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