BUG/MEDIUM: stats: unhandled switching rules with TCP frontend
Consider the following configuration:
backend back
mode http
frontend front
mode tcp
bind localhost:8080
stats enable
stats uri /stats
tcp-request content switch-mode http if FALSE
use_backend back
Firing a request to /stats on the haproxy process started with the above
configuration will cause a segfault in http_handle_stats().
The cause for the crash is that in this case, the upgrade doesn't simply
switches to HTTP mode, but also changes the stream backend (changing from
the frontend itself to the targeted HTTP backend).
However, there is an inconsitency in the stats logic between the check
for the stats URI and the actual handling of the stats page.
Indeed, http_stats_check_uri() checks uri parameters from the proxy
undergoing the http analyzers, whereas http_handle_stats() uses s->be
instead.
During stream analysis, from the frontend perspective: s->be defaults to
the frontend. But if the frontend is in TCP mode and the stream is
upgraded to HTTP via backend switching rules, then s->be will be assigned
to the actual HTTP-capable backend in stream_set_backend().
What this means is that when the http analyzer first checks if the current
URI matches the one from the "stats uri" directive, it will check against
the "stats uri" directive from the frontend, but later since the stats
handlers reads the uri from s->be it wil actually use the value from the
backend and the previous safety checks are thus garbage, resulting in
unexpected behavior. (In our test case since the backend didn't define
"stats uri" it is set to NULL, and http_handle_stats() dereferences it)
To fix this, we should ensure that prechecks and actual stats processing
always rely on the same proxy source for stats config directives.
This is what is done in this patch, thanks to the previous commit, since
we can make sure that the stat applet will use ->http_px as its parent
proxy. So here we simply propagate the current proxy being analyzed
through all the stats processing functions.
This patch depends on:
- MINOR: stats: store the parent proxy in stats ctx (http)
It should be backported up to 2.4.
For 2.4: the fix is less trivial since stats ctx was directly stored
within the applet struct at that time, so this alternative patch must be
used instead (without "MINOR: stats: store the parent proxy in stats ctx
(http)" dependency):
diff --git a/include/haproxy/applet-t.h b/include/haproxy/applet-t.h
index
014e01ed9..
1d9a63359 100644
--- a/include/haproxy/applet-t.h
+++ b/include/haproxy/applet-t.h
@@ -121,6 +121,7 @@ struct appctx {
* keep the grouped together and avoid adding new ones.
*/
struct {
+ struct proxy *http_px; /* parent proxy of the current applet (only relevant for HTTP applet) */
void *obj1; /* context pointer used in stats dump */
void *obj2; /* context pointer used in stats dump */
uint32_t domain; /* set the stats to used, for now only proxy stats are supported */
diff --git a/src/http_ana.c b/src/http_ana.c
index
b557da89d..
1025d7711 100644
--- a/src/http_ana.c
+++ b/src/http_ana.c
@@ -63,8 +63,8 @@ static enum rule_result http_req_restrict_header_names(struct stream *s, struct
static void http_manage_client_side_cookies(struct stream *s, struct channel *req);
static void http_manage_server_side_cookies(struct stream *s, struct channel *res);
-static int http_stats_check_uri(struct stream *s, struct http_txn *txn, struct proxy *backend);
-static int http_handle_stats(struct stream *s, struct channel *req);
+static int http_stats_check_uri(struct stream *s, struct http_txn *txn, struct proxy *px);
+static int http_handle_stats(struct stream *s, struct channel *req, struct proxy *px);
static int http_handle_expect_hdr(struct stream *s, struct htx *htx, struct http_msg *msg);
static int http_reply_100_continue(struct stream *s);
@@ -428,7 +428,7 @@ int http_process_req_common(struct stream *s, struct channel *req, int an_bit, s
}
/* parse the whole stats request and extract the relevant information */
- http_handle_stats(s, req);
+ http_handle_stats(s, req, px);
verdict = http_req_get_intercept_rule(px, &px->uri_auth->http_req_rules, s);
/* not all actions implemented: deny, allow, auth */
@@ -3959,16 +3959,16 @@ void http_check_response_for_cacheability(struct stream *s, struct channel *res)
/*
* In a GET, HEAD or POST request, check if the requested URI matches the stats uri
- * for the current backend.
+ * for the current proxy.
