From 990309a6c118120fd3f5308292d7b41a6dc910d3 Mon Sep 17 00:00:00 2001
From: Tomas Korbar
Date: Thu, 4 May 2023 13:21:26 +0200
Subject: [PATCH] Backport dns SRV record resolution feature (RFC6186)
Resolves: rhbz#2134789
Fix building in ZUUL CI
Resolves: rhbz#2193363
---
postfix-3.5.9-SRV-resolve.patch | 1581 +++++++++++++++++++++++++++++++
postfix-3.5.9-makedefs.patch | 32 +
postfix.spec | 14 +-
3 files changed, 1626 insertions(+), 1 deletion(-)
create mode 100644 postfix-3.5.9-SRV-resolve.patch
create mode 100644 postfix-3.5.9-makedefs.patch
diff --git a/postfix-3.5.9-SRV-resolve.patch b/postfix-3.5.9-SRV-resolve.patch
new file mode 100644
index 0000000..33e2c68
--- /dev/null
+++ b/postfix-3.5.9-SRV-resolve.patch
@@ -0,0 +1,1581 @@
+commit 15dc275ce64c7c715094347456ac62a001f65b08
+Author: Tomas Korbar
+Date: Thu Apr 27 10:45:22 2023 +0200
+
+ Backport SRV record resolution feature
+
+diff --git a/mantools/postlink b/mantools/postlink
+index 490d028..a093c0a 100755
+--- a/mantools/postlink
++++ b/mantools/postlink
+@@ -1129,6 +1129,10 @@ while (<>) {
+ s;\bpostlog_service_name\b;$&;g;
+ s;\bpostlogd_watchdog_timeout\b;$&;g;
+
++ s;\buse_srv_lookup\b;$&;g;
++ s;\ballow_srv_lookup_fallback\b;$&;g;
++ s;\bignore_srv_lookup_error\b;$&;g;
++
+ # Service-defined parameters...
+
+ s;\bpolicy_time_limit\b;$&;g;
+diff --git a/proto/postconf.proto b/proto/postconf.proto
+index 89f9e9b..ca8899f 100644
+--- a/proto/postconf.proto
++++ b/proto/postconf.proto
+@@ -17760,3 +17760,111 @@ value to disable the feature.
+
+ This feature was backported from Postfix 3.6 to Postfix versions
+ 3.5.9, 3.4.19, 3.3.16. 3.2.21.
++
++%PARAM use_srv_lookup
++
++ Enables discovery for the specified service(s) using DNS SRV
++records. For example, with "use_srv_lookup = submission" and
++"relayhost = example.com:submission", the Postfix SMTP client will
++look up DNS SRV records for _submission._tcp.example.com, and will
++relay email through the hosts and ports that are specified with
++those records. See RFC 2782 for details of the host selection
++process.
++
++ Specify zero or more service names separated by comma and/or
++whitespace. Any name in the services(5) database may be specified,
++though in practice only submission, submissions, and smtp make
++sense.
++
++ When SRV record lookup is enabled with use_srv_lookup, you can
++enclose a domain name in "[]" to force IP address lookup instead
++of SRV record lookup.
++
++ Example 1: MUA-to-MTA submission using SRV record lookup for
++the "submission" service for domain "example.com". This uses the
++default SMTP delivery agent with STARTTLS, and looks up SRV records
++for "_submission._tcp.example.com".
++
++
++/etc/postfix/main.cf:
++ use_srv_lookup = submission
++ relayhost = example.com:submission
++ smtp_tls_security_level = may
++ ...see SASL_README for sasl configuration...
++
++
++ Example 2: MUA-to-MTA submission using SRV record lookup for
++the "submissions" service for domain "example.org". This uses a
++dedicated SMTP delivery agent (smtp-wraptls) with tls_wrappermode
++turned on, and looks up SRV records for "_submissions._tcp.example.org".
++
++
++ Note: specify the older name "smtps" instead of "submissions"
++when a provider has DNS SRV records like "_smtps._tcp.example.org"
++instead of "_submissions._tcp.example.org".
++
++
++/etc/postfix/main.cf:
++ use_srv_lookup = submissions
++ default_transport = smtp-wraptls:example.org:submissions
++ ...see SASL_README for sasl configuration...
++
++
++
++/etc/postfix/master.cf:
++ smtp-wraptls unix ... ... ... ... ... smtp
++ -o { smtp_tls_wrappermode = yes }
++ -o { smtp_tls_security_level = encrypt }
++
++
++ Example 3: Sender-dependent selection for a combination of
++MUA-to-MTA submission services. This combines examples 1 and 2 with
++examples of how to disable SRV and look up IP address records for
++"smtp-relay.example.net" and "smtp-relay.other.example". Again,
++specify the older name "smtps" instead of "submissions" when a
++provider has DNS SRV records like "_smtps._tcp.example.org" instead
++of "_submissions._tcp.example.org".
++
++
++/etc/postfix/main.cf:
++ use_srv_lookup = submission, submissions
++ sender_dependent_default_transport_maps = inline:{
++ # Destinations that support SRV record lookup.
++ { user1@example.com = smtp:example.com:submission }
++ { user2@example.org = smtp-wraptls:example.org:submissions }
++ # Use [destination] to force IP address lookups.
++ { user3@example.net = smtp:[smtp-relay.example.net]:submission }
++ { user4@other.example =
++ smtp-wraptls:[smtp-relay.other.example]:submissions } }
++ ...see SASL_README for sasl configuration...
++
++
++ Example 4: MTA-to-MTA traffic, using SRV record lookup for the
++SMTP service. This is useful for Postfix tests, and may be useful
++in environments where ports are dynamically assigned to servers.
++
++
++
++/etc/postfix/main.cf:
++ use_srv_lookup = smtp
++ # Fall back to MX record lookup when SRV records are unavailable.
++ #allow_srv_lookup_fallback = yes
++ #ignore_srv_lookup_error = yes
++
++
++ This feature was backported from Postfix 3.8.
++
++%PARAM ignore_srv_lookup_error no
++
++ When SRV record lookup fails, fall back to MX or IP address
++lookup as if SRV record lookup was not enabled.
++
++ This feature was backported from Postfix 3.8.
++
++%PARAM allow_srv_lookup_fallback no
++
++ When SRV record lookup fails or no SRV record exists, fall back
++to MX or IP address lookup as if SRV record lookup was not enabled.
++
++
This feature was backported from Postfix 3.8.
++
+diff --git a/src/dns/dns.h b/src/dns/dns.h
+index 3631d23..2af1ee2 100644
+--- a/src/dns/dns.h
++++ b/src/dns/dns.h
+@@ -147,10 +147,12 @@ typedef struct DNS_RR {
+ unsigned short class; /* C_IN, etc. */
+ unsigned int ttl; /* always */
+ unsigned int dnssec_valid; /* DNSSEC validated */
+- unsigned short pref; /* T_MX only */
++ unsigned short pref; /* T_MX and T_SRV record related */
++ unsigned short weight; /* T_SRV related, defined in rfc2782 */
++ unsigned short port; /* T_SRV related, defined in rfc2782 */
+ struct DNS_RR *next; /* linkage */
+ size_t data_len; /* actual data size */
+- char data[1]; /* actually a bunch of data */
++ char *data; /* a bunch of data */
+ } DNS_RR;
+
+ /*
+@@ -172,14 +174,29 @@ extern char *dns_strrecord(VSTRING *, DNS_RR *);
+ /*
+ * dns_rr.c
+ */
++#define DNS_RR_NOPREF (0)
++#define DNS_RR_NOWEIGHT (0)
++#define DNS_RR_NOPORT (0)
++
++#define dns_rr_create_noport(qname, rname, type, class, ttl, pref, data, \
++ data_len) \
++ dns_rr_create((qname), (rname), (type), (class), (ttl), \
++ (pref), DNS_RR_NOWEIGHT, DNS_RR_NOPORT, (data), (data_len))
++
++#define dns_rr_create_nopref(qname, rname, type, class, ttl, data, data_len) \
++ dns_rr_create_noport((qname), (rname), (type), (class), (ttl), \
++ DNS_RR_NOPREF, (data), (data_len))
++
+ extern DNS_RR *dns_rr_create(const char *, const char *,
+ ushort, ushort,
+ unsigned, unsigned,
++ unsigned, unsigned,
+ const char *, size_t);
+ extern void dns_rr_free(DNS_RR *);
+ extern DNS_RR *dns_rr_copy(DNS_RR *);
+ extern DNS_RR *dns_rr_append(DNS_RR *, DNS_RR *);
+ extern DNS_RR *dns_rr_sort(DNS_RR *, int (*) (DNS_RR *, DNS_RR *));
++extern DNS_RR *dns_srv_rr_sort(DNS_RR *);
+ extern int dns_rr_compare_pref_ipv6(DNS_RR *, DNS_RR *);
+ extern int dns_rr_compare_pref_ipv4(DNS_RR *, DNS_RR *);
+ extern int dns_rr_compare_pref_any(DNS_RR *, DNS_RR *);
+@@ -283,8 +300,9 @@ extern int dns_lookup_rv(const char *, unsigned, DNS_RR **, VSTRING *,
+ * Below is the precedence order. The order between DNS_RETRY and DNS_NOTFOUND
+ * is arbitrary.
