dnsmasq/dnsmasq-2.79-server-domain-rh1919894.patch

From 5747d7b3dffdcd45d4410bb380e466818734cb27 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Petr=20Men=C5=A1=C3=ADk?= <pemensik@redhat.com>
Date: Mon, 19 Apr 2021 13:56:23 +0200
Subject: [PATCH] Use load-balancing also for --server=/domains/

Do not (yet) move servers to server_domain structure. Instead use
separate server_domains to store just last_server and requests count and
time.

Introduces domain information duplicity, but minimizes required changes
to daemon->servers usage.

Optimize server domain record

Set pointer to domain record when struct server is created. When
searching for domain pointer, use this pointer to make it quick.
---
 src/dnsmasq.h |  18 +++++++--
 src/forward.c |  52 ++++++++++++++++----------
 src/network.c | 101 ++++++++++++++++++++++++++++++++++++++++++++++----
 src/option.c  |   5 +++
 4 files changed, 146 insertions(+), 30 deletions(-)

diff --git a/src/dnsmasq.h b/src/dnsmasq.h
index 1e21005..b6dcc50 100644
--- a/src/dnsmasq.h
+++ b/src/dnsmasq.h
@@ -559,6 +559,17 @@ struct randfd_list {
   struct randfd_list *next;
 };
 
+/* contains domain specific set of servers.
+ * If domain is NULL, just normal servers. */
+struct server_domain {
+  char *domain;
+  struct server *last_server;
+  time_t forwardtime;
+  int forwardcount;
+  unsigned int flags; /* server.flags alternative */
+  struct server_domain *next;
+};
+
 struct server {
   union mysockaddr addr, source_addr;
   char interface[IF_NAMESIZE+1];
@@ -571,6 +582,7 @@ struct server {
 #ifdef HAVE_LOOP
   u32 uid;
 #endif
+  struct server_domain *serv_domain;
   struct server *next; 
 };
 
@@ -1053,6 +1065,7 @@ extern struct daemon {
   struct iname *if_names, *if_addrs, *if_except, *dhcp_except, *auth_peers, *tftp_interfaces;
   struct bogus_addr *bogus_addr, *ignore_addr;
   struct server *servers;
+  struct server_domain *server_domains;
   struct ipsets *ipsets;
   int log_fac; /* log facility */
   char *log_file; /* optional log file */
@@ -1121,9 +1134,6 @@ extern struct daemon {
   struct serverfd *sfds;
   struct irec *interfaces;
   struct listener *listeners;
-  struct server *last_server;
-  time_t forwardtime;
-  int forwardcount;
   struct server *srv_save; /* Used for resend on DoD */
   size_t packet_len;       /*      "        "        */
   int    fd_save;          /*      "        "        */
@@ -1394,6 +1404,8 @@ int label_exception(int index, int family, union all_addr *addr);
 int fix_fd(int fd);
 int tcp_interface(int fd, int af);
 int set_ipv6pktinfo(int fd);
+struct server_domain *server_domain_find_domain(const char *domain);
+struct server_domain *server_domain_new(struct server *serv);
 #ifdef HAVE_DHCP6
 void join_multicast(int dienow);
 #endif
diff --git a/src/forward.c b/src/forward.c
index 9322b6a..b09dc96 100644
--- a/src/forward.c
+++ b/src/forward.c
@@ -107,7 +107,8 @@ int send_from(int fd, int nowild, char *packet, size_t len,
 }
           
 static unsigned int search_servers(time_t now, union all_addr **addrpp, unsigned int qtype,
-				   char *qdomain, int *type, char **domain, int *norebind)
+				   char *qdomain, int *type, char **domain, int *norebind,
+				   struct server_domain **serv_domain)
 			      
 {
   /* If the query ends in the domain in one of our servers, set
@@ -120,6 +121,9 @@ static unsigned int search_servers(time_t now, union all_addr **addrpp, unsigned
   unsigned int flags = 0;
   static union all_addr zero;
   
+  if (serv_domain)
+    *serv_domain = NULL;
+
   for (serv = daemon->servers; serv; serv=serv->next)
     if (qtype == F_DNSSECOK && !(serv->flags & SERV_DO_DNSSEC))
       continue;
@@ -187,6 +191,8 @@ static unsigned int search_servers(time_t now, union all_addr **addrpp, unsigned
 		  {
 		    *type = serv->flags & (SERV_HAS_DOMAIN | SERV_USE_RESOLV | SERV_NO_REBIND | SERV_DO_DNSSEC);
 		    *domain = serv->domain;
+		    if (serv_domain)
+		      *serv_domain = serv->serv_domain;
 		    matchlen = domainlen;
 		    if (serv->flags & SERV_NO_ADDR)
 		      flags = F_NXDOMAIN;
@@ -243,6 +249,8 @@ static unsigned int search_servers(time_t now, union all_addr **addrpp, unsigned
       *type = 0; /* use normal servers for this domain */
       *domain = NULL;
     }
+  if (serv_domain && !*serv_domain)
+    *serv_domain = server_domain_find_domain(*domain);
   return  flags;
 }
 