*
* It is assumed that the request is either a HEAD, GET, or POST and that the
* uri_auth field is valid.
*
* Returns 1 if stats should be provided, otherwise 0.
*/
-static int http_stats_check_uri(struct stream *s, struct http_txn *txn, struct proxy *backend)
+static int http_stats_check_uri(struct stream *s, struct http_txn *txn, struct proxy *px)
{
- struct uri_auth *uri_auth = backend->uri_auth;
+ struct uri_auth *uri_auth = px->uri_auth;
struct htx *htx;
struct htx_sl *sl;
struct ist uri;
@@ -4003,14 +4003,14 @@ static int http_stats_check_uri(struct stream *s, struct http_txn *txn, struct p
* s->target which is supposed to already point to the stats applet. The caller
* is expected to have already assigned an appctx to the stream.
*/
-static int http_handle_stats(struct stream *s, struct channel *req)
+static int http_handle_stats(struct stream *s, struct channel *req, struct proxy *px)
{
struct stats_admin_rule *stats_admin_rule;
struct stream_interface *si = &s->si[1];
struct session *sess = s->sess;
struct http_txn *txn = s->txn;
struct http_msg *msg = &txn->req;
- struct uri_auth *uri_auth = s->be->uri_auth;
+ struct uri_auth *uri_auth = px->uri_auth;
const char *h, *lookup, *end;
struct appctx *appctx;
struct htx *htx;
@@ -4020,6 +4020,7 @@ static int http_handle_stats(struct stream *s, struct channel *req)
memset(&appctx->ctx.stats, 0, sizeof(appctx->ctx.stats));
appctx->st1 = appctx->st2 = 0;
appctx->ctx.stats.st_code = STAT_STATUS_INIT;
+ appctx->ctx.stats.http_px = px;
appctx->ctx.stats.flags |= uri_auth->flags;
appctx->ctx.stats.flags |= STAT_FMT_HTML; /* assume HTML mode by default */
if ((msg->flags & HTTP_MSGF_VER_11) && (txn->meth != HTTP_METH_HEAD))
diff --git a/src/stats.c b/src/stats.c
index
d1f3daa98..
1f0b2bff7 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -2863,9 +2863,9 @@ static int stats_dump_be_stats(struct stream_interface *si, struct proxy *px)
return stats_dump_one_line(stats, stats_count, appctx);
}
-/* Dumps the HTML table header for proxy <px> to the trash for and uses the state from
- * stream interface <si> and per-uri parameters <uri>. The caller is responsible
- * for clearing the trash if needed.
+/* Dumps the HTML table header for proxy <px> to the trash and uses the state from
+ * stream interface <si>. The caller is responsible for clearing the trash if
+ * needed.
*/
static void stats_dump_html_px_hdr(struct stream_interface *si, struct proxy *px)
{
@@ -3015,17 +3015,19 @@ static void stats_dump_html_px_end(struct stream_interface *si, struct proxy *px
* input buffer. Returns 0 if it had to stop dumping data because of lack of
* buffer space, or non-zero if everything completed. This function is used
* both by the CLI and the HTTP entry points, and is able to dump the output
- * in HTML or CSV formats. If the later, <uri> must be NULL.
+ * in HTML or CSV formats.
*/
int stats_dump_proxy_to_buffer(struct stream_interface *si, struct htx *htx,
- struct proxy *px, struct uri_auth *uri)
+ struct proxy *px)
{
struct appctx *appctx = __objt_appctx(si->end);
- struct stream *s = si_strm(si);
struct channel *rep = si_ic(si);
struct server *sv, *svs; /* server and server-state, server-state=server or server->track */
struct listener *l;
+ struct uri_auth *uri = NULL;
+ if (appctx->ctx.stats.http_px)
+ uri = appctx->ctx.stats.http_px->uri_auth;
chunk_reset(&trash);
switch (appctx->ctx.stats.px_st) {
@@ -3045,7 +3047,7 @@ int stats_dump_proxy_to_buffer(struct stream_interface *si, struct htx *htx,
break;
/* match '.' which means 'self' proxy */
- if (strcmp(scope->px_id, ".") == 0 && px == s->be)
+ if (strcmp(scope->px_id, ".") == 0 && px == appctx->ctx.stats.http_px)
break;
scope = scope->next;
}
@@ -3227,10 +3229,16 @@ int stats_dump_proxy_to_buffer(struct stream_interface *si, struct htx *htx,
}
/* Dumps the HTTP stats head block to the trash for and uses the per-uri
- * parameters <uri>. The caller is responsible for clearing the trash if needed.