+ */
+-#define DNS_RECURSE (-7) /* internal only: recursion needed */
+-#define DNS_NOTFOUND (-6) /* query ok, data not found */
++#define DNS_RECURSE (-8) /* internal only: recursion needed */
++#define DNS_NOTFOUND (-7) /* query ok, data not found */
++#define DNS_NULLSRV (-6) /* query ok, service unavailable */
+ #define DNS_NULLMX (-5) /* query ok, service unavailable */
+ #define DNS_FAIL (-4) /* query failed, don't retry */
+ #define DNS_INVAL (-3) /* query ok, malformed reply */
+diff --git a/src/dns/dns_lookup.c b/src/dns/dns_lookup.c
+index 4e3e647..93694d9 100644
+--- a/src/dns/dns_lookup.c
++++ b/src/dns/dns_lookup.c
+@@ -691,6 +691,8 @@ static int dns_get_rr(DNS_RR **list, const char *orig_name, DNS_REPLY *reply,
+ int comp_len;
+ ssize_t data_len;
+ unsigned pref = 0;
++ unsigned weight = 0;
++ unsigned port = 0;
+ unsigned char *src;
+ unsigned char *dst;
+ int ch;
+@@ -716,6 +718,18 @@ static int dns_get_rr(DNS_RR **list, const char *orig_name, DNS_REPLY *reply,
+ return (DNS_INVAL);
+ data_len = strlen(temp) + 1;
+ break;
++ case T_SRV:
++ GETSHORT(pref, pos);
++ GETSHORT(weight, pos);
++ GETSHORT(port, pos);
++ if (dn_expand(reply->buf, reply->end, pos, temp, sizeof(temp)) < 0)
++ return (DNS_RETRY);
++ if (*temp == 0)
++ return (DNS_NULLSRV);
++ if (!valid_rr_name(temp, "resource data", fixed->type, reply))
++ return (DNS_INVAL);
++ data_len = strlen(temp) + 1;
++ break;
+ case T_MX:
+ GETSHORT(pref, pos);
+ if (dn_expand(reply->buf, reply->end, pos, temp, sizeof(temp)) < 0)
+@@ -811,7 +825,7 @@ static int dns_get_rr(DNS_RR **list, const char *orig_name, DNS_REPLY *reply,
+ break;
+ }
+ *list = dns_rr_create(orig_name, rr_name, fixed->type, fixed->class,
+- fixed->ttl, pref, tempbuf, data_len);
++ fixed->ttl, pref, weight, port, tempbuf, data_len);
+ return (DNS_OK);
+ }
+
+@@ -911,7 +925,7 @@ static int dns_get_answer(const char *orig_name, DNS_REPLY *reply, int type,
+ resource_found++;
+ rr->dnssec_valid = *maybe_secure ? reply->dnssec_ad : 0;
+ *rrlist = dns_rr_append(*rrlist, rr);
+- } else if (status == DNS_NULLMX) {
++ } else if (status == DNS_NULLMX || status == DNS_NULLSRV) {
+ CORRUPT(status); /* TODO: use better name */
+ } else if (not_found_status != DNS_RETRY)
+ not_found_status = status;
+@@ -1045,6 +1059,12 @@ int dns_lookup_x(const char *name, unsigned type, unsigned flags,
+ name);
+ SET_H_ERRNO(NO_DATA);
+ return (status);
++ case DNS_NULLSRV:
++ if (why)
++ vstring_sprintf(why, "Domain %s does not support SRV requests",
++ name);
++ SET_H_ERRNO(NO_DATA);
++ return (status);
+ case DNS_OK:
+ if (rrlist && dns_rr_filter_maps) {
+ if (dns_rr_filter_execute(rrlist) < 0) {
+diff --git a/src/dns/dns_rr.c b/src/dns/dns_rr.c
+index b550788..15b5dee 100644
+--- a/src/dns/dns_rr.c
++++ b/src/dns/dns_rr.c
+@@ -7,13 +7,15 @@
+ /* #include
+ /*
+ /* DNS_RR *dns_rr_create(qname, rname, type, class, ttl, preference,
+-/* data, data_len)
++/* weight, port, data, data_len)
+ /* const char *qname;
+ /* const char *rname;
+ /* unsigned short type;
+ /* unsigned short class;
+ /* unsigned int ttl;
+ /* unsigned preference;
++/* unsigned weight;
++/* unsigned port;
+ /* const char *data;
+ /* size_t data_len;
+ /*
+@@ -49,6 +51,30 @@
+ /* DNS_RR *dns_rr_remove(list, record)
+ /* DNS_RR *list;
+ /* DNS_RR *record;
++/*
++/* DNS_RR *dns_srv_rr_sort(list)
++/* DNS_RR *list;
++/* AUXILIARY FUNCTIONS
++/* DNS_RR *dns_rr_create_nopref(qname, rname, type, class, ttl,
++/* data, data_len)
++/* const char *qname;
++/* const char *rname;
++/* unsigned short type;
++/* unsigned short class;
++/* unsigned int ttl;
++/* const char *data;
++/* size_t data_len;
++/*
++/* DNS_RR *dns_rr_create_noport(qname, rname, type, class, ttl,
++/* preference, data, data_len)
++/* const char *qname;
++/* const char *rname;
++/* unsigned short type;
++/* unsigned short class;
++/* unsigned int ttl;
++/* unsigned preference;
++/* const char *data;
++/* size_t data_len;
+ /* DESCRIPTION
+ /* The routines in this module maintain memory for DNS resource record
+ /* information, and maintain lists of DNS resource records.
+@@ -56,10 +82,14 @@
+ /* dns_rr_create() creates and initializes one resource record.
+ /* The \fIqname\fR field specifies the query name.
+ /* The \fIrname\fR field specifies the reply name.
+-/* \fIpreference\fR is used for MX records; \fIdata\fR is a null
++/* \fIpreference\fR is used for MX and SRV records; \fIweight\fR
++/* and \fIport\fR are used for SRV records; \fIdata\fR is a null
+ /* pointer or specifies optional resource-specific data;
+ /* \fIdata_len\fR is the amount of resource-specific data.
+ /*
++/* dns_rr_create_nopref() and dns_rr_create_noport() are convenience
++/* wrappers around dns_rr_create() that take fewer arguments.
++/*
+ /* dns_rr_free() releases the resource used by of zero or more
+ /* resource records.
+ /*
+@@ -81,6 +111,9 @@
+ /* dns_rr_remove() removes the specified record from the specified list.
+ /* The updated list is the result value.
+ /* The record MUST be a list member.
++/*
++/* dns_srv_rr_sort() sorts a list of SRV records according to
++/* their priority and weight as described in RFC 2782.
+ /* LICENSE
+ /* .ad
+ /* .fi
+@@ -113,11 +146,15 @@
+ DNS_RR *dns_rr_create(const char *qname, const char *rname,
+ ushort type, ushort class,
+ unsigned int ttl, unsigned pref,
++ unsigned weight, unsigned port,
+ const char *data, size_t data_len)
+ {
+ DNS_RR *rr;
+
+- rr = (DNS_RR *) mymalloc(sizeof(*rr) + data_len - 1);
++ /*
++ * Note: if this function is changed, update dns_rr_copy().
++ */
++ rr = (DNS_RR *) mymalloc(sizeof(*rr));
+ rr->qname = mystrdup(qname);
+ rr->rname = mystrdup(rname);
+ rr->type = type;
+@@ -125,8 +162,14 @@ DNS_RR *dns_rr_create(const char *qname, const char *rname,
+ rr->ttl = ttl;
+ rr->dnssec_valid = 0;
+ rr->pref = pref;
+- if (data && data_len > 0)
++ rr->weight = weight;
++ rr->port = port;
++ if (data_len != 0) {
++ rr->data = mymalloc(data_len);
+ memcpy(rr->data, data, data_len);
++ } else {
++ rr->data = 0;
++ }
+ rr->data_len = data_len;
+ rr->next = 0;
+ return (rr);
+@@ -141,6 +184,8 @@ void dns_rr_free(DNS_RR *rr)
+ dns_rr_free(rr->next);
+ myfree(rr->qname);
+ myfree(rr->rname);
++ if (rr->data)
++ myfree(rr->data);
+ myfree((void *) rr);
+ }
+ }
+@@ -149,16 +194,17 @@ void dns_rr_free(DNS_RR *rr)
+
+ DNS_RR *dns_rr_copy(DNS_RR *src)
+ {
+- ssize_t len = sizeof(*src) + src->data_len - 1;
+ DNS_RR *dst;
+
+ /*
+- * Combine struct assignment and data copy in one block copy operation.
++ * Note: struct copy, because dns_rr_create() would not copy all fields.
+ */
+- dst = (DNS_RR *) mymalloc(len);
+- memcpy((void *) dst, (void *) src, len);
++ dst = (DNS_RR *) mymalloc(sizeof(*dst));
++ *dst = *src;
+ dst->qname = mystrdup(src->qname);
+ dst->rname = mystrdup(src->rname);
++ if (dst->data)
++ dst->data = mymemdup(src->data, src->data_len);
+ dst->next = 0;
+ return (dst);
+ }
+@@ -247,6 +293,12 @@ DNS_RR *dns_rr_sort(DNS_RR *list, int (*compar) (DNS_RR *, DNS_RR *))
+ int len;
+ int i;
+
++ /*
++ * Avoid mymalloc() panic.
++ */
++ if (list == 0)
++ return (list);
++
+ /*
+ * Save state and initialize.
+ */
+@@ -293,6 +345,12 @@ DNS_RR *dns_rr_shuffle(DNS_RR *list)
+ int i;
+ int r;
+
++ /*
++ * Avoid mymalloc() panic.
++ */
++ if (list == 0)
++ return (list);
++
+ /*
+ * Build linear array with pointers to each list element.
+ */
+@@ -345,3 +403,141 @@ DNS_RR *dns_rr_remove(DNS_RR *list, DNS_RR *record)
+ }
+ return (list);
+ }
++
++/* weight_order - sort equal-priority records by weight */
++
++static void weight_order(DNS_RR **array, int count)
++{
++ int unordered_weights;
++ int i;
++
++ /*
++ * Compute the sum of record weights. If weights are not supplied then
++ * this function would be a noop. In fact this would be a noop when all
++ * weights have the same value, whether that weight is zero or not. There
++ * is no need to give special treatment to zero weights.
++ */
++ for (unordered_weights = 0, i = 0; i < count; i++)
++ unordered_weights += array[i]->weight;
++ if (unordered_weights == 0)
++ return;
++
++ /*
++ * The record ordering code below differs from RFC 2782 when the input
++ * contains a mix of zero and non-zero weights: the code below does not
++ * give special treatment to zero weights. Instead, it treats a zero
++ * weight just like any other small weight. Fewer special cases make for
++ * code that is simpler and more robust.
