Process chunked body before sending MG_EV_HTTP_MSG

mongoose.c

@@ -1,5 +1,5 @@
 // Copyright (c) 2004-2013 Sergey Lyubka
-// Copyright (c) 2013-2020 Cesanta Software Limited
+// Copyright (c) 2013-2021 Cesanta Software Limited
 // All rights reserved
 //
 // This software is dual-licensed: you can redistribute it and/or modify
@@ -15,7 +15,6 @@
 // Alternatively, you can license this software under a commercial
 // license, as set out in <https://www.cesanta.com/license>.
 
-
 #include "mongoose.h"
 
 #ifdef MG_ENABLE_LINES
@@ -1189,7 +1188,7 @@ static size_t get_chunk_length(const char *buf, size_t len, size_t *ll) {
 // an MG_EV_HTTP_CHUNK event.
 static void walkchunks(struct mg_connection *c, struct mg_http_message *hm,
                        int reqlen) {
-  size_t off = 0, ll;
+  size_t off = 0, bl, ll;
   while (off < c->recv.len - reqlen) {
     char *buf = (char *) &c->recv.buf[reqlen];
     size_t memo = c->recv.len;
@@ -1201,10 +1200,22 @@ static void walkchunks(struct mg_connection *c, struct mg_http_message *hm,
     // Increase offset only if user has not deleted this chunk
     if (memo == c->recv.len) off += cl;
     if (cl <= 5) {
-      // Zero chunk - last one. Set message length to indicate we've received
+      // Zero chunk - last one. Prepare body - cut off chunk lengths
+      off = bl = 0;
+      while (off < c->recv.len - reqlen) {
+        char *buf = (char *) &c->recv.buf[reqlen];
+        size_t memo = c->recv.len;
+        size_t cl = get_chunk_length(&buf[off], memo - reqlen - off, &ll);
+        size_t n = cl < ll + 2 ? 0 : cl - ll - 2;
+        if (cl <= 5) break;
+        memmove(buf + bl, buf + off + ll, n);
+        bl += n;
+        off += cl;
+      }
+      // Set message length to indicate we've received
       // everything, to fire MG_EV_HTTP_MSG
-      hm->message.len = off + reqlen;
+      hm->message.len = bl + reqlen;
-      hm->body.len = off;
+      hm->body.len = bl;
       break;
     }
   }

src/http.c

@@ -769,7 +769,7 @@ static size_t get_chunk_length(const char *buf, size_t len, size_t *ll) {
 // an MG_EV_HTTP_CHUNK event.
 static void walkchunks(struct mg_connection *c, struct mg_http_message *hm,
                        int reqlen) {
-  size_t off = 0, ll;
+  size_t off = 0, bl, ll;
   while (off < c->recv.len - reqlen) {
     char *buf = (char *) &c->recv.buf[reqlen];
     size_t memo = c->recv.len;
@@ -781,10 +781,22 @@ static void walkchunks(struct mg_connection *c, struct mg_http_message *hm,
     // Increase offset only if user has not deleted this chunk
     if (memo == c->recv.len) off += cl;
     if (cl <= 5) {
-      // Zero chunk - last one. Set message length to indicate we've received
+      // Zero chunk - last one. Prepare body - cut off chunk lengths
+      off = bl = 0;
+      while (off < c->recv.len - reqlen) {
+        char *buf = (char *) &c->recv.buf[reqlen];
+        size_t memo = c->recv.len;
+        size_t cl = get_chunk_length(&buf[off], memo - reqlen - off, &ll);
+        size_t n = cl < ll + 2 ? 0 : cl - ll - 2;
+        if (cl <= 5) break;
+        memmove(buf + bl, buf + off + ll, n);
+        bl += n;
+        off += cl;
+      }
+      // Set message length to indicate we've received
       // everything, to fire MG_EV_HTTP_MSG
-      hm->message.len = off + reqlen;
+      hm->message.len = bl + reqlen;
-      hm->body.len = off;
+      hm->body.len = bl;
       break;
     }
   }

test/unit_test.c

@@ -1231,7 +1231,7 @@ static void eh5(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
 
 static void test_http_chunked(void) {
   struct mg_mgr mgr;
-  const char *url = "http://127.0.0.1:12344";
+  const char *data, *url = "http://127.0.0.1:12344";
   uint32_t i, done = 0;
   mg_mgr_init(&mgr);
   mg_http_listen(&mgr, url, eh2, NULL);
@@ -1239,41 +1239,20 @@ static void test_http_chunked(void) {
   mg_http_connect(&mgr, url, eh3, &done);
   for (i = 0; i < 50 && done == 0; i++) mg_mgr_poll(&mgr, 1);
   ASSERT(i < 50);
-  {
+  data = "chunk 0chunk 1chunk 2";
-    const char *data =
+  ASSERT(done == mg_crc32(0, data, strlen(data)));
-        "7\r\nchunk 0\r\n"
-        "7\r\nchunk 1\r\n"
-        "7\r\nchunk 2\r\n"
-        "0\r\n\r\n";
-    ASSERT(done == mg_crc32(0, data, strlen(data)));
-  }
 
   done = 0;
   mg_http_connect(&mgr, url, eh4, &done);
   for (i = 0; i < 50 && done == 0; i++) mg_mgr_poll(&mgr, 1);
-  {
+  data = "chunk 0chunk 0chunk 1chunk 2chunk 0chunk 1chunk 2";
-    const char *data =
+  ASSERT(done == mg_crc32(0, data, strlen(data)));
-        "chunk 0"
-        "chunk 0"
-        "chunk 1"
-        "chunk 2"
-        "7\r\nchunk 0\r\n"
-        "7\r\nchunk 1\r\n"
-        "7\r\nchunk 2\r\n"
-        "0\r\n\r\n";
-    ASSERT(done == mg_crc32(0, data, strlen(data)));
-  }
 
   done = 0;
   mg_http_connect(&mgr, url, eh5, &done);
   for (i = 0; i < 50 && done == 0; i++) mg_mgr_poll(&mgr, 1);
-  {
+  data = "chunk 0chunk 1chunk 2";
-    const char *data =
+  ASSERT(done == mg_crc32(0, data, strlen(data)));
-        "chunk 0"
-        "chunk 1"
-        "chunk 2";
-    ASSERT(done == mg_crc32(0, data, strlen(data)));
-  }
 
   mg_mgr_free(&mgr);
   ASSERT(mgr.conns == NULL);