+ * parameters from the parent proxy. The caller is responsible for clearing
+ * the trash if needed.
*/
-static void stats_dump_html_head(struct appctx *appctx, struct uri_auth *uri)
+static void stats_dump_html_head(struct appctx *appctx)
{
+ struct uri_auth *uri;
+
+ BUG_ON(!appctx->ctx.stats.http_px);
+ uri = appctx->ctx.stats.http_px->uri_auth;
+
/* WARNING! This must fit in the first buffer !!! */
chunk_appendf(&trash,
"<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\"\n"
@@ -3345,17 +3353,21 @@ static void stats_dump_html_head(struct appctx *appctx, struct uri_auth *uri)
}
/* Dumps the HTML stats information block to the trash for and uses the state from
- * stream interface <si> and per-uri parameters <uri>. The caller is responsible
- * for clearing the trash if needed.
+ * stream interface <si> and per-uri parameters from the parent proxy. The caller
+ * is responsible for clearing the trash if needed.
*/
-static void stats_dump_html_info(struct stream_interface *si, struct uri_auth *uri)
+static void stats_dump_html_info(struct stream_interface *si)
{
struct appctx *appctx = __objt_appctx(si->end);
unsigned int up = (now.tv_sec - start_date.tv_sec);
char scope_txt[STAT_SCOPE_TXT_MAXLEN + sizeof STAT_SCOPE_PATTERN];
const char *scope_ptr = stats_scope_ptr(appctx, si);
+ struct uri_auth *uri;
unsigned long long bps = (unsigned long long)read_freq_ctr(&global.out_32bps) * 32;
+ BUG_ON(!appctx->ctx.stats.http_px);
+ uri = appctx->ctx.stats.http_px->uri_auth;
+
/* Turn the bytes per second to bits per second and take care of the
* usual ethernet overhead in order to help figure how far we are from
* interface saturation since it's the only case which usually matters.
@@ -3629,8 +3641,7 @@ static void stats_dump_json_end()
* a pointer to the current server/listener.
*/
static int stats_dump_proxies(struct stream_interface *si,
- struct htx *htx,
- struct uri_auth *uri)
+ struct htx *htx)
{
struct appctx *appctx = __objt_appctx(si->end);
struct channel *rep = si_ic(si);
@@ -3650,7 +3661,7 @@ static int stats_dump_proxies(struct stream_interface *si,
px = appctx->ctx.stats.obj1;
/* skip the disabled proxies, global frontend and non-networked ones */
if (!px->disabled && px->uuid > 0 && (px->cap & (PR_CAP_FE | PR_CAP_BE))) {
- if (stats_dump_proxy_to_buffer(si, htx, px, uri) == 0)
+ if (stats_dump_proxy_to_buffer(si, htx, px) == 0)
return 0;
}
@@ -3666,14 +3677,12 @@ static int stats_dump_proxies(struct stream_interface *si,
}
/* This function dumps statistics onto the stream interface's read buffer in
- * either CSV or HTML format. <uri> contains some HTML-specific parameters that
- * are ignored for CSV format (hence <uri> may be NULL there). It returns 0 if
- * it had to stop writing data and an I/O is needed, 1 if the dump is finished
- * and the stream must be closed, or -1 in case of any error. This function is
- * used by both the CLI and the HTTP handlers.
+ * either CSV or HTML format. It returns 0 if it had to stop writing data and
+ * an I/O is needed, 1 if the dump is finished and the stream must be closed,
+ * or -1 in case of any error. This function is used by both the CLI and the
+ * HTTP handlers.
