[PATCH] Fixed checking for no port in the upstream block references

[Valentin V. Bartenev]

# HG changeset patch
# User Valentin Bartenev <vbart at wbsrv.ru>
# Date 1718475780 -10800
#      Sat Jun 15 21:23:00 2024 +0300
# Node ID 6cda0d648e42c173e9eb2de5b5baab6a2d34595b
# Parent  02e9411009b987f408214ab4a8b6b6093f843bcd
Fixed checking for no port in the upstream block references.

A configurations like this one:

   server {
       proxy_pass backend:80;
   }

   server {
       proxy_pass backend;
   }

   upstream backend {
       server 127.0.0.1:443;
   }

is rejected, since a "proxy_pass" refence of the upstream block cannot have
a port specified.  But if the "proxy_pass" directive with no port appeared
first then the check for no port didn't work properly and such configurations
were allowed:

   server {
       proxy_pass backend;
   }

   server {
       proxy_pass backend:80;
   }

   upstream backend {
       server 127.0.0.1:443;
   }

So, the fix is to continue lookup for all upstreams in the list checking
for duplicate references with port specified.

The issue was present in both "stream" and "http" modules.  And in case of
there assumes port 80 (or 443 for https) by default.  For example, in the
config below:

   server {
       location / {
           proxy_pass http://backend;
       }
   }

   server {
       location / {
           proxy_pass http://backend:80;
       }
   }

   upstream backend {
       server 127.0.0.1:8000;
   }

the second "proxy_pass" is aggregated with the first one, but the "no_port"
flag was left intact.  In order, to properly detect such cases now the flag
is reset at the first case of reference with an explicit port set and also
the position of such reference is stored for a proper error handling.

diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -6341,6 +6341,7 @@ ngx_http_upstream_add(ngx_conf_t *cf, ng
      umcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_upstream_module);
  
      uscfp = umcf->upstreams.elts;
+    uscf = NULL;
  
      for (i = 0; i < umcf->upstreams.nelts; i++) {
  
@@ -6383,11 +6384,23 @@ ngx_http_upstream_add(ngx_conf_t *cf, ng
          if (flags & NGX_HTTP_UPSTREAM_CREATE) {
              uscfp[i]->flags = flags;
              uscfp[i]->port = 0;
+            uscf = uscfp[i];
+            continue;
+        }
+
+        if (uscfp[i]->no_port && !u->no_port) {
+            uscfp[i]->no_port = 0;
+            uscfp[i]->file_name = cf->conf_file->file.name.data;
+            uscfp[i]->line = cf->conf_file->line;
          }
  
          return uscfp[i];
      }
  
+    if (uscf) {
+        return uscf;
+    }
+
      uscf = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_srv_conf_t));
      if (uscf == NULL) {
          return NULL;
diff --git a/src/stream/ngx_stream_upstream.c b/src/stream/ngx_stream_upstream.c
--- a/src/stream/ngx_stream_upstream.c
+++ b/src/stream/ngx_stream_upstream.c
@@ -583,6 +583,7 @@ ngx_stream_upstream_add(ngx_conf_t *cf,
      umcf = ngx_stream_conf_get_module_main_conf(cf, ngx_stream_upstream_module);
  
      uscfp = umcf->upstreams.elts;
+    uscf = NULL;
  
      for (i = 0; i < umcf->upstreams.nelts; i++) {
  
@@ -622,11 +623,17 @@ ngx_stream_upstream_add(ngx_conf_t *cf,
  
          if (flags & NGX_STREAM_UPSTREAM_CREATE) {
              uscfp[i]->flags = flags;
+            uscf = uscfp[i];
+            continue;
          }
  
          return uscfp[i];
      }
  
+    if (uscf) {
+        return uscf;
+    }
+
      uscf = ngx_pcalloc(cf->pool, sizeof(ngx_stream_upstream_srv_conf_t));
      if (uscf == NULL) {
          return NULL;