugin-http-headers.patch

commit b342385531c18b8afb42db64c7a38d7879668566
Author: Alessio Caiazza <nolith@abisso.org>
Date:   Fri May 16 12:53:15 2014 +0200

    jsoninfo: HTTP headers with CORS (if requested)
    
    The new "httpheaders" parameter prepends HTTP headers to the reply.
    If not set it will default to "no" and have the same behaviour as before.
    Cross-origin resource sharing headers (CORS) are included in reply allowing the
    json retrieval by javascript applications not served by olsrd itself.
    This will allow to easily develop js applications running directly in the
    browser.
    
    Reviewed-by: Ferry Huberts <ferry.huberts@pelagic.nl>

diff --git a/lib/jsoninfo/README_JSONINFO b/lib/jsoninfo/README_JSONINFO
index 709c975..8311ade 100644
--- a/lib/jsoninfo/README_JSONINFO
+++ b/lib/jsoninfo/README_JSONINFO
@@ -73,6 +73,14 @@ LoadPlugin "olsrd_jsoninfo.so.0.0"
     # if you set it to 0.0.0.0, it will accept all connections
     #PlParam      "accept" "0.0.0.0"
 
+    # The "httpheaders" parameter prepends HTTP headers to the reply.
+    # If not set it will default to "no" and have the same behaviour as before.
+    # Among with a minimal set of headers also Cross-origin resource sharing
+    # headers (CORS) are included in reply allowing the json retrieval by
+    # javascript applications not served by olsrd itself.
+    # You can enable it uncommenting the following line:
+    #PlParam      "httpheaders" "yes"
+
     # specify a UUID for this node to track it for debugging
     #PlParam      "UUIDFile" "/etc/olsrd/olsrd.uuid"
 }
diff --git a/lib/jsoninfo/src/olsrd_jsoninfo.c b/lib/jsoninfo/src/olsrd_jsoninfo.c
index 817c64a..f29a37c 100644
--- a/lib/jsoninfo/src/olsrd_jsoninfo.c
+++ b/lib/jsoninfo/src/olsrd_jsoninfo.c
@@ -96,6 +96,9 @@
 
 static int ipc_socket;
 
+/* Response types */
+#define HTTP_200 "HTTP/1.1 200 OK"
+
 /* IPC initialization function */
 static int plugin_ipc_init(void);
 
@@ -126,6 +129,18 @@ static void ipc_print_interfaces(struct autobuf *);
 static void ipc_print_plugins(struct autobuf *);
 static void ipc_print_olsrd_conf(struct autobuf *abuf);
 
+static size_t build_http_header(const char *status, const char *mime,
+  uint32_t msgsize, char *buf, uint32_t bufsize);
+
+/*
+ * this is the size of the buffer used for build_http_header
+ * the amount of data written into the buffer will be less than
+ * 400 bytes approximatively.
+ * The size may vary because the Content-Length header contains
+ * the length of the json data
+ */
+#define MAX_HTTPHEADER_SIZE 512
+
 #define TXT_IPC_BUFSIZE 256
 
 /* these provide all of the runtime status info */
@@ -1282,6 +1297,9 @@ static void
 send_info(unsigned int send_what, int the_socket)
 {
   struct autobuf abuf;
+  size_t header_len = 0;
+  char header_buf[MAX_HTTPHEADER_SIZE];
+  const char *content_type = "application/json";
 
   /* global variables for tracking when to put a comma in for JSON */
   entrynumber[0] = 0;
@@ -1320,12 +1338,17 @@ send_info(unsigned int send_what, int the_socket)
     ipc_print_olsrd_conf(&abuf);
   }
 
-  outbuffer[outbuffer_count] = olsr_malloc(abuf.len, "txt output buffer");
-  outbuffer_size[outbuffer_count] = abuf.len;
+  if(http_headers) {
+    header_len = build_http_header(HTTP_200, content_type, abuf.len, header_buf, sizeof(header_buf));
+  }
+
+  outbuffer[outbuffer_count] = olsr_malloc(header_len + abuf.len, "json output buffer");
+  outbuffer_size[outbuffer_count] = header_len + abuf.len;
   outbuffer_written[outbuffer_count] = 0;
   outbuffer_socket[outbuffer_count] = the_socket;
 
-  memcpy(outbuffer[outbuffer_count], abuf.buf, abuf.len);
+  memcpy(outbuffer[outbuffer_count], header_buf, header_len);
+  memcpy((outbuffer[outbuffer_count]) + header_len, abuf.buf, abuf.len);
   outbuffer_count++;
 
   if (outbuffer_count == 1) {
@@ -1340,6 +1363,53 @@ send_info(unsigned int send_what, int the_socket)
   abuf_free(&abuf);
 }
 