++ */
++ for (i = 0; i < count - 1; i++) {
++ int running_sum;
++ int threshold;
++ int k;
++ DNS_RR *temp;
++
++ /*
++ * Choose a random threshold [0..unordered_weights] inclusive.
++ */
++ threshold = myrand() % (unordered_weights + 1);
++
++ /*
++ * Move the first record with running_sum >= threshold to the ordered
++ * list, and update unordered_weights.
++ */
++ for (running_sum = 0, k = i; k < count; k++) {
++ running_sum += array[k]->weight;
++ if (running_sum >= threshold) {
++ unordered_weights -= array[k]->weight;
++ temp = array[i];
++ array[i] = array[k];
++ array[k] = temp;
++ break;
++ }
++ }
++ }
++}
++
++/* dns_srv_rr_sort - sort resource record list */
++
++DNS_RR *dns_srv_rr_sort(DNS_RR *list)
++{
++ int (*saved_user) (DNS_RR *, DNS_RR *);
++ DNS_RR **rr_array;
++ DNS_RR *rr;
++ int len;
++ int i;
++ int r;
++ int cur_pref;
++ int left_bound; /* inclusive */
++ int right_bound; /* non-inclusive */
++
++ /*
++ * Avoid mymalloc() panic, or rr_array[0] fence-post error.
++ */
++ if (list == 0)
++ return (list);
++
++ /*
++ * Save state and initialize.
++ */
++ saved_user = dns_rr_sort_user;
++ dns_rr_sort_user = dns_rr_compare_pref_any;
++
++ /*
++ * Build linear array with pointers to each list element.
++ */
++ for (len = 0, rr = list; rr != 0; len++, rr = rr->next)
++ /* void */ ;
++ rr_array = (DNS_RR **) mymalloc(len * sizeof(*rr_array));
++ for (len = 0, rr = list; rr != 0; len++, rr = rr->next)
++ rr_array[len] = rr;
++
++ /*
++ * Shuffle resource records. Every element has an equal chance of landing
++ * in slot 0. After that every remaining element has an equal chance of
++ * landing in slot 1, ... This is exactly n! states for n! permutations.
++ */
++ for (i = 0; i < len - 1; i++) {
++ r = i + (myrand() % (len - i)); /* Victor&Son */
++ rr = rr_array[i];
++ rr_array[i] = rr_array[r];
++ rr_array[r] = rr;
++ }
++
++ /* First order the records by preference. */
++ qsort((void *) rr_array, len, sizeof(*rr_array), dns_rr_sort_callback);
++
++ /*
++ * Walk through records and sort the records in every same-preference
++ * partition according to their weight. Note that left_bound is
++ * inclusive, and that right-bound is non-inclusive.
++ */
++ left_bound = 0;
++ cur_pref = rr_array[left_bound]->pref; /* assumes len > 0 */
++
++ for (right_bound = 1; /* see below */ ; right_bound++) {
++ if (right_bound == len || rr_array[right_bound]->pref != cur_pref) {
++ if (right_bound - left_bound > 1)
++ weight_order(rr_array + left_bound, right_bound - left_bound);
++ if (right_bound == len)
++ break;
++ left_bound = right_bound;
++ cur_pref = rr_array[left_bound]->pref;
++ }
++ }
++
++ /*
++ * Fix the links.
++ */
++ for (i = 0; i < len - 1; i++)
++ rr_array[i]->next = rr_array[i + 1];
++ rr_array[i]->next = 0;
++ list = rr_array[0];
++
++ /*
++ * Cleanup.
++ */
++ myfree((void *) rr_array);
++ dns_rr_sort_user = saved_user;
++ return (list);
++}
+diff --git a/src/dns/dns_sa_to_rr.c b/src/dns/dns_sa_to_rr.c
+index 6b9efcc..b5dee20 100644
+--- a/src/dns/dns_sa_to_rr.c
++++ b/src/dns/dns_sa_to_rr.c
+@@ -55,14 +55,14 @@ DNS_RR *dns_sa_to_rr(const char *hostname, unsigned pref, struct sockaddr *sa)
+ #define DUMMY_TTL 0
+
+ if (sa->sa_family == AF_INET) {
+- return (dns_rr_create(hostname, hostname, T_A, C_IN, DUMMY_TTL, pref,
+- (char *) &SOCK_ADDR_IN_ADDR(sa),
+- sizeof(SOCK_ADDR_IN_ADDR(sa))));
++ return (dns_rr_create_noport(hostname, hostname, T_A, C_IN, DUMMY_TTL,
++ pref, (char *) &SOCK_ADDR_IN_ADDR(sa),
++ sizeof(SOCK_ADDR_IN_ADDR(sa))));
+ #ifdef HAS_IPV6
+ } else if (sa->sa_family == AF_INET6) {
+- return (dns_rr_create(hostname, hostname, T_AAAA, C_IN, DUMMY_TTL, pref,
+- (char *) &SOCK_ADDR_IN6_ADDR(sa),
+- sizeof(SOCK_ADDR_IN6_ADDR(sa))));
++ return (dns_rr_create_noport(hostname, hostname, T_AAAA, C_IN, DUMMY_TTL,
++ pref, (char *) &SOCK_ADDR_IN6_ADDR(sa),
++ sizeof(SOCK_ADDR_IN6_ADDR(sa))));
+ #endif
+ } else {
+ errno = EAFNOSUPPORT;
+@@ -121,7 +121,7 @@ int main(int argc, char **argv)
+ resv[len++] = res;
+ qsort((void *) resv, len, sizeof(*resv), compare_family);
+ for (n = 0; n < len; n++) {
+- if ((rr = dns_sa_to_rr(argv[0], 0, resv[n]->ai_addr)) == 0)
++ if ((rr = dns_sa_to_rr(argv[0], DNS_RR_NOPREF, resv[n]->ai_addr)) == 0)
+ msg_fatal("dns_sa_to_rr: %m");
+ if (dns_rr_to_pa(rr, &hostaddr) == 0)
+ msg_fatal("dns_rr_to_pa: %m");
+diff --git a/src/dns/dns_strrecord.c b/src/dns/dns_strrecord.c
+index 6b8e989..1e3b743 100644
+--- a/src/dns/dns_strrecord.c
++++ b/src/dns/dns_strrecord.c
+@@ -80,6 +80,10 @@ char *dns_strrecord(VSTRING *buf, DNS_RR *rr)
+ case T_MX:
+ vstring_sprintf_append(buf, "%u %s.", rr->pref, rr->data);
+ break;
++ case T_SRV:
++ vstring_sprintf_append(buf, "%u %u %u %s.", rr->pref, rr->weight,
++ rr->port, rr->data);
++ break;
+ case T_TLSA:
+ if (rr->data_len >= 3) {
+ uint8_t *ip = (uint8_t *) rr->data;
+diff --git a/src/dns/dns_strtype.c b/src/dns/dns_strtype.c
+index 70e59ac..7eebe3c 100644
+--- a/src/dns/dns_strtype.c
++++ b/src/dns/dns_strtype.c
+@@ -180,6 +180,9 @@ static struct dns_type_map dns_type_map[] = {
+ #ifdef T_ANY
+ T_ANY, "ANY",
+ #endif
++#ifdef T_SRV
++ T_SRV, "SRV",
++#endif
+ };
+
+ /* dns_strtype - translate DNS query type to string */
+diff --git a/src/global/mail_params.h b/src/global/mail_params.h
+index 27b17d5..e8d9c28 100644
+--- a/src/global/mail_params.h
++++ b/src/global/mail_params.h
+@@ -4209,6 +4209,21 @@ extern char *var_info_log_addr_form;
+ #define DEF_DNSSEC_PROBE "ns:."
+ extern char *var_dnssec_probe;
+
++ /*
++ * SRV lookup support.
++ */
++#define VAR_USE_SRV_LOOKUP "use_srv_lookup"
++#define DEF_USE_SRV_LOOKUP ""
++extern char *var_use_srv_lookup;
++
++#define VAR_IGN_SRV_LOOKUP_ERR "ignore_srv_lookup_error"
++#define DEF_IGN_SRV_LOOKUP_ERR 0
++extern bool var_ign_srv_lookup_err;
++
++#define VAR_ALLOW_SRV_FALLBACK "allow_srv_lookup_fallback"
++#define DEF_ALLOW_SRV_FALLBACK 0
++extern bool var_allow_srv_fallback;
++
+ /* LICENSE
+ /* .ad
+ /* .fi
+diff --git a/src/posttls-finger/posttls-finger.c b/src/posttls-finger/posttls-finger.c
+index a3a9946..a56bad1 100644
+--- a/src/posttls-finger/posttls-finger.c
++++ b/src/posttls-finger/posttls-finger.c
+@@ -236,6 +236,8 @@
+ /* is encountered, up to 5 times or as specified with the \fB-m\fR option.
+ /* By default reconnection is disabled, specify a positive delay to
+ /* enable this behavior.
++/* .IP "\fB-R\fR"
++/* Use SRV lookup instead of MX.
