Use gethostbyname2 instead of getaddrinfo

In newer glibc, getaddrinfo issues an extra system call to kernel,
which slows down ipset. Replace getaddrinfo with gethostbyname2,
where possible.

diff --git a/configure.ac b/configure.ac
index d9bc2fb2b83e1d893544f8e4d012f21e178df2f6..7b3e70bcc32e6e62b781e9306d31de66f205d4d4 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -162,6 +162,9 @@ AC_CHECK_TYPES([union nf_inet_addr],,,[#include <linux/types.h>
 #include <netinet/in.h>
 #include <linux/netfilter.h>])
 
+dnl Checks for functions
+AC_CHECK_FUNCS(gethostbyname2)
+
 dnl Checks for  compiler characteristics.
 dnl Check extra warning flags except
 dnl    -Wconversion            -> we need it

diff --git a/lib/parse.c b/lib/parse.c
index af2168eb365735d57710c27a9cbb00cd5c38c50a..550048c05914e7797dd98b49866d093c66949b29 100644 (file)
--- a/lib/parse.c
+++ b/lib/parse.c
@@ -24,6 +24,7 @@
 #include <libipset/types.h>                    /* ipset_type_get */
 #include <libipset/utils.h>                    /* string utilities */
 #include <libipset/parse.h>                    /* prototypes */
+#include "../config.h"
 
 #ifndef ULLONG_MAX
 #define ULLONG_MAX     18446744073709551615ULL
@@ -679,6 +680,103 @@ ipset_parse_family(struct ipset_session *session,
  * We resolve hostnames but just the first IP address is used.
  */
 
+static void
+print_warn(struct ipset_session *session)
+{
+       if (!ipset_envopt_test(session, IPSET_ENV_QUIET))
+               fprintf(stderr, "Warning: %s",
+                       ipset_session_warning(session));
+       ipset_session_report_reset(session);
+}
+
+#ifdef HAVE_GETHOSTBYNAME2
+static int
+get_hostbyname2(struct ipset_session *session,
+               enum ipset_opt opt,
+               const char *str,
+               int af)
+{
+       struct hostent *h = gethostbyname2(str, af);
+
+       if (h == NULL) {
+               syntax_err("cannot parse %s: resolving to %s address failed",
+                          str, af == AF_INET ? "IPv4" : "IPv6");
+               return -1;
+       }
+       if (h->h_addr_list[1] != NULL) {
+               ipset_warn(session,
+                          "%s resolves to multiple addresses: "
+                          "using only the first one returned "
+                          "by the resolver.",
+                          str);
+               print_warn(session);
+       }
+
+       return ipset_session_data_set(session, opt, h->h_addr_list[0]);
+}
+
+static int
+parse_ipaddr(struct ipset_session *session,
+            enum ipset_opt opt, const char *str,
+            uint8_t family)
+{
+       uint8_t m = family == NFPROTO_IPV4 ? 32 : 128;
+       int af = family == NFPROTO_IPV4 ? AF_INET : AF_INET6;
+       int err = 0, range = 0;
+       char *saved = ipset_strdup(session, str);
+       char *a, *tmp = saved;
+       enum ipset_opt copt, opt2;
+
+       if (opt == IPSET_OPT_IP) {
+               copt = IPSET_OPT_CIDR;
+               opt2 = IPSET_OPT_IP_TO;
+       } else {
+               copt = IPSET_OPT_CIDR2;
+               opt2 = IPSET_OPT_IP2_TO;
+       }
+
+       if (tmp == NULL)
+               return -1;
+       if ((a = cidr_separator(tmp)) != NULL) {
+               /* IP/mask */
+               *a++ = '\0';
+
+               if ((err = string_to_cidr(session, a, 0, m, &m)) != 0 ||
+                   (err = ipset_session_data_set(session, copt, &m)) != 0)
+                       goto out;
+       } else {
+               a = find_range_separator(session, tmp);
+               if (a == tmp) {
+                       err = -1;
+                       goto out;
+               }
+               if (a != NULL) {
+                       /* IP-IP */
+                       *a++ = '\0';
+                       D("range %s", a);
+                       range++;
+               }
+       }
+       tmp = strip_escape(session, tmp);
+       if (tmp == NULL) {
+               err = -1;
+               goto out;
+       }
+       if ((err = get_hostbyname2(session, opt, tmp, af)) != 0 ||
+           !range)
+               goto out;
+       a = strip_escape(session, a);
+       if (a == NULL) {
+               err = -1;
+               goto out;
+       }
+       err = get_hostbyname2(session, opt2, a, af);
+
+out:
+       free(saved);
+       return err;
+}
+#else
 static struct addrinfo *
 call_getaddrinfo(struct ipset_session *session, const char *str,
                 uint8_t family)
@@ -746,8 +844,9 @@ get_addrinfo(struct ipset_session *session,
                        ipset_warn(session,
                                   "%s resolves to multiple addresses: "
                                   "using only the first one returned "
-                                  "by the resolver",
+                                  "by the resolver.",
                                   str);
+                       print_warn(session);
                }
                found++;
        }
@@ -826,6 +925,7 @@ out:
        free(saved);
        return err;
 }
+#endif
 
 enum ipaddr_type {
        IPADDR_ANY,