@@ -304,6 +312,7 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
   unsigned int flags = 0;
   unsigned int fwd_flags = 0;
   struct server *start = NULL;
+  struct server_domain *sd = NULL;
   void *hash = hash_questions(header, plen, daemon->namebuff);
 #ifdef HAVE_DNSSEC
   int do_dnssec = 0;
@@ -422,8 +431,10 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
       forward->sentto->failed_queries++;
       if (!option_bool(OPT_ORDER) && old_src)
 	{
+	  sd = forward->sentto->serv_domain;
 	  forward->forwardall = 1;
-	  daemon->last_server = NULL;
+	  if (sd)
+	    sd->last_server = NULL;
 	}
       type = forward->sentto->flags & SERV_TYPE;
 #ifdef HAVE_DNSSEC
@@ -439,8 +450,8 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
       /* new query */
 
       if (gotname)
-	flags = search_servers(now, &addrp, gotname, daemon->namebuff, &type, &domain, &norebind);
-      
+	flags = search_servers(now, &addrp, gotname, daemon->namebuff, &type, &domain, &norebind, &sd);
+
 #ifdef HAVE_DNSSEC
       do_dnssec = type & SERV_DO_DNSSEC;
 #endif
@@ -482,18 +493,18 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
 	     always try all the available servers,
 	     otherwise, use the one last known to work. */
 	  
-	  if (type == 0)
+	  if (sd)
 	    {
 	      if (option_bool(OPT_ORDER))
 		start = daemon->servers;
-	      else if (!(start = daemon->last_server) ||
-		       daemon->forwardcount++ > FORWARD_TEST ||
-		       difftime(now, daemon->forwardtime) > FORWARD_TIME)
+	      else if (!(start = sd->last_server) ||
+		       sd->forwardcount++ > FORWARD_TEST ||
+		       difftime(now, sd->forwardtime) > FORWARD_TIME)
 		{
 		  start = daemon->servers;
 		  forward->forwardall = 1;
-		  daemon->forwardcount = 0;
-		  daemon->forwardtime = now;
+		  sd->forwardcount = 0;
+		  sd->forwardtime = now;
 		}
 	    }
 	  else
@@ -844,6 +855,7 @@ void reply_query(int fd, time_t now)
   size_t nn;
   struct server *server;
   void *hash;
+  struct server_domain *sd;
 
   /* packet buffer overwritten */
   daemon->srv_save = NULL;
@@ -968,7 +980,8 @@ void reply_query(int fd, time_t now)
     }   
    
   server = forward->sentto;
-  if ((forward->sentto->flags & SERV_TYPE) == 0)
+  sd = server->serv_domain;
+  if (sd)
     {
       if (RCODE(header) == REFUSED)
 	server = NULL;
@@ -986,7 +999,7 @@ void reply_query(int fd, time_t now)
 	      }
 	} 
       if (!option_bool(OPT_ALL_SERVERS))
-	daemon->last_server = server;
+	sd->last_server = server;
     }
  
   /* We tried resending to this server with a smaller maximum size and got an answer.
@@ -1093,7 +1106,7 @@ void reply_query(int fd, time_t now)
 		      /* Find server to forward to. This will normally be the 
 			 same as for the original query, but may be another if
 			 servers for domains are involved. */		      
-		      if (search_servers(now, NULL, F_DNSSECOK, daemon->keyname, &type, &domain, NULL) == 0)
+		      if (search_servers(now, NULL, F_DNSSECOK, daemon->keyname, &type, &domain, NULL, &sd) == 0)
 			{
 			  struct server *start, *new_server = NULL;
 			  start = server = forward->sentto;
@@ -1664,7 +1677,7 @@ static int tcp_key_recurse(time_t now, int status, struct dns_header *header, si
       /* Find server to forward to. This will normally be the 
 	 same as for the original query, but may be another if
 	 servers for domains are involved. */		      
-      if (search_servers(now, NULL, F_DNSSECOK, keyname, &type, &domain, NULL) != 0)
+      if (search_servers(now, NULL, F_DNSSECOK, keyname, &type, &domain, NULL, NULL) != 0)
 	{
 	  new_status = STAT_ABANDONED;
 	  break;
@@ -1944,12 +1957,13 @@ unsigned char *tcp_request(int confd, time_t now,
 	      union all_addr *addrp = NULL;
 	      int type = SERV_DO_DNSSEC;
 	      char *domain = NULL;
+	      struct server_domain *sd = NULL;
 	      unsigned char *oph = find_pseudoheader(header, size, NULL, NULL, NULL, NULL);
 
