BUG/MEDIUM: dns: Properly handle error when a response consumed
When a response is consumed, result for co_getblk() is never checked. It
seems ok because amount of output data is always checked first. But There is
an issue when we try to get the first 2 bytes to read the message length. If
there is only one byte followed by a shutdown, the applet ignore the
shutdown and loop till the timeout to get more data.
So to avoid any issue and improve shutdown detection, the co_getblk() return
value is always tested. In addition, if there is not enough data, the applet
explicitly ask for more data by calling applet_need_more_data().
This patch relies on the previous one:
* BUG/MEDIUM: channel: Improve reports for shut in co_getblk()
Both should be backported as far as 2.4. On 2.5 and 2.4,
applet_need_more_data() must be replaced by si_rx_endp_more().
(cherry picked from commit 28975e1e1012e4a009b4208f3fc022ea2bfb8b82)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit dc608287aedf7fe65a49fca27d933882790513c5)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 10a19f1841d759732ce59a7e64770fa887049b54)
[cf: In fact applet_need_more_data() must be replaced by si_cant_get()]
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit fad221e24604a68d17044f7c4ca3d95143a722f6)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/src/dns.c b/src/dns.c
index c4b2af0..3277f40 100644
--- a/src/dns.c
+++ b/src/dns.c
@@ -656,30 +656,35 @@
struct dns_query *query;
if (!ds->rx_msg.len) {
- /* next message len is not fully available into the channel */
- if (co_data(si_oc(si)) < 2)
- break;
-
/* retrieve message len */
- co_getblk(si_oc(si), (char *)&msg_len, 2, 0);
+ ret = co_getblk(si_oc(si), (char *)&msg_len, 2, 0);
+ if (ret <= 0) {
+ if (ret == -1)
+ goto close;
+ si_cant_get(si);
+ break;
+ }
/* mark as consumed */
co_skip(si_oc(si), 2);
/* store message len */
ds->rx_msg.len = ntohs(msg_len);
+ if (!ds->rx_msg.len)
+ continue;
}
- if (!co_data(si_oc(si))) {
- /* we need more data but nothing is available */
- break;
- }
-
if (co_data(si_oc(si)) + ds->rx_msg.offset < ds->rx_msg.len) {
/* message only partially available */
/* read available data */
- co_getblk(si_oc(si), ds->rx_msg.area + ds->rx_msg.offset, co_data(si_oc(si)), 0);
+ ret = co_getblk(si_oc(si), ds->rx_msg.area + ds->rx_msg.offset, co_data(si_oc(si)), 0);
+ if (ret <= 0) {
+ if (ret == -1)
+ goto close;
+ si_cant_get(si);
+ break;
+ }
/* update message offset */
ds->rx_msg.offset += co_data(si_oc(si));
@@ -688,13 +693,20 @@
co_skip(si_oc(si), co_data(si_oc(si)));
/* we need to wait for more data */
+ si_cant_get(si);
break;
}
/* enough data is available into the channel to read the message until the end */
/* read from the channel until the end of the message */
- co_getblk(si_oc(si), ds->rx_msg.area + ds->rx_msg.offset, ds->rx_msg.len - ds->rx_msg.offset, 0);
+ ret = co_getblk(si_oc(si), ds->rx_msg.area + ds->rx_msg.offset, ds->rx_msg.len - ds->rx_msg.offset, 0);
+ if (ret <= 0) {
+ if (ret == -1)
+ goto close;
+ si_cant_get(si);
+ break;
+ }
/* consume all data until the end of the message from the channel */
co_skip(si_oc(si), ds->rx_msg.len - ds->rx_msg.offset);