httpd: fix offset for sendfile

If the Range: header is not present it the request,
the offset passed to sendfile is wrong,
and httpd falls back to the read-write loop.

function                                             old     new   delta
send_file_and_exit                                   857     865      +8
handle_incoming_and_exit                            2239    2230      -9
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 8/-9)               Total: -1 bytes

Signed-off-by: Maxim Storchak <m.storchak@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/networking/httpd.c b/networking/httpd.c
index 4346141ee..4c014bc71 100644
--- a/networking/httpd.c
+++ b/networking/httpd.c
@@ -1871,7 +1871,7 @@ static NOINLINE void send_file_and_exit(const char *url, int what)
                 send_headers(HTTP_OK);
 #if ENABLE_FEATURE_USE_SENDFILE
         {
-                off_t offset = range_start;
+                off_t offset = (range_start < 0) ? 0 : range_start;
                 while (1) {
                         /* sz is rounded down to 64k */
                         ssize_t sz = MAXINT(ssize_t) - 0xffff;
@@ -2486,8 +2486,8 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
                 if (STRNCASECMP(iobuf, "Range:") == 0) {
                         /* We know only bytes=NNN-[MMM] */
                         char *s = skip_whitespace(iobuf + sizeof("Range:")-1);
-                        if (is_prefixed_with(s, "bytes=")) {
-                                s += sizeof("bytes=")-1;
+                        s = is_prefixed_with(s, "bytes=");
+                        if (s) {
                                 range_start = BB_STRTOOFF(s, &s, 10);
                                 if (s[0] != '-' || range_start < 0) {
                                         range_start = -1;