 	      size = add_edns0_config(header, size, ((unsigned char *) header) + 65536, &peer_addr, now, &check_subnet, &cacheable);
 
 	      if (gotname)
-		flags = search_servers(now, &addrp, gotname, daemon->namebuff, &type, &domain, &norebind);
+		flags = search_servers(now, &addrp, gotname, daemon->namebuff, &type, &domain, &norebind, &sd);
 
 #ifdef HAVE_DNSSEC
 	      if (option_bool(OPT_DNSSEC_VALID) && (type & SERV_DO_DNSSEC))
@@ -1970,10 +1984,10 @@ unsigned char *tcp_request(int confd, time_t now,
 
 	      type &= ~SERV_DO_DNSSEC;
 	      
-	      if (type != 0  || option_bool(OPT_ORDER) || !daemon->last_server)
+	      if (!sd  || option_bool(OPT_ORDER) || !sd->last_server)
 		last_server = daemon->servers;
 	      else
-		last_server = daemon->last_server;
+		last_server = sd->last_server;
 	      
 	      if (!flags && last_server)
 		{
@@ -2567,9 +2581,7 @@ void server_gone(struct server *server)
     if (daemon->randomsocks[i].refcount != 0 && daemon->randomsocks[i].serv == server)
       daemon->randomsocks[i].serv = NULL;
   
-  if (daemon->last_server == server)
-    daemon->last_server = NULL;
-  
+  /* last_server cleared by server_domains_cleanup */
   if (daemon->srv_save == server)
     daemon->srv_save = NULL;
 }
diff --git a/src/network.c b/src/network.c
index 3600250..1fa81ff 100644
--- a/src/network.c
+++ b/src/network.c
@@ -1537,6 +1537,29 @@ void cleanup_servers(void)
 #endif
 }
 
+static void server_domains_cleanup(void)
+{
+  struct server_domain *sd, *tmp, **up;
+
+  /* unlink and free anything still marked. */
+  for (up = &daemon->server_domains, sd=*up; sd; sd = tmp)
+    {
+      tmp = sd->next;
+      if (sd->flags & SERV_MARK)
+       {
+         *up = sd->next;
+         if (sd->domain)
+	   free(sd->domain);
+	 free(sd);
+       }
+      else {
+        up = &sd->next;
+        if (sd->last_server && (sd->last_server->flags & SERV_MARK))
+	  sd->last_server = NULL;
+      }
+    }
+}
+
 void add_update_server(int flags,
 		       union mysockaddr *addr,
 		       union mysockaddr *source_addr,
@@ -1616,10 +1639,72 @@ void add_update_server(int flags,
     }
 }
 
+static const char *server_get_domain(const struct server *serv)
+{
+  const char *domain = serv->domain;
+
+  if (serv->flags & SERV_HAS_DOMAIN)
+		  /* .example.com is valid */
+    while (*domain == '.')
+      domain++;
+
+  return domain;
+}
+
+struct server_domain *server_domain_find_domain(const char *domain)
+{
+  struct server_domain *sd;
+  for (sd = daemon->server_domains; sd; sd = sd->next)
+    if ((!domain && sd->domain == domain) || (domain && sd->domain && hostname_isequal(domain, sd->domain)))
+      return sd;
+  return NULL;
+}
+
+/**< Test structure has already set domain pointer.
+ *
+ * If not, create a new record. */
+struct server_domain *server_domain_new(struct server *serv)
+{
+  struct server_domain *sd;
+
+  if ((sd = whine_malloc(sizeof(struct server_domain))))
+    {
+      const char *domain = server_get_domain(serv);
+
+      /* Ensure all serv->domain values have own record in server_domain.
+       * Add a new record. */
+      if (domain)
+	{
+	  size_t len = strlen(domain)+1;
+	  sd->domain = whine_malloc(len);
+	  if (sd->domain)
+	    memcpy(sd->domain, domain, len);
+	}
+      sd->next = daemon->server_domains;
+      serv->serv_domain = sd;
+      daemon->server_domains = sd;
+    }
+  return sd;
+}
+
+/**< Test structure has already set domain pointer.
+ *
+ * If not, create a new record. */
+static void server_domain_check(struct server *serv)
+{
+  struct server_domain *sd = serv->serv_domain;
+
+  if (sd)
+    sd->flags &= (~SERV_MARK); /* found domain, mark active */
+  else
+    server_domain_new(serv);
+}
+
 void check_servers(void)
 {
   struct irec *iface;
   struct server *serv;
+  struct server_domain *sd;
   struct serverfd *sfd, *tmp, **up;
   int port = 0, count;
   int locals = 0;
@@ -1632,10 +1717,14 @@ void check_servers(void)
   for (sfd = daemon->sfds; sfd; sfd = sfd->next)
     sfd->used = sfd->preallocated;
 
