BUG/MEDIUM: applet: Fix applet API to put input data in a buffer

applet_putblk and co were added to simplify applets. In 2.8, a fix was
pushed to deal with all errors as a room error because the vast majority of
applets didn't expect other kind of errors. The API was changed with the
commit 389b7d1f7b ("BUG/MEDIUM: applet: Fix API for function to push new
data in channels buffer").

Unfortunately and for unknown reason, the fix was totally failed. Checks on
channel functions were just wrong and not consistent. applet_putblk()
function is especially affected because the error is returned but no flag
are set on the SC to request more room. Because of this bug, applets relying
on it may be blocked, waiting for more room, and never woken up.

It is an issue for the peer and spoe applets.

This patch must be backported as far as 2.8.

diff --git a/include/haproxy/applet.h b/include/haproxy/applet.h
index b76c027e9a924d56ede5c797f399ebe806c699ae..8d9f49aec3659bc4238c3aa4bfbe67473253b2cb 100644 (file)
--- a/include/haproxy/applet.h
+++ b/include/haproxy/applet.h
@@ -325,7 +325,7 @@ static inline int applet_putblk(struct appctx *appctx, const char *blk, int len)
                struct sedesc *se = appctx->sedesc;
 
                ret = ci_putblk(sc_ic(se->sc), blk, len);
-               if (ret < -1) {
+               if (ret < 0) {
                        /* XXX: Handle all errors as a lack of space because callers
                         * don't handles other cases for now. So applets must be
                         * careful to handles shutdown (-2) and invalid calls (-3) by
@@ -362,7 +362,7 @@ static inline int applet_putstr(struct appctx *appctx, const char *str)
                struct sedesc *se = appctx->sedesc;
 
                ret = ci_putstr(sc_ic(se->sc), str);
-               if (ret == -1) {
+               if (ret < 0) {
                        /* XXX: Handle all errors as a lack of space because callers
                         * don't handles other cases for now. So applets must be
                         * careful to handles shutdown (-2) and invalid calls (-3) by
@@ -397,7 +397,7 @@ static inline int applet_putchr(struct appctx *appctx, char chr)
                struct sedesc *se = appctx->sedesc;
 
                ret = ci_putchr(sc_ic(se->sc), chr);
-               if (ret == -1) {
+               if (ret < 0) {
                        /* XXX: Handle all errors as a lack of space because callers
                         * don't handles other cases for now. So applets must be
                         * careful to handles shutdown (-2) and invalid calls (-3) by