fix get_request_entity()

get_request_entity()'s purpose is to drain remaining unread bytes
in the request read pipe before handing out an error page,
and kinda surprisingly, also when connection to the stathost is
done.

in the stathost case tinyproxy just skipped proper processing and
jumped to the error handler code, and remembering whether a
connection to the stathost was desired in a variable, then doing
things a bit differently depending on whether it's set.

i tried to fix issues with get_request_entity in
88153e944f7d28f57cccc77f3228a3f54f78ce4e (which is basically the
right fix for the issue it tried to solve, but incomplete),
and resulting from there in 78cc5b72b18a3c0d196126bfbc5d3b6473386da9.
the latter fix wasn't quite right since we're not supposed to check
whether the socket is ready for writing, and having a return value
of 2 instead of 1 got resulted in some of the if statements not
kicking in when they should have.
this also resulted in the stathost page no longer working.

after in-depth study of the issue i realized that we only need to
call get_request_entity() when the headers aren't completely read,
additional to setting the proper connection timeout as
88153e944f7d28f57cccc77f3228a3f54f78ce4e already implemented.
the changes of 78cc5b72b18a3c0d196126bfbc5d3b6473386da9 have been
reverted.

1 files changed, 11 insertions, 8 deletions

diff --git a/src/reqs.c b/src/reqs.c
index 514bc21..e3c59c1 100644
--- a/src/reqs.c
+++ b/src/reqs.c
@@ -1439,19 +1439,21 @@ connect_to_upstream (struct conn_s *connptr, struct request_s *request)
 #endif
 }
 
+/* this function "drains" remaining bytes in the read pipe from
+   the client. it's usually only called on error before displaying
+   an error code/page. */
 static int
 get_request_entity(struct conn_s *connptr)
 {
         int ret;
-        fd_set rset, wset;
+        fd_set rset;
         struct timeval tv;
 
         FD_ZERO (&rset);
         FD_SET (connptr->client_fd, &rset);
-        memcpy(&wset, &rset, sizeof wset);
         tv.tv_sec = config->idletimeout;
         tv.tv_usec = 0;
-        ret = select (connptr->client_fd + 1, &rset, &wset, NULL, &tv);
+        ret = select (connptr->client_fd + 1, &rset, NULL, NULL, &tv);
 
         if (ret == -1) {
                 log_message (LOG_ERR,
@@ -1473,8 +1475,6 @@ get_request_entity(struct conn_s *connptr)
                                      nread);
                         ret = 0;
                 }
-        } else if (ret == 1 && FD_ISSET (connptr->client_fd, &wset) && connptr->connect_method) {
-               ret = 0;
         } else {
                 log_message (LOG_ERR, "strange situation after select: "
                              "ret = %d, but client_fd (%d) is not readable...",
@@ -1485,7 +1485,7 @@ get_request_entity(struct conn_s *connptr)
         return ret;
 }
 
-static void handle_connection_failure(struct conn_s *connptr)
+static void handle_connection_failure(struct conn_s *connptr, int got_headers)
 {
         /*
          * First, get the body if there is one.
@@ -1493,7 +1493,7 @@ static void handle_connection_failure(struct conn_s *connptr)
          * it is still marked for reading and we won't be able
          * to send our data properly.
          */
-        if (get_request_entity (connptr) < 0) {
+        if (!got_headers && get_request_entity (connptr) < 0) {
                 log_message (LOG_WARNING,
                              "Could not retrieve request entity");
                 indicate_http_error (connptr, 400, "Bad Request",
@@ -1524,8 +1524,10 @@ void handle_connection (int fd, union sockaddr_union* addr)
 {
 
 #define HC_FAIL() \
-        do {handle_connection_failure(connptr); goto done;} while(0)
+        do {handle_connection_failure(connptr, got_headers); goto done;} \
+        while(0)
 
+        int got_headers = 0;
         ssize_t i;
         struct conn_s *connptr;
         struct request_s *request = NULL;
@@ -1619,6 +1621,7 @@ void handle_connection (int fd, union sockaddr_union* addr)
                 update_stats (STAT_BADCONN);
                 HC_FAIL();
         }
+        got_headers = 1;
 
         if (config->basicauth_list != NULL) {
                 ssize_t len;