+  for (sd = daemon->server_domains; sd; sd = sd->next)
+    sd->flags |= SERV_MARK;
+
   for (count = 0, serv = daemon->servers; serv; serv = serv->next)
     {
       if (!(serv->flags & (SERV_LITERAL_ADDRESS | SERV_NO_ADDR | SERV_USE_RESOLV | SERV_NO_REBIND)))
 	{
+
 	  /* Init edns_pktsz for newly created server records. */
 	  if (serv->edns_pktsz == 0)
 	    serv->edns_pktsz = daemon->edns_pktsz;
@@ -1651,12 +1740,8 @@ void check_servers(void)
 	      if (serv->flags & SERV_HAS_DOMAIN)
 		{
 		  struct ds_config *ds;
-		  char *domain = serv->domain;
-		  
-		  /* .example.com is valid */
-		  while (*domain == '.')
-		    domain++;
-		  
+		  const char *domain = server_get_domain(serv);
+
 		  for (ds = daemon->ds; ds; ds = ds->next)
 		    if (ds->name[0] != 0 && hostname_isequal(domain, ds->name))
 		      break;
@@ -1666,7 +1751,6 @@ void check_servers(void)
 		}
 	    }
 #endif
-
 	  port = prettyprint_addr(&serv->addr, daemon->namebuff);
 	  
 	  /* 0.0.0.0 is nothing, the stack treats it like 127.0.0.1 */
@@ -1701,6 +1785,8 @@ void check_servers(void)
 	  
 	  if (serv->sfd)
 	    serv->sfd->used = 1;
+
+	  server_domain_check(serv);
 	}
       
       if (!(serv->flags & SERV_NO_REBIND) && !(serv->flags & SERV_LITERAL_ADDRESS))
@@ -1763,6 +1849,7 @@ void check_servers(void)
 	up = &sfd->next;
     }
   
+  server_domains_cleanup();
   cleanup_servers();
 }
 
diff --git a/src/option.c b/src/option.c
index 6de5914..e4e3182 100644
--- a/src/option.c
+++ b/src/option.c
@@ -928,6 +928,7 @@ static struct server *add_rev4(struct in_addr addr, int msize)
   p += sprintf(p, "in-addr.arpa");
   
   serv->flags = SERV_HAS_DOMAIN;
+  server_domain_new(serv);
   serv->next = daemon->servers;
   daemon->servers = serv;
 
@@ -952,6 +953,7 @@ static struct server *add_rev6(struct in6_addr *addr, int msize)
   p += sprintf(p, "ip6.arpa");
   
   serv->flags = SERV_HAS_DOMAIN;
+  server_domain_new(serv);
   serv->next = daemon->servers;
   daemon->servers = serv;
   
@@ -2292,6 +2294,7 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 				  memset(serv, 0, sizeof(struct server));
 				  serv->domain = d;
 				  serv->flags = SERV_HAS_DOMAIN | SERV_NO_ADDR;
+				  server_domain_new(serv);
 				  serv->next = daemon->servers;
 				  daemon->servers = serv;
 				}
@@ -2335,6 +2338,7 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 				  memset(serv, 0, sizeof(struct server));
 				  serv->domain = d;
 				  serv->flags = SERV_HAS_DOMAIN | SERV_NO_ADDR;
+				  server_domain_new(serv);
 				  serv->next = daemon->servers;
 				  daemon->servers = serv;
 				}
@@ -2587,6 +2591,7 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 		newlist = serv;
 		serv->domain = domain;
 		serv->flags = domain ? SERV_HAS_DOMAIN : SERV_FOR_NODOTS;
+		server_domain_new(serv);
 		arg = end;
 		if (rebind)
 		  break;
-- 
2.34.1