+ /* .IP "\fB-s \fIservername\fR"
+ /* The server name to send with the TLS Server Name Indication (SNI)
+ /* extension. When the server has DANE TLSA records, this parameter
+@@ -466,6 +468,7 @@ typedef struct STATE {
+ DNS_RR *mx; /* MX RRset qname, rname, valid */
+ int pass; /* Pass number, 2 for reconnect */
+ int nochat; /* disable chat logging */
++ int dosrv; /* look up SRV records instead of MX */
+ char *helo; /* Server name from EHLO reply */
+ DSN_BUF *why; /* SMTP-style error message */
+ VSTRING *buffer; /* Response buffer */
+@@ -1150,7 +1153,7 @@ static VSTREAM *connect_addr(STATE *state, DNS_RR *addr)
+ /* addr_one - address lookup for one host name */
+
+ static DNS_RR *addr_one(STATE *state, DNS_RR *addr_list, const char *host,
+- int res_opt, unsigned pref)
++ int res_opt, unsigned pref, unsigned port)
+ {
+ static const char *myname = "addr_one";
+ DSN_BUF *why = state->why;
+@@ -1173,6 +1176,8 @@ static DNS_RR *addr_one(STATE *state, DNS_RR *addr_list, const char *host,
+ if ((addr = dns_sa_to_rr(host, pref, res0->ai_addr)) == 0)
+ msg_fatal("host %s: conversion error for address family %d: %m",
+ host, ((struct sockaddr *) (res0->ai_addr))->sa_family);
++ addr->pref = pref;
++ addr->port = port;
+ addr_list = dns_rr_append(addr_list, addr);
+ freeaddrinfo(res0);
+ return (addr_list);
+@@ -1189,8 +1194,10 @@ static DNS_RR *addr_one(STATE *state, DNS_RR *addr_list, const char *host,
+ why->reason, DNS_REQ_FLAG_NONE,
+ proto_info->dns_atype_list)) {
+ case DNS_OK:
+- for (rr = addr; rr; rr = rr->next)
++ for (rr = addr; rr; rr = rr->next) {
+ rr->pref = pref;
++ rr->port = port;
++ }
+ addr_list = dns_rr_append(addr_list, addr);
+ return (addr_list);
+ default:
+@@ -1277,15 +1284,15 @@ static DNS_RR *mx_addr_list(STATE *state, DNS_RR *mx_names)
+ #endif
+
+ for (rr = mx_names; rr; rr = rr->next) {
+- if (rr->type != T_MX)
++ if (rr->type != T_MX && rr->type != T_SRV)
+ msg_panic("%s: bad resource type: %d", myname, rr->type);
+ addr_list = addr_one(state, addr_list, (char *) rr->data, res_opt,
+- rr->pref);
++ rr->pref, rr->port);
+ }
+ return (addr_list);
+ }
+
+-/* smtp_domain_addr - mail exchanger address lookup */
++/* domain_addr - mail exchanger address lookup */
+
+ static DNS_RR *domain_addr(STATE *state, char *domain)
+ {
+@@ -1350,6 +1357,74 @@ static DNS_RR *domain_addr(STATE *state, char *domain)
+ return (addr_list);
+ }
+
++/* service_addr - mail exchanger address lookup */
++
++static DNS_RR *service_addr(STATE *state, const char *domain,
++ const char *service)
++{
++ VSTRING *srv_qname = vstring_alloc(100);
++ char *str_srv_qname;
++ DNS_RR *srv_names;
++ DNS_RR *addr_list = 0;
++ int r = 0; /* Resolver flags */
++ const char *aname;
++
++ dsb_reset(state->why);
++
++#if (RES_USE_DNSSEC != 0) && (RES_USE_EDNS0 != 0)
++ r |= RES_USE_DNSSEC;
++#endif
++
++ vstring_sprintf(srv_qname, "_%s._tcp.%s", service, domain);
++ str_srv_qname = STR(srv_qname);
++
++ /*
++ * IDNA support.
++ */
++#ifndef NO_EAI
++ if (!allascii(str_srv_qname)
++ && (aname = midna_domain_to_ascii(str_srv_qname)) != 0) {
++ msg_info("%s asciified to %s", str_srv_qname, aname);
++ } else
++#endif
++ aname = str_srv_qname;
++
++ switch (dns_lookup(aname, T_SRV, r, &srv_names, (VSTRING *) 0,
++ state->why->reason)) {
++ default:
++ dsb_status(state->why, "4.4.3");
++ break;
++ case DNS_INVAL:
++ dsb_status(state->why, "5.4.4");
++ break;
++ case DNS_NULLMX:
++ dsb_status(state->why, "5.1.0");
++ break;
++ case DNS_FAIL:
++ dsb_status(state->why, "5.4.3");
++ break;
++ case DNS_OK:
++ /* Shuffle then sort the SRV rr records by priority and weight. */
++ srv_names = dns_srv_rr_sort(srv_names);
++ addr_list = mx_addr_list(state, srv_names);
++ state->mx = dns_rr_copy(srv_names);
++ dns_rr_free(srv_names);
++ if (addr_list == 0) {
++ msg_warn("no SRV host for %s has a valid address record",
++ str_srv_qname);
++ break;
++ }
++ /* TODO: sort by priority, weight, and address family preference. */
++ break;
++ case DNS_NOTFOUND:
++ dsb_status(state->why, "5.4.4");
++ break;
++ }
++
++ vstring_free(srv_qname);
++ return (addr_list);
++}
++
+ /* host_addr - direct host lookup */
+
+ static DNS_RR *host_addr(STATE *state, const char *host)
+@@ -1376,7 +1451,8 @@ static DNS_RR *host_addr(STATE *state, const char *host)
+ ahost = host;
+
+ #define PREF0 0
+- addr_list = addr_one(state, (DNS_RR *) 0, ahost, res_opt, PREF0);
++#define NOPORT 0
++ addr_list = addr_one(state, (DNS_RR *) 0, ahost, res_opt, PREF0, NOPORT);
+ if (addr_list && addr_list->next) {
+ addr_list = dns_rr_shuffle(addr_list);
+ if (inet_proto_info()->ai_family_list[1] != 0)
+@@ -1465,7 +1541,8 @@ static int dane_host_level(STATE *state, DNS_RR *addr)
+ /* parse_destination - parse host/port destination */
+
+ static char *parse_destination(char *destination, char *def_service,
+- char **hostp, unsigned *portp)
++ char **hostp, char **servicep,
++ unsigned *portp)
+ {
+ char *buf = mystrdup(destination);
+ char *service;
+@@ -1481,12 +1558,13 @@ static char *parse_destination(char *destination, char *def_service,
+ * Parse the host/port information. We're working with a copy of the
+ * destination argument so the parsing can be destructive.
+ */
+- if ((err = host_port(buf, hostp, (char *) 0, &service, def_service)) != 0)
++ if ((err = host_port(buf, hostp, (char *) 0, servicep, def_service)) != 0)
+ msg_fatal("%s in server description: %s", err, destination);
+
+ /*
+ * Convert service to port number, network byte order.
+ */
++ service = *servicep;
+ if (alldig(service)) {
+ if ((port = atoi(service)) >= 65536 || port == 0)
+ msg_fatal("bad network port in destination: %s", destination);
+@@ -1509,15 +1587,18 @@ static void connect_remote(STATE *state, char *dest)
+ DNS_RR *addr;
+ char *buf;
+ char *domain;
++ char *service;
+
+ /* When reconnecting use IP address of previous session */
+ if (state->addr == 0) {
+ buf = parse_destination(dest, state->smtp ? "smtp" : "24",
+- &domain, &state->port);
++ &domain, service, &state->port);
+ if (!state->nexthop)
+ state->nexthop = mystrdup(domain);
+ if (state->smtp == 0 || *dest == '[')
+ state->addr = host_addr(state, domain);
++ else if (state->dosrv)
++ state->addr = service_addr(state, domain, service);
+ else
+ state->addr = domain_addr(state, domain);
+ myfree(buf);
+@@ -1531,10 +1612,14 @@ static void connect_remote(STATE *state, char *dest)
+ for (addr = state->addr; addr; addr = addr->next) {
+ int level = dane_host_level(state, addr);
+
++ if (addr->port) /* SRV port override */
++ state->port = htons(addr->port);
++
+ if (level == TLS_LEV_INVALID
+ || (state->stream = connect_addr(state, addr)) == 0) {
+- msg_info("Failed to establish session to %s via %s: %s",
+- dest, HNAME(addr), vstring_str(state->why->reason));
++ msg_info("Failed to establish session to %s:%s via %s:%u: %s",
++ dest, service, HNAME(addr), addr->port,
++ vstring_str(state->why->reason));
+ continue;
+ }
+ /* We have a connection */
+@@ -1819,6 +1904,7 @@ static void parse_options(STATE *state, int argc, char *argv[])
+
+ state->smtp = 1;
+ state->pass = 1;
++ state->dosrv = 0;
+ state->reconnect = -1;
+ state->max_reconnect = 5;
+ state->wrapper_mode = 0;
+@@ -1829,7 +1915,7 @@ static void parse_options(STATE *state, int argc, char *argv[])
+ memset((void *) &state->options, 0, sizeof(state->options));
+ state->options.host_lookup = mystrdup("dns");
+
+-#define OPTS "a:ch:o:St:T:v"
++#define OPTS "a:ch:o:RSt:T:v"
+ #ifdef USE_TLS
+ #define TLSOPTS "A:Cd:fF:g:H:k:K:l:L:m:M:p:P:r:s:wX"
+
+@@ -1868,6 +1954,9 @@ static void parse_options(STATE *state, int argc, char *argv[])
+ case 'o':
+ override(optarg);
+ break;
++ case 'R':
++ state->dosrv = 1;
++ break;
+ case 'S':
+ state->smtp = 0;
+ break;
+diff --git a/src/smtp/lmtp_params.c b/src/smtp/lmtp_params.c
+index 973cb5d..ff074cd 100644
+--- a/src/smtp/lmtp_params.c
++++ b/src/smtp/lmtp_params.c
+@@ -64,6 +64,7 @@
+ VAR_LMTP_DSN_FILTER, DEF_LMTP_DSN_FILTER, &var_smtp_dsn_filter, 0, 0,
+ VAR_LMTP_DNS_RE_FILTER, DEF_LMTP_DNS_RE_FILTER, &var_smtp_dns_re_filter, 0, 0,
+ VAR_TLSPROXY_SERVICE, DEF_TLSPROXY_SERVICE, &var_tlsproxy_service, 1, 0,
++ VAR_USE_SRV_LOOKUP, DEF_USE_SRV_LOOKUP, &var_use_srv_lookup, 0, 0,
+ 0,
+ };
+ static const CONFIG_TIME_TABLE lmtp_time_table[] = {
+@@ -126,5 +127,7 @@
+ VAR_LMTP_REC_DEADLINE, DEF_LMTP_REC_DEADLINE, &var_smtp_rec_deadline,
+ VAR_LMTP_DUMMY_MAIL_AUTH, DEF_LMTP_DUMMY_MAIL_AUTH, &var_smtp_dummy_mail_auth,
+ VAR_LMTP_BALANCE_INET_PROTO, DEF_LMTP_BALANCE_INET_PROTO, &var_smtp_balance_inet_proto,
++ VAR_IGN_SRV_LOOKUP_ERR, DEF_IGN_SRV_LOOKUP_ERR, &var_ign_srv_lookup_err,
++ VAR_ALLOW_SRV_FALLBACK, DEF_ALLOW_SRV_FALLBACK, &var_allow_srv_fallback,
+ 0,
+ };
+diff --git a/src/smtp/smtp.c b/src/smtp/smtp.c
+index e46ebd6..2cc9e2f 100644
+--- a/src/smtp/smtp.c
++++ b/src/smtp/smtp.c
+@@ -146,6 +146,7 @@
+ /* RFC 2046 (MIME: Media Types)
+ /* RFC 2554 (AUTH command)
+ /* RFC 2821 (SMTP protocol)
++/* RFC 2782 (SRV resource records)
+ /* RFC 2920 (SMTP Pipelining)
+ /* RFC 3207 (STARTTLS command)
+ /* RFC 3461 (SMTP DSN Extension)
+@@ -336,6 +337,17 @@
+ /* The DNS query type (default: "ns") and DNS query name (default:
+ /* ".") that Postfix may use to determine whether DNSSEC validation
+ /* is available.