+static size_t
+build_http_header(const char *status, const char *mime, uint32_t msgsize,
+  char *buf, uint32_t bufsize)
+{
+  time_t currtime;
+  size_t size;
+
+  size = snprintf(buf, bufsize, "%s\r\n", status);
+
+  /* Date */
+  time(&currtime);
+  size += strftime(&buf[size], bufsize - size, "Date: %a, %d %b %Y %H:%M:%S GMT\r\n", localtime(&currtime));
+
+  /* Server version */
+  size += snprintf(&buf[size], bufsize - size, "Server: OLSRD JSONInfo plugin\r\n");
+
+  /* connection-type */
+  size += snprintf(&buf[size], bufsize - size, "Connection: closed\r\n");
+
+  /* MIME type */
+  if(mime != NULL) {
+    size += snprintf(&buf[size], bufsize - size, "Content-type: %s\r\n", mime);
+  }
+
+  /* CORS data */
+  /**No needs to be strict here, access control is based on source IP*/
+  size += snprintf(&buf[size], bufsize - size, "Access-Control-Allow-Origin: *\r\n");
+  size += snprintf(&buf[size], bufsize - size, "Access-Control-Allow-Methods: GET, POST, OPTIONS\r\n");
+  size += snprintf(&buf[size], bufsize - size, "Access-Control-Allow-Headers: Accept, Origin, X-Requested-With\r\n");
+  size += snprintf(&buf[size], bufsize - size, "Access-Control-Max-Age: 1728000\r\n");
+
+  /* Content length */
+  if (msgsize > 0) {
+    size += snprintf(&buf[size], bufsize - size, "Content-length: %i\r\n", msgsize);
+  }
+
+  /* Cache-control
+   * No caching dynamic pages
+   */
+  size += snprintf(&buf[size], bufsize - size, "Cache-Control: no-cache\r\n");
+
+  /* End header */
+  size += snprintf(&buf[size], bufsize - size, "\r\n");
+
+  return size;
+}
+
 /*
  * Local Variables:
  * mode: c
diff --git a/lib/jsoninfo/src/olsrd_jsoninfo.h b/lib/jsoninfo/src/olsrd_jsoninfo.h
index 8478f62..56acb70 100644
--- a/lib/jsoninfo/src/olsrd_jsoninfo.h
+++ b/lib/jsoninfo/src/olsrd_jsoninfo.h
@@ -62,6 +62,7 @@ extern union olsr_ip_addr jsoninfo_accept_ip;
 extern union olsr_ip_addr jsoninfo_listen_ip;
 extern int ipc_port;
 extern int nompr;
+extern bool http_headers;
 
 int olsrd_plugin_interface_version(void);
 int olsrd_plugin_init(void);
diff --git a/lib/jsoninfo/src/olsrd_plugin.c b/lib/jsoninfo/src/olsrd_plugin.c
index 36550a8..03aa45f 100644
--- a/lib/jsoninfo/src/olsrd_plugin.c
+++ b/lib/jsoninfo/src/olsrd_plugin.c
@@ -64,6 +64,7 @@ union olsr_ip_addr jsoninfo_accept_ip;
 union olsr_ip_addr jsoninfo_listen_ip;
 int ipc_port;
 int nompr;
+bool http_headers;
 
 static void my_init(void) __attribute__ ((constructor));
 static void my_fini(void) __attribute__ ((destructor));
@@ -79,6 +80,7 @@ my_init(void)
 
   /* defaults for parameters */
   ipc_port = 9090;
+  http_headers = false;
   if (olsr_cnf->ip_version == AF_INET) {
     jsoninfo_accept_ip.v4.s_addr = htonl(INADDR_LOOPBACK);
     jsoninfo_listen_ip.v4.s_addr = htonl(INADDR_ANY);
@@ -120,11 +122,26 @@ store_string(const char *value, void *data, set_plugin_parameter_addon addon __a
   return 0;
 }
 
+static int
+store_boolean(const char *value, void *data, set_plugin_parameter_addon addon __attribute__ ((unused)))
+{
+  bool *dest = data;
+  if(strcmp(value, "yes") == 0)
+    *dest = true;
+  else if (strcmp(value, "no") == 0)
+    *dest = false;
+  else
+    return 1; //error
+
+  return 0;
+}
+
 static const struct olsrd_plugin_parameters plugin_parameters[] = {
   {.name = "port",.set_plugin_parameter = &set_plugin_port,.data = &ipc_port},
   {.name = "accept",.set_plugin_parameter = &set_plugin_ipaddress,.data = &jsoninfo_accept_ip},
   {.name = "listen",.set_plugin_parameter = &set_plugin_ipaddress,.data = &jsoninfo_listen_ip},
   {.name = "uuidfile",.set_plugin_parameter = &store_string,.data = uuidfile},
+  {.name = "httpheaders",.set_plugin_parameter = &store_boolean,.data = &http_headers},
 };
 
 void