Commit cd85eac0 authored by Nick Mathewson's avatar Nick Mathewson 🥔
Browse files

r17433@catbus: nickm | 2007-12-29 12:35:57 -0500 

 Incomplete code to avoid doing needless pull-ups on HTTP.  Also, use memstr instead of strstr to find the content-length header.


svn:r13005
parent f4f5dc4a

src/or/buffers.c

+110 −2
Original line number Diff line number Diff line
@@ -943,6 +943,93 @@ move_buf_to_buf(buf_t *buf_out, buf_t *buf_in, size_t *buf_flushlen) 
  return cp;

}



// #define BUFPOS

#ifdef BUFPOS

typedef struct buf_pos_t {

  chunk_t *chunk;

  int pos;

  int pos_absolute;

};



static void

buf_pos_init(buf_t *buf, buf_pos_t *out)

{

  out->chunk = buf->head;

  out->pos = 0;

  out->pos_absolute = 0;

}



static int

buf_find_pos_of_char(const buf_t *buf, char ch, buf_pos_t *out)

{

  chunk_t *chunk;

  int offset = 0;

  int pos = chunk->pos;

  for (chunk = out->chunk; chunk; chunk = chunk->next) {

    char *cp = memchr(chunk->data+pos, ch, chunk->datalen-pos);

    if (cp) {

      out->chunk = chunk;

      out->pos = cp - chunk->data;

      out->pos_absolute = offset + (cp - chunk->data);

      return out->pos_absolute;

    } else {

      offset += chunk->datalen;

      pos = 0;

    }

  }

  return -1;

}



static INLINE int

buf_pos_inc(buf_pos_t *pos)

{

  if (pos->pos == pos->chunk->datalen) {

    if (!pos->chunk->next)

      return -1;

    pos->chunk = pos->chunk->next;

    pos->pos = 0;

  } else {

    ++pos->pos;

  }

  ++pos->pos_absolute;

}



static int

buf_matches_at_pos(const buf_t *buf, const buf_pos_t *pos, const char *s,

                   int n)

{

  buf_pos_t p;

  memcpy(p, pos, sizeof(p));



  while (n) {

    char ch = p->chunk->data[p->pos];

    if (ch != *s)

      return 0;

    ++s;

    --n;

    if (buf_pos_inc(p)<0)

      return 0;

  }

  return 1;

}



static int

buf_find_string_offset(const char *buf, const char *s, int n)

{

  buf_pos_t pos;

  buf_pos_init(buf, &pos);

  while (buf_find_pos_of_char(buf, *s, &pos) >= 0) {

    if (buf_matches_at_pos(buf, pos, s, n)) {

      return pos->pos_absolute;

    } else {

      if (buf_pos_inc(pos)<0)

        return -1;

    }

  }

  return -1;

}

#endif



/** There is a (possibly incomplete) http statement on <b>buf</b>, of the

 * form "\%s\\r\\n\\r\\n\%s", headers, body. (body may contain nuls.)

 * If a) the headers include a Content-Length field and all bytes in
@@ -968,14 +1055,33 @@ fetch_from_buf_http(buf_t *buf, 
                    char **body_out, size_t *body_used, size_t max_bodylen,

                    int force_complete)

{

  char *headers, *body, *p;

  char *headers, *p, *body;

  size_t headerlen, bodylen, contentlen;

#ifdef BUFPOS

  int crlf_offset;

#endif



  check();

  if (!buf->head)

    return 0;



  headers = buf->head->data;



#ifdef BUFPOS

  crlf_offset = buf_find_string_offset(buf, "\r\n\r\n", 4);

  if (crlf_offset > max_headerlen ||

      (crlf_offset < 0 && buf->datalen > max_headerlen)) {

    log_debug(LD_HTTP,"headers too long.");

    return -1;

  } else if (crlf_offset < 0) {

    log_debug(LD_HTTP,"headers not all here yet.");

    return 0;

  }

  if (buf->head->datalen < crlf_offset + 4)

    buf_pullup(buf, crlf_offset+4, 0);

  headerlen = crlf_offset + 4;

  body = buf->data + headerlen; /*XXX020 unused. */

#else

  /* See if CRLFCRLF is already in the head chunk.  If it is, we don't need

   * to move or resize anything. */

  body = (char*) tor_memmem(buf->head->data, buf->head->datalen,
@@ -1001,6 +1107,8 @@ fetch_from_buf_http(buf_t *buf, 
  }

  body += 4; /* Skip the the CRLFCRLF */

  headerlen = body-headers; /* includes the CRLFCRLF */

#endif



  bodylen = buf->datalen - headerlen;

  log_debug(LD_HTTP,"headerlen %d, bodylen %d.", (int)headerlen, (int)bodylen);
@@ -1016,7 +1124,7 @@ fetch_from_buf_http(buf_t *buf, 
  }



#define CONTENT_LENGTH "\r\nContent-Length: "

  p = strstr(headers, CONTENT_LENGTH);

  p = (char*) tor_memstr(headers, headerlen, CONTENT_LENGTH);

  if (p) {

    int i;

    i = atoi(p+strlen(CONTENT_LENGTH));