++/* .PP
++/* Backported from Postfix version 3.8:
++/* .IP "\fBuse_srv_lookup (empty)\fR"
++/* Enables discovery for the specified service(s) using DNS SRV
++/* records.
++/* .IP "\fBignore_srv_lookup_error (no)\fR"
++/* When SRV record lookup fails, fall back to MX or IP address
++/* lookup as if SRV record lookup was not enabled.
++/* .IP "\fBallow_srv_lookup_fallback (no)\fR"
++/* When SRV record lookup fails or no SRV record exists, fall back
++/* to MX or IP address lookup as if SRV record lookup was not enabled.
+ /* MIME PROCESSING CONTROLS
+ /* .ad
+ /* .fi
+@@ -1052,6 +1064,9 @@ bool var_smtp_dummy_mail_auth;
+ char *var_smtp_dsn_filter;
+ char *var_smtp_dns_re_filter;
+ bool var_smtp_balance_inet_proto;
++char *var_use_srv_lookup;
++bool var_ign_srv_lookup_err;
++bool var_allow_srv_fallback;
+
+ /* Special handling of 535 AUTH errors. */
+ char *var_smtp_sasl_auth_cache_name;
+@@ -1074,6 +1089,7 @@ MAPS *smtp_pix_bug_maps;
+ HBC_CHECKS *smtp_header_checks; /* limited header checks */
+ HBC_CHECKS *smtp_body_checks; /* limited body checks */
+ SMTP_CLI_ATTR smtp_cli_attr; /* parsed command-line */
++STRING_LIST *smtp_use_srv_lookup;
+
+ #ifdef USE_TLS
+
+@@ -1357,6 +1373,14 @@ static void post_init(char *unused_name, char **argv)
+ * the process lifetime.
+ */
+ get_cli_attr(&smtp_cli_attr, argv);
++
++ /*
++ * Service discovery with SRV record lookup.
++ */
++ if (*var_use_srv_lookup)
++ smtp_use_srv_lookup = string_list_init(VAR_USE_SRV_LOOKUP,
++ MATCH_FLAG_RETURN,
++ var_use_srv_lookup);
+ }
+
+ /* pre_init - pre-jail initialization */
+diff --git a/src/smtp/smtp.h b/src/smtp/smtp.h
+index 281cfe4..3f4c209 100644
+--- a/src/smtp/smtp.h
++++ b/src/smtp/smtp.h
+@@ -84,6 +84,14 @@ typedef struct SMTP_ITERATOR {
+ vstring_strcpy((iter)->dest, STR((iter)->saved_dest)); \
+ } while (0)
+
++#define SMTP_ITER_UPDATE_HOST(iter, _host, _addr, _rr) do { \
++ vstring_strcpy((iter)->host, (_host)); \
++ vstring_strcpy((iter)->addr, (_addr)); \
++ (iter)->rr = (_rr); \
++ if ((_rr)->port) \
++ (iter)->port = htons((_rr)->port); /* SRV port override */ \
++ } while (0)
++
+ /*
+ * TLS Policy support.
+ */
+@@ -261,6 +269,7 @@ typedef struct SMTP_STATE {
+ #define SMTP_MISC_FLAG_COMPLETE_SESSION (1<<7)
+ #define SMTP_MISC_FLAG_PREF_IPV6 (1<<8)
+ #define SMTP_MISC_FLAG_PREF_IPV4 (1<<9)
++#define SMTP_MISC_FLAG_FALLBACK_SRV_TO_MX (1<<10)
+
+ #define SMTP_MISC_FLAG_CONN_CACHE_MASK \
+ (SMTP_MISC_FLAG_CONN_LOAD | SMTP_MISC_FLAG_CONN_STORE)
+@@ -300,6 +309,8 @@ extern MAPS *smtp_generic_maps; /* make internal address valid */
+ extern int smtp_ext_prop_mask; /* address externsion propagation */
+ extern unsigned smtp_dns_res_opt; /* DNS query flags */
+
++extern STRING_LIST *smtp_use_srv_lookup;/* services with SRV record lookup */
++
+ #ifdef USE_TLS
+
+ extern TLS_APPL_STATE *smtp_tls_ctx; /* client-side TLS engine */
+diff --git a/src/smtp/smtp_addr.c b/src/smtp/smtp_addr.c
+index 2210ff7..7f20838 100644
+--- a/src/smtp/smtp_addr.c
++++ b/src/smtp/smtp_addr.c
+@@ -17,6 +17,15 @@
+ /* char *name;
+ /* int misc_flags;
+ /* DSN_BUF *why;
++/*
++/* DNS_RR *smtp_service_addr(name, service, mxrr, misc_flags, why,
++/* found_myself)
++/* const char *name;
++/* const char *service;
++/* DNS_RR **mxrr;
++/* int misc_flags;
++/* DSN_BUF *why;
++/* int *found_myself;
+ /* DESCRIPTION
+ /* This module implements Internet address lookups. By default,
+ /* lookups are done via the Internet domain name service (DNS).
+@@ -33,6 +42,8 @@
+ /* destination. If MX records were found, the rname, qname,
+ /* and dnssec validation status of the MX RRset are returned
+ /* via mxrr, which the caller must free with dns_rr_free().
++/* Fallback from MX to address lookups is governed by RFC 2821,
++/* and by local policy (var_ign_mx_lookup_err).
+ /*
+ /* When no mail exchanger is listed in the DNS for \fIname\fR, the
+ /* request is passed to smtp_host_addr().
+@@ -44,8 +55,18 @@
+ /* host. The host can be specified as a numerical Internet network
+ /* address, or as a symbolic host name.
+ /*
+-/* Results from smtp_domain_addr() or smtp_host_addr() are
+-/* destroyed by dns_rr_free(), including null lists.
++/* smtp_service_addr() looks up addresses for hosts specified
++/* in SRV records for the specified domain and service. This
++/* supports the features of smtp_domain_addr() except that
++/* the order of SRV records is determined by RFC 2782, and
++/* that address records are not sorted by IP address family
++/* preference. Fallback from SRV to MX or address lookups is
++/* governed by local policy (var_ign_mx_lookup_err and
++/* var_allow_srv_fallback).
++/*
++/* Results from smtp_domain_addr(), smtp_host_addr(), and
++/* smtp_service_addr() are destroyed by dns_rr_free(), including
++/* null lists.
+ /* DIAGNOSTICS
+ /* Panics: interface violations. For example, calling smtp_domain_addr()
+ /* when DNS lookups are explicitly disabled.
+@@ -130,7 +151,8 @@ static void smtp_print_addr(const char *what, DNS_RR *addr_list)
+ /* smtp_addr_one - address lookup for one host name */
+
+ static DNS_RR *smtp_addr_one(DNS_RR *addr_list, const char *host, int res_opt,
+- unsigned pref, DSN_BUF *why)
++ unsigned pref, unsigned port,
++ DSN_BUF *why)
+ {
+ const char *myname = "smtp_addr_one";
+ DNS_RR *addr = 0;
+@@ -153,6 +175,8 @@ static DNS_RR *smtp_addr_one(DNS_RR *addr_list, const char *host, int res_opt,
+ if ((addr = dns_sa_to_rr(host, pref, res0->ai_addr)) == 0)
+ msg_fatal("host %s: conversion error for address family "
+ "%d: %m", host, res0->ai_addr->sa_family);
++ addr->pref = pref;
++ addr->port = port;
+ addr_list = dns_rr_append(addr_list, addr);
+ freeaddrinfo(res0);
+ return (addr_list);
+@@ -172,8 +196,10 @@ static DNS_RR *smtp_addr_one(DNS_RR *addr_list, const char *host, int res_opt,
+ why->reason, DNS_REQ_FLAG_NONE,
+ proto_info->dns_atype_list)) {
+ case DNS_OK:
+- for (rr = addr; rr; rr = rr->next)
++ for (rr = addr; rr; rr = rr->next) {
+ rr->pref = pref;
++ rr->port = port;
++ }
+ addr_list = dns_rr_append(addr_list, addr);
+ return (addr_list);
+ default:
+@@ -283,10 +309,10 @@ static DNS_RR *smtp_addr_list(DNS_RR *mx_names, DSN_BUF *why)
+ * tweaking the in-process resolver flags.
