Fix resolver_getaddrinfo(): use NULL strings in underlying messages

where appropriate and add missing check before freeaddrinfo().
This code path is currently unused.

diff --git a/usr.sbin/smtpd/resolver.c b/usr.sbin/smtpd/resolver.c
index c906cea..2201152 100644 (file)
--- a/usr.sbin/smtpd/resolver.c
+++ b/usr.sbin/smtpd/resolver.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: resolver.c,v 1.2 2018/08/29 17:56:17 eric Exp $       */
+/*     $OpenBSD: resolver.c,v 1.3 2018/11/11 14:56:05 eric Exp $       */
 
 /*
  * Copyright (c) 2017-2018 Eric Faurot <eric@openbsd.org>
@@ -93,7 +93,7 @@ resolver_getaddrinfo(const char *hostname, const char *servname,
        m_add_int(p_resolver, hints ? hints->ai_socktype : 0);
        m_add_int(p_resolver, hints ? hints->ai_protocol : 0);
        m_add_string(p_resolver, hostname);
-       m_add_string(p_resolver, servname ? servname : "");
+       m_add_string(p_resolver, servname);
        m_close(p_resolver);
 }
 
@@ -150,8 +150,7 @@ resolver_dispatch_request(struct mproc *proc, struct imsg *imsg)
                m_get_int(&m, &hints.ai_socktype);
                m_get_int(&m, &hints.ai_protocol);
                m_get_string(&m, &hostname);
-               if (!m_is_eom(&m))
-                       m_get_string(&m, &servname);
+               m_get_string(&m, &servname);
                m_end(&m);
 
                s = NULL;
@@ -257,7 +256,7 @@ resolver_dispatch_result(struct mproc *proc, struct imsg *imsg)
 
                memmove(ai->ai_addr, &ss, ss.ss_len);
 
-               if (cname[0]) {
+               if (cname) {
                        ai->ai_canonname = strdup(cname);
                        if (ai->ai_canonname == NULL) {
                                log_warn("%s: strdup", __func__);
@@ -322,8 +321,7 @@ resolver_getaddrinfo_cb(struct asr_result *ar, void *arg)
                m_add_int(s->proc, ai->ai_socktype);
                m_add_int(s->proc, ai->ai_protocol);
                m_add_sockaddr(s->proc, ai->ai_addr);
-               m_add_string(s->proc, ai->ai_canonname ?
-                   ai->ai_canonname : "");
+               m_add_string(s->proc, ai->ai_canonname);
                m_close(s->proc);
        }
 
@@ -332,7 +330,8 @@ resolver_getaddrinfo_cb(struct asr_result *ar, void *arg)
        m_add_int(s->proc, ar->ar_errno);
        m_close(s->proc);
 
-       freeaddrinfo(ar->ar_addrinfo);
+       if (ar->ar_addrinfo)
+               freeaddrinfo(ar->ar_addrinfo);
        free(s);
 }