*/
-static int stats_dump_stat_to_buffer(struct stream_interface *si, struct htx *htx,
- struct uri_auth *uri)
+static int stats_dump_stat_to_buffer(struct stream_interface *si, struct htx *htx)
{
struct appctx *appctx = __objt_appctx(si->end);
struct channel *rep = si_ic(si);
@@ -3688,7 +3697,7 @@ static int stats_dump_stat_to_buffer(struct stream_interface *si, struct htx *ht
case STAT_ST_HEAD:
if (appctx->ctx.stats.flags & STAT_FMT_HTML)
- stats_dump_html_head(appctx, uri);
+ stats_dump_html_head(appctx);
else if (appctx->ctx.stats.flags & STAT_JSON_SCHM)
stats_dump_json_schema(&trash);
else if (appctx->ctx.stats.flags & STAT_FMT_JSON)
@@ -3708,7 +3717,7 @@ static int stats_dump_stat_to_buffer(struct stream_interface *si, struct htx *ht
case STAT_ST_INFO:
if (appctx->ctx.stats.flags & STAT_FMT_HTML) {
- stats_dump_html_info(si, uri);
+ stats_dump_html_info(si);
if (!stats_putchk(rep, htx, &trash))
goto full;
}
@@ -3733,7 +3742,7 @@ static int stats_dump_stat_to_buffer(struct stream_interface *si, struct htx *ht
case STATS_DOMAIN_PROXY:
default:
/* dump proxies */
- if (!stats_dump_proxies(si, htx, uri))
+ if (!stats_dump_proxies(si, htx))
return 0;
break;
}
@@ -4112,11 +4121,14 @@ static int stats_process_http_post(struct stream_interface *si)
static int stats_send_http_headers(struct stream_interface *si, struct htx *htx)
{
struct stream *s = si_strm(si);
- struct uri_auth *uri = s->be->uri_auth;
+ struct uri_auth *uri;
struct appctx *appctx = __objt_appctx(si->end);
struct htx_sl *sl;
unsigned int flags;
+ BUG_ON(!appctx->ctx.stats.http_px);
+ uri = appctx->ctx.stats.http_px->uri_auth;
+
flags = (HTX_SL_F_IS_RESP|HTX_SL_F_VER_11|HTX_SL_F_XFER_ENC|HTX_SL_F_XFER_LEN|HTX_SL_F_CHNK);
sl = htx_add_stline(htx, HTX_BLK_RES_SL, flags, ist("HTTP/1.1"), ist("200"), ist("OK"));
if (!sl)
@@ -4166,11 +4178,14 @@ static int stats_send_http_redirect(struct stream_interface *si, struct htx *htx
{
char scope_txt[STAT_SCOPE_TXT_MAXLEN + sizeof STAT_SCOPE_PATTERN];
struct stream *s = si_strm(si);
- struct uri_auth *uri = s->be->uri_auth;
+ struct uri_auth *uri;
struct appctx *appctx = __objt_appctx(si->end);
struct htx_sl *sl;
unsigned int flags;
+ BUG_ON(!appctx->ctx.stats.http_px);
+ uri = appctx->ctx.stats.http_px->uri_auth;
+
/* scope_txt = search pattern + search query, appctx->ctx.stats.scope_len is always <= STAT_SCOPE_TXT_MAXLEN */
scope_txt[0] = 0;
if (appctx->ctx.stats.scope_len) {
@@ -4263,7 +4278,7 @@ static void http_stats_io_handler(struct appctx *appctx)
}
if (appctx->st0 == STAT_HTTP_DUMP) {
- if (stats_dump_stat_to_buffer(si, res_htx, s->be->uri_auth))
+ if (stats_dump_stat_to_buffer(si, res_htx))
appctx->st0 = STAT_HTTP_DONE;
}
@@ -4888,6 +4903,7 @@ static int cli_parse_show_stat(char **args, char *payload, struct appctx *appctx
appctx->ctx.stats.scope_str = 0;
appctx->ctx.stats.scope_len = 0;
+ appctx->ctx.stats.http_px = NULL; // not under http context
appctx->ctx.stats.flags = STAT_SHNODE | STAT_SHDESC;
if ((strm_li(si_strm(appctx->owner))->bind_conf->level & ACCESS_LVL_MASK) >= ACCESS_LVL_OPER)
@@ -4954,7 +4970,7 @@ static int cli_io_handler_dump_info(struct appctx *appctx)
*/
static int cli_io_handler_dump_stat(struct appctx *appctx)
{
- return stats_dump_stat_to_buffer(appctx->owner, NULL, NULL);
+ return stats_dump_stat_to_buffer(appctx->owner, NULL);
}
static int cli_io_handler_dump_json_schema(struct appctx *appctx)
projects / haproxy-3.0.git / commit