+ */
+ for (rr = mx_names; rr; rr = rr->next) {
+- if (rr->type != T_MX)
++ if (rr->type != T_MX && rr->type != T_SRV)
+ msg_panic("smtp_addr_list: bad resource type: %d", rr->type);
+ addr_list = smtp_addr_one(addr_list, (char *) rr->data, res_opt,
+- rr->pref, why);
++ rr->pref, rr->port, why);
+ }
+ return (addr_list);
+ }
+@@ -669,7 +695,7 @@ DNS_RR *smtp_host_addr(const char *host, int misc_flags, DSN_BUF *why)
+ * address to internal form. Otherwise, the host is specified by name.
+ */
+ #define PREF0 0
+- addr_list = smtp_addr_one((DNS_RR *) 0, ahost, res_opt, PREF0, why);
++ addr_list = smtp_addr_one((DNS_RR *) 0, ahost, res_opt, PREF0, 0, why);
+ if (addr_list
+ && (misc_flags & SMTP_MISC_FLAG_LOOP_DETECT)
+ && smtp_find_self(addr_list) != 0) {
+@@ -691,3 +717,135 @@ DNS_RR *smtp_host_addr(const char *host, int misc_flags, DSN_BUF *why)
+ smtp_print_addr(host, addr_list);
+ return (addr_list);
+ }
++
++/* smtp_service_addr - service address lookup */
++
++DNS_RR *smtp_service_addr(const char *name, const char *service, DNS_RR **mxrr,
++ int misc_flags, DSN_BUF *why,
++ int *found_myself)
++{
++ static VSTRING *srv_qname = 0;
++ const char *str_srv_qname;
++ DNS_RR *srv_names = 0;
++ DNS_RR *addr_list = 0;
++ DNS_RR *self = 0;
++ unsigned best_pref;
++ unsigned best_found;
++ int r = 0;
++ const char *aname;
++ int allow_non_srv_fallback = var_allow_srv_fallback;
++
++ dsb_reset(why);
++
++ /*
++ * Sanity check.
++ */
++ if (smtp_dns_support == SMTP_DNS_DISABLED)
++ msg_panic("smtp_service_addr: DNS lookup is disabled");
++
++ if (smtp_dns_support == SMTP_DNS_DNSSEC) {
++ r |= RES_USE_DNSSEC;
++ }
++ if (srv_qname == 0)
++ srv_qname = vstring_alloc(100);
++ vstring_sprintf(srv_qname, "_%s._tcp.%s", service, name);
++ str_srv_qname = STR(srv_qname);
++
++ /*
++ * IDNA support.
++ */
++#ifndef NO_EAI
++ if (!allascii(str_srv_qname)
++ && (aname = midna_domain_to_ascii(str_srv_qname)) != 0) {
++ if (msg_verbose)
++ msg_info("%s asciified to %s", str_srv_qname, aname);
++ } else
++#endif
++ aname = str_srv_qname;
++
++ switch (dns_lookup(aname, T_SRV, r, &srv_names, (VSTRING *) 0,
++ why->reason)) {
++ default:
++ dsb_status(why, "4.4.3");
++ allow_non_srv_fallback |= var_ign_srv_lookup_err;
++ break;
++ case DNS_INVAL:
++ dsb_status(why, "5.4.4");
++ allow_non_srv_fallback |= var_ign_srv_lookup_err;
++ break;
++ case DNS_POLICY:
++ dsb_status(why, "4.7.0");
++ break;
++ case DNS_FAIL:
++ dsb_status(why, "5.4.3");
++ allow_non_srv_fallback |= var_ign_srv_lookup_err;
++ break;
++ case DNS_NULLSRV:
++ dsb_status(why, "5.1.0");
++ break;
++ case DNS_OK:
++ /* Shuffle then sort the SRV rr records by priority and weight. */
++ srv_names = dns_srv_rr_sort(srv_names);
++ best_pref = (srv_names ? srv_names->pref : IMPOSSIBLE_PREFERENCE);
++ addr_list = smtp_addr_list(srv_names, why);
++ if (mxrr)
++ *mxrr = dns_rr_copy(srv_names); /* copies one record! */
++ dns_rr_free(srv_names);
++ if (addr_list == 0) {
++ msg_warn("no SRV host for %s has a valid address record",
++ str_srv_qname);
++ break;
++ }
++ /* Optional loop prevention, similar to smtp_domain_addr(). */
++ best_found = (addr_list ? addr_list->pref : IMPOSSIBLE_PREFERENCE);
++ if (msg_verbose)
++ smtp_print_addr(aname, addr_list);
++ if ((misc_flags & SMTP_MISC_FLAG_LOOP_DETECT)
++ && (self = smtp_find_self(addr_list)) != 0) {
++ addr_list = smtp_truncate_self(addr_list, self->pref);
++ if (addr_list == 0) {
++ if (best_pref != best_found) {
++ dsb_simple(why, "4.4.4",
++ "unable to find primary relay for %s",
++ str_srv_qname);
++ } else {
++ dsb_simple(why, "5.4.6", "mail for %s loops back to myself",
++ str_srv_qname);
++ }
++ }
++ }
++ /* TODO: sort by priority, weight, and address family preference. */
++
++ /* Optional address family balancing, as in smtp_domain_addr(). */
++ if (addr_list && addr_list->next) {
++ if (var_smtp_mxaddr_limit > 0 && var_smtp_balance_inet_proto)
++ addr_list = smtp_balance_inet_proto(addr_list, misc_flags,
++ var_smtp_mxaddr_limit);
++ }
++ break;
++ case DNS_NOTFOUND:
++ dsb_status(why, "5.4.4");
++ break;
++ }
++
++ /*
++ * If permitted, fall back to non-SRV record lookups.
++ */
++ if (addr_list == 0 && allow_non_srv_fallback) {
++ msg_info("skipping SRV lookup for %s: %s",
++ str_srv_qname, STR(why->reason));
++ if (misc_flags & SMTP_MISC_FLAG_FALLBACK_SRV_TO_MX)
++ addr_list = smtp_domain_addr(name, mxrr, misc_flags, why,
++ found_myself);
++ else
++ addr_list = smtp_host_addr(name, misc_flags, why);
++ }
++
++ /*
++ * Only if we're not falling back.
++ */
++ else {
++ *found_myself |= (self != 0);
++ }
++ return (addr_list);
++}
+diff --git a/src/smtp/smtp_addr.h b/src/smtp/smtp_addr.h
+index 8f20961..3d70413 100644
+--- a/src/smtp/smtp_addr.h
++++ b/src/smtp/smtp_addr.h
+@@ -18,6 +18,7 @@
+ */
+ extern DNS_RR *smtp_host_addr(const char *, int, DSN_BUF *);
+ extern DNS_RR *smtp_domain_addr(const char *, DNS_RR **, int, DSN_BUF *, int *);
++extern DNS_RR *smtp_service_addr(const char *, const char *, DNS_RR **, int, DSN_BUF *, int *);
+
+ /* LICENSE
+ /* .ad
+diff --git a/src/smtp/smtp_connect.c b/src/smtp/smtp_connect.c
+index 4d48883..4b3153f 100644
+--- a/src/smtp/smtp_connect.c
++++ b/src/smtp/smtp_connect.c
+@@ -28,7 +28,8 @@
+ /* destinations may be specified as "unix:pathname", "inet:host"
+ /* or "inet:host:port".
+ /*
+-/* With SMTP, the Internet domain name service is queried for mail
++/* With SMTP, or with SRV record lookup enabled, the Internet
++/* domain name service is queried for mail
+ /* exchanger hosts. Quote the domain name with `[' and `]' to
+ /* suppress mail exchanger lookups.
+ /*
+@@ -333,7 +334,8 @@ static SMTP_SESSION *smtp_connect_sock(int sock, struct sockaddr *sa,
+ /* smtp_parse_destination - parse host/port destination */
+
+ static char *smtp_parse_destination(char *destination, char *def_service,
+- char **hostp, unsigned *portp)
++ char **hostp, char **servicep,
++ unsigned *portp)
+ {
+ char *buf = mystrdup(destination);
+ char *service;
+@@ -349,12 +351,13 @@ static char *smtp_parse_destination(char *destination, char *def_service,
+ * Parse the host/port information. We're working with a copy of the
+ * destination argument so the parsing can be destructive.
+ */
+- if ((err = host_port(buf, hostp, (char *) 0, &service, def_service)) != 0)
++ if ((err = host_port(buf, hostp, (char *) 0, servicep, def_service)) != 0)
+ msg_fatal("%s in server description: %s", err, destination);
+
+ /*
+ * Convert service to port number, network byte order.
+ */
++ service = *servicep;
+ if (alldig(service)) {
+ if ((port = atoi(service)) >= 65536 || port == 0)
+ msg_fatal("bad network port in destination: %s", destination);
+@@ -635,6 +638,9 @@ static void smtp_update_addr_list(DNS_RR **addr_list, const char *server_addr,
+ * XXX Extend the SMTP_SESSION structure with sockaddr information so that
+ * we can avoid repeated string->binary transformations for the same
+ * address.
++ *
++ * XXX SRV support: this should match the port, too, otherwise we may
++ * eliminate too many list entries.
+ */
+ if ((aierr = hostaddr_to_sockaddr(server_addr, (char *) 0, 0, &res0)) != 0) {
+ msg_warn("hostaddr_to_sockaddr %s: %s",
+@@ -665,6 +671,18 @@ static int smtp_reuse_session(SMTP_STATE *state, DNS_RR **addr_list,
+ DSN_BUF *why = state->why;
+
+ /*
++ * This code is called after server address/port lookup, before
++ * iter->host, iter->addr, iter->rr and iter->mx are assigned concrete
++ * values, and while iter->port still corresponds to the nexthop service,
++ * or the default service configured with smtp_tcp_port or lmtp_tcp_port.
++ *
++ * When a connection is reused by nexthop/service or by server address/port,
++ * iter->host, iter->addr and iter->port are updated with actual values
++ * from the cached session. Additionally, when a connection is searched
++ * by nexthop/service, iter->rr remains null, and when a connection is
++ * searched by server address/port, iter->rr is updated with an actual
++ * server address/port before the search is made.
