websrv_ssp_redux.patch

--- original.c	2017-01-17 17:17:43.805314775 -0800
+++ websrv.c	2017-01-17 16:50:16.189912144 -0800
@@ -103,6 +103,40 @@
     return 200;
 }
 
+static void* get_range_header(char* req, size_t reqlen)
+{
+        const char *s = "\r\nRange: bytes=";
+        return memmem(req, reqlen, s, strlen(s));
+}
+
+static int get_ranges_from_header(char *request, unsigned long *start , unsigned long *end)
+{
+        char *req = request+strlen("\r\nRange: bytes=");
+        char *c, _c;
+        char *tmp;
+
+        for(c=req; *c!='\r' && *c!='\n' && *c!='-' && *c!=' ' && *c!='\0'; c++);
+        if (*c!='-')
+                return -1;
+
+        // get beginning of range
+        _c = *c;
+        *c = '\0';
+        tmp = strdupa(req);
+        *start = strtoul(tmp, NULL, 10);
+        *c = _c;
+
+        // get end of range
+        req = ++c;
+        for(c=req; *c!='\r' && *c!='\n' && *c!=' ' && *c!='\0'; c++);
+        _c = *c;
+        *c = '\0';
+        tmp = strdupa(req);
+        *end = strtoul(tmp, NULL, 10);
+        *c = _c;
+        return 0;
+}
+
 int handle_req(int socket, char* request, size_t len)
 {
     FILE* f;
@@ -142,7 +176,33 @@
         return send_error(socket, 404, "Not Found");
     fseek(f, 0, SEEK_END);
     fsize = ftell(f);
-    fseek(f, 0, 0);
+    fseek(f, 0, SEEK_SET);
+
+    /*
+     * Follow HTTP Range header directive if provided
+     */
+    unsigned long start, end;
+    char *ptr;
+    int r;
+
+    start = end = 0;
+    ptr = get_range_header(request, len);
+    if (ptr){
+            if(get_ranges_from_header(ptr, &start, &end)==0){
+                    if (start && end){
+                            printf("%s:%d reading range of file '%s' from %u-%u\n", inet_ntoa(client.sin_addr), htons(client.sin_port), file, start, end);
+                            if (lseek(fileno(f), start, SEEK_SET)==-1){
+                                    perror("lseek() failed:");
+                            } else {
+                                    fsize = end - start;
+                            }
+                    }
+            }
+    }
+
+    if (fsize==0){
+            fsize=0x8000;
+    }
 
     /*
      * Send header
@@ -156,6 +216,8 @@
      */
     while ((len = fread(buf, 1, sizeof(buf), f)) > 0) {
         send(socket, buf, len, 0);
+        if(--fsize <= 0)
+                break;
     }
 
     fclose(f);