++ *
+ * First, search the cache by delivery request nexthop. We truncate the
+ * server address list when all the sessions for this destination are
+ * used up, to reduce the number of variables that need to be checked
+@@ -731,9 +749,7 @@ static int smtp_reuse_session(SMTP_STATE *state, DNS_RR **addr_list,
+ /* XXX Assume there is no code at the end of this loop. */
+ continue;
+ }
+- vstring_strcpy(iter->addr, hostaddr.buf);
+- vstring_strcpy(iter->host, SMTP_HNAME(addr));
+- iter->rr = addr;
++ SMTP_ITER_UPDATE_HOST(iter, SMTP_HNAME(addr), hostaddr.buf, addr);
+ #ifdef USE_TLS
+ if (!smtp_tls_policy_cache_query(why, state->tls, iter)) {
+ msg_warn("TLS policy lookup error for %s/%s: %s",
+@@ -818,6 +834,7 @@ static void smtp_connect_inet(SMTP_STATE *state, const char *nexthop,
+ char *dest_buf;
+ char *domain;
+ unsigned port;
++ char *service;
+ DNS_RR *addr_list;
+ DNS_RR *addr;
+ DNS_RR *next;
+@@ -825,6 +842,8 @@ static void smtp_connect_inet(SMTP_STATE *state, const char *nexthop,
+ int sess_count;
+ SMTP_SESSION *session;
+ int lookup_mx;
++ int non_dns_or_literal;
++ int i_am_mx;
+ unsigned domain_best_pref;
+ MAI_HOSTADDR_STR hostaddr;
+
+@@ -834,8 +853,28 @@ static void smtp_connect_inet(SMTP_STATE *state, const char *nexthop,
+ /*
+ * Parse the destination. If no TCP port is specified, use the port
+ * that is reserved for the protocol (SMTP or LMTP).
++ *
++ * The 'service' variable corresponds to the remote service specified
++ * with the nexthop, or the default service configured with
++ * smtp_tcp_port or lmtp_tcp_port. The 'port' variable and
++ * SMTP_ITERATOR.port initially correspond to that service. This
++ * determines what loop prevention will be in effect.
++ *
++ * The SMTP_ITERATOR.port will be overwritten after SRV record lookup.
++ * This guarantees that the connection cache key contains the correct
++ * port value when caching and retrieving a connection by its server
++ * address (and port).
++ *
++ * By design, the connection cache key contains NO port information when
++ * caching or retrieving a connection by its nexthop destination.
++ * Instead, the cache key contains the master.cf service name (a
++ * proxy for all the parameter settings including the default service
++ * from smtp_tcp_port or lmtp_tcp_port), together with the nexthop
++ * destination and sender-dependent info. This should be sufficient
++ * to avoid cross talk between mail streams that should be separated.
+ */
+- dest_buf = smtp_parse_destination(dest, def_service, &domain, &port);
++ dest_buf = smtp_parse_destination(dest, def_service, &domain,
++ &service, &port);
+ if (var_helpful_warnings && var_smtp_tls_wrappermode == 0
+ && ntohs(port) == 465) {
+ msg_info("SMTPS wrappermode (TCP port 465) requires setting "
+@@ -848,32 +887,48 @@ static void smtp_connect_inet(SMTP_STATE *state, const char *nexthop,
+ SMTP_ITER_INIT(iter, dest, NO_HOST, NO_ADDR, port, state);
+
+ /*
+- * Resolve an SMTP or LMTP server. In the case of SMTP, skip mail
+- * exchanger lookups when a quoted host is specified or when DNS
+- * lookups are disabled.
++ * Resolve an SMTP or LMTP server. Skip MX or SRV lookups when a
++ * quoted domain is specified or when DNS lookups are disabled.
+ */
+ if (msg_verbose)
+- msg_info("connecting to %s port %d", domain, ntohs(port));
++ msg_info("connecting to %s service %s", domain, service);
++ non_dns_or_literal = (smtp_dns_support == SMTP_DNS_DISABLED
++ || *dest == '[');
+ if (smtp_mode) {
+ if (ntohs(port) == IPPORT_SMTP)
+ state->misc_flags |= SMTP_MISC_FLAG_LOOP_DETECT;
+ else
+ state->misc_flags &= ~SMTP_MISC_FLAG_LOOP_DETECT;
+- lookup_mx = (smtp_dns_support != SMTP_DNS_DISABLED && *dest != '[');
++ lookup_mx = !non_dns_or_literal;
+ } else
+ lookup_mx = 0;
+- if (!lookup_mx) {
++
++ /*
++ * Look up SRV and address records and fall back to non-SRV lookups
++ * if permitted by configuration settings, or look up MX and address
++ * records, or look up address records only.
++ */
++ i_am_mx = 0;
++ addr_list = 0;
++ if (!non_dns_or_literal && smtp_use_srv_lookup
++ && string_list_match(smtp_use_srv_lookup, service)) {
++ if (lookup_mx)
++ state->misc_flags |= SMTP_MISC_FLAG_FALLBACK_SRV_TO_MX;
++ else
++ state->misc_flags &= ~SMTP_MISC_FLAG_FALLBACK_SRV_TO_MX;
++ addr_list = smtp_service_addr(domain, service, &iter->mx,
++ state->misc_flags, why, &i_am_mx);
++ } else if (!lookup_mx) {
++ /* Non-DNS, literal, or non-SMTP service */
+ addr_list = smtp_host_addr(domain, state->misc_flags, why);
+ /* XXX We could be an MX host for this destination... */
+ } else {
+- int i_am_mx = 0;
+-
+ addr_list = smtp_domain_addr(domain, &iter->mx, state->misc_flags,
+ why, &i_am_mx);
+- /* If we're MX host, don't connect to non-MX backups. */
+- if (i_am_mx)
+- state->misc_flags |= SMTP_MISC_FLAG_FINAL_NEXTHOP;
+ }
++ /* If we're MX host, don't connect to non-MX backups. */
++ if (i_am_mx)
++ state->misc_flags |= SMTP_MISC_FLAG_FINAL_NEXTHOP;
+
+ /*
+ * Don't try fall-back hosts if mail loops to myself. That would just
+@@ -966,9 +1021,7 @@ static void smtp_connect_inet(SMTP_STATE *state, const char *nexthop,
+ /* XXX Assume there is no code at the end of this loop. */
+ continue;
+ }
+- vstring_strcpy(iter->addr, hostaddr.buf);
+- vstring_strcpy(iter->host, SMTP_HNAME(addr));
+- iter->rr = addr;
++ SMTP_ITER_UPDATE_HOST(iter, SMTP_HNAME(addr), hostaddr.buf, addr);
+ #ifdef USE_TLS
+ if (!smtp_tls_policy_cache_query(why, state->tls, iter)) {
+ msg_warn("TLS policy lookup for %s/%s: %s",
+diff --git a/src/smtp/smtp_params.c b/src/smtp/smtp_params.c
+index 561f6a0..b893a76 100644
+--- a/src/smtp/smtp_params.c
++++ b/src/smtp/smtp_params.c
+@@ -65,6 +65,7 @@
+ VAR_SMTP_DSN_FILTER, DEF_SMTP_DSN_FILTER, &var_smtp_dsn_filter, 0, 0,
+ VAR_SMTP_DNS_RE_FILTER, DEF_SMTP_DNS_RE_FILTER, &var_smtp_dns_re_filter, 0, 0,
+ VAR_TLSPROXY_SERVICE, DEF_TLSPROXY_SERVICE, &var_tlsproxy_service, 1, 0,
++ VAR_USE_SRV_LOOKUP, DEF_USE_SRV_LOOKUP, &var_use_srv_lookup, 0, 0,
+ 0,
+ };
+ static const CONFIG_TIME_TABLE smtp_time_table[] = {
+@@ -130,5 +131,7 @@
+ VAR_SMTP_REC_DEADLINE, DEF_SMTP_REC_DEADLINE, &var_smtp_rec_deadline,
+ VAR_SMTP_DUMMY_MAIL_AUTH, DEF_SMTP_DUMMY_MAIL_AUTH, &var_smtp_dummy_mail_auth,
+ VAR_SMTP_BALANCE_INET_PROTO, DEF_SMTP_BALANCE_INET_PROTO, &var_smtp_balance_inet_proto,
++ VAR_IGN_SRV_LOOKUP_ERR, DEF_IGN_SRV_LOOKUP_ERR, &var_ign_srv_lookup_err,
++ VAR_ALLOW_SRV_FALLBACK, DEF_ALLOW_SRV_FALLBACK, &var_allow_srv_fallback,
+ 0,
+ };
+diff --git a/src/smtp/smtp_session.c b/src/smtp/smtp_session.c
+index 1b3a20e..3ac4ccc 100644
+--- a/src/smtp/smtp_session.c
++++ b/src/smtp/smtp_session.c
+@@ -129,6 +129,7 @@
+ #define SESS_ATTR_DEST "destination"
+ #define SESS_ATTR_HOST "host_name"
+ #define SESS_ATTR_ADDR "host_addr"
++#define SESS_ATTR_PORT "host_port"
+ #define SESS_ATTR_DEST_FEATURES "destination_features"
+
+ #define SESS_ATTR_TLS_LEVEL "tls_level"
+@@ -258,6 +259,7 @@ int smtp_session_passivate(SMTP_SESSION *session, VSTRING *dest_prop,
+ SEND_ATTR_STR(SESS_ATTR_DEST, STR(iter->dest)),
+ SEND_ATTR_STR(SESS_ATTR_HOST, STR(iter->host)),
+ SEND_ATTR_STR(SESS_ATTR_ADDR, STR(iter->addr)),
++ SEND_ATTR_UINT(SESS_ATTR_PORT, iter->port),
+ SEND_ATTR_INT(SESS_ATTR_DEST_FEATURES,
+ session->features & SMTP_FEATURE_DESTINATION_MASK),
+ ATTR_TYPE_END) != 0
+@@ -397,9 +399,10 @@ SMTP_SESSION *smtp_session_activate(int fd, SMTP_ITERATOR *iter,
+ RECV_ATTR_STR(SESS_ATTR_DEST, iter->dest),
+ RECV_ATTR_STR(SESS_ATTR_HOST, iter->host),
+ RECV_ATTR_STR(SESS_ATTR_ADDR, iter->addr),
++ RECV_ATTR_UINT(SESS_ATTR_PORT, &iter->port),
+ RECV_ATTR_INT(SESS_ATTR_DEST_FEATURES,
+ &dest_features),
+- ATTR_TYPE_END) != 4
++ ATTR_TYPE_END) != 5
+ || vstream_fclose(mp) != 0) {
+ msg_warn("smtp_session_passivate: bad cached dest properties");
+ SMTP_SESSION_ACTIVATE_ERR_RETURN();
+diff --git a/src/smtpd/smtpd_check.c b/src/smtpd/smtpd_check.c
+index 85d5944..a60e878 100644
+--- a/src/smtpd/smtpd_check.c
++++ b/src/smtpd/smtpd_check.c
+@@ -3056,8 +3056,8 @@ static int check_server_access(SMTPD_STATE *state, const char *table,
+ || type == T_AAAA
+ #endif
+ ) {
+- server_list = dns_rr_create(domain, domain, T_MX, C_IN, 0, 0,
+- domain, strlen(domain) + 1);
++ server_list = dns_rr_create_nopref(domain, domain, T_MX, C_IN, 0,
++ domain, strlen(domain) + 1);
+ } else {
+ dns_status = dns_lookup(domain, type, 0, &server_list,
+ (VSTRING *) 0, (VSTRING *) 0);
+@@ -3065,8 +3065,8 @@ static int check_server_access(SMTPD_STATE *state, const char *table,
+ return (SMTPD_CHECK_DUNNO);
+ if (dns_status == DNS_NOTFOUND /* Not: h_errno == NO_DATA */ ) {
+ if (type == T_MX) {
+- server_list = dns_rr_create(domain, domain, type, C_IN, 0, 0,
+- domain, strlen(domain) + 1);
++ server_list = dns_rr_create_nopref(domain, domain, type, C_IN,
++ 0, domain, strlen(domain) + 1);
+ dns_status = DNS_OK;
+ } else if (type == T_NS /* && h_errno == NO_DATA */ ) {
+ while ((domain = strchr(domain, '.')) != 0 && domain[1]) {
+diff --git a/src/util/attr.h b/src/util/attr.h
+index dc6f9f7..a890a5b 100644
+--- a/src/util/attr.h
++++ b/src/util/attr.h
+@@ -61,6 +61,7 @@ typedef int (*ATTR_PRINT_SLAVE_FN) (ATTR_PRINT_MASTER_FN, VSTREAM *, int, void *
+ * for documentation.
+ */
+ #define SEND_ATTR_INT(name, val) ATTR_TYPE_INT, CHECK_CPTR(ATTR, char, (name)), CHECK_VAL(ATTR, int, (val))
++#define SEND_ATTR_UINT(name, val) ATTR_TYPE_INT, CHECK_CPTR(ATTR, char, (name)), CHECK_VAL(ATTR, unsigned, (val))
+ #define SEND_ATTR_STR(name, val) ATTR_TYPE_STR, CHECK_CPTR(ATTR, char, (name)), CHECK_CPTR(ATTR, char, (val))
+ #define SEND_ATTR_HASH(val) ATTR_TYPE_HASH, CHECK_CPTR(ATTR, HTABLE, (val))
+ #define SEND_ATTR_NV(val) ATTR_TYPE_NV, CHECK_CPTR(ATTR, NVTABLE, (val))
+@@ -69,6 +70,7 @@ typedef int (*ATTR_PRINT_SLAVE_FN) (ATTR_PRINT_MASTER_FN, VSTREAM *, int, void *
+ #define SEND_ATTR_FUNC(func, val) ATTR_TYPE_FUNC, CHECK_VAL(ATTR, ATTR_PRINT_SLAVE_FN, (func)), CHECK_CPTR(ATTR, void, (val))
+
+ #define RECV_ATTR_INT(name, val) ATTR_TYPE_INT, CHECK_CPTR(ATTR, char, (name)), CHECK_PTR(ATTR, int, (val))
++#define RECV_ATTR_UINT(name, val) ATTR_TYPE_INT, CHECK_CPTR(ATTR, char, (name)), CHECK_PTR(ATTR, unsigned, (val))
+ #define RECV_ATTR_STR(name, val) ATTR_TYPE_STR, CHECK_CPTR(ATTR, char, (name)), CHECK_PTR(ATTR, VSTRING, (val))
+ #define RECV_ATTR_HASH(val) ATTR_TYPE_HASH, CHECK_PTR(ATTR, HTABLE, (val))
+ #define RECV_ATTR_NV(val) ATTR_TYPE_NV, CHECK_PTR(ATTR, NVTABLE, (val))
+@@ -79,9 +81,11 @@ typedef int (*ATTR_PRINT_SLAVE_FN) (ATTR_PRINT_MASTER_FN, VSTREAM *, int, void *
+ CHECK_VAL_HELPER_DCL(ATTR, ssize_t);
+ CHECK_VAL_HELPER_DCL(ATTR, long);
+ CHECK_VAL_HELPER_DCL(ATTR, int);
++CHECK_VAL_HELPER_DCL(ATTR, unsigned);
+ CHECK_PTR_HELPER_DCL(ATTR, void);
+ CHECK_PTR_HELPER_DCL(ATTR, long);
+ CHECK_PTR_HELPER_DCL(ATTR, int);
++CHECK_PTR_HELPER_DCL(ATTR, unsigned);
+ CHECK_PTR_HELPER_DCL(ATTR, VSTRING);
+ CHECK_PTR_HELPER_DCL(ATTR, NVTABLE);
+ CHECK_PTR_HELPER_DCL(ATTR, HTABLE);
diff --git a/postfix-3.5.9-makedefs.patch b/postfix-3.5.9-makedefs.patch
new file mode 100644
index 0000000..24b0ea5
--- /dev/null
+++ b/postfix-3.5.9-makedefs.patch
@@ -0,0 +1,32 @@
+commit 9c7bcf991e2dd69d517be84d9594411c47e04562
+Author: Tomas Korbar
+Date: Fri May 5 12:48:21 2023 +0200
+
+ Fix build with kernel 6
+
+diff --git a/makedefs b/makedefs
+index aea15d6..ad93a5f 100644
+--- a/makedefs
++++ b/makedefs
+@@ -557,7 +557,7 @@ EOF
+ : ${SHLIB_ENV="LD_LIBRARY_PATH=`pwd`/lib"}
+ : ${PLUGIN_LD="${CC-gcc} -shared"}
+ ;;
+- Linux.[345].*) SYSTYPE=LINUX$RELEASE_MAJOR
++ Linux.[3456].*) SYSTYPE=LINUX$RELEASE_MAJOR
+ case "$CCARGS" in
+ *-DNO_DB*) ;;
+ *-DHAS_DB*) ;;
+diff --git a/src/util/sys_defs.h b/src/util/sys_defs.h
+index f3a3b26..e9d3546 100644
+--- a/src/util/sys_defs.h
++++ b/src/util/sys_defs.h
+@@ -749,7 +749,7 @@ extern int initgroups(const char *, int);
+ /*
+ * LINUX.
+ */
+-#if defined(LINUX2) || defined(LINUX3) || defined(LINUX4) || defined(LINUX5)
++#if defined(LINUX2) || defined(LINUX3) || defined(LINUX4) || defined(LINUX5) || defined(LINUX6)
+ #define SUPPORTED
+ #define UINT32_TYPE unsigned int
+ #define UINT16_TYPE unsigned short
diff --git a/postfix.spec b/postfix.spec
index 6668046..67fbe7a 100644
--- a/postfix.spec
+++ b/postfix.spec
@@ -49,7 +49,7 @@
Name: postfix
Summary: Postfix Mail Transport Agent
Version: 3.5.9
-Release: 19%{?dist}
+Release: 20%{?dist}
Epoch: 2
URL: http://www.postfix.org
License: (IBM and GPLv2+) or (EPL-2.0 and GPLv2+)
@@ -106,6 +106,10 @@ Patch13: postfix-3.5.9-whitespace-name-fix.patch
Patch14: pflogsumm-1.1.5-syslog-name-underscore-fix.patch
# rhbz#1938847, backported from upstream
Patch15: postfix-3.5.9-coverity-fix.patch
+# rhbz#2134789, backported feature from upstream
+Patch16: postfix-3.5.9-SRV-resolve.patch
+# rhbz#2193363 ZUUL CI uses kernel 6 and we have to add this to postfix
+Patch17: postfix-3.5.9-makedefs.patch
# Optional patches - set the appropriate environment variables to include
# them when building the package/spec file
@@ -260,6 +264,8 @@ popd
%patch13 -p1 -b .whitespace-name-fix
%patch14 -p1 -b .pflogsumm-1.1.5-syslog-name-underscore-fix
%patch15 -p1 -b .coverity-fix
+%patch16 -p1 -b .SRV-resolution
+%patch17 -p1 -b .makedefs
for f in README_FILES/TLS_{LEGACY_,}README TLS_ACKNOWLEDGEMENTS; do
iconv -f iso8859-1 -t utf8 -o ${f}{_,} &&
@@ -803,6 +809,12 @@ fi
%endif
%changelog
+* Thu May 04 2023 Tomas Korbar - 2:3.5.9-20
+- Backport dns SRV record resolution feature (RFC6186)
+ Resolves: rhbz#2134789
+- Fix building in ZUUL CI
+ Resolves: rhbz#2193363
+
* Fri Aug 19 2022 Jaroslav Škarvada - 2:3.5.9-19
- Suppressed openssl output during SSL certificates generation
Resolves: rhbz#2041589