resolved: move packet rewinder initalization inline

There is no functional change, but this reduces the risk that
in some future refactoring we'll forget the do the initialization in all
execution paths.

diff --git a/src/resolve/resolved-dns-packet.c b/src/resolve/resolved-dns-packet.c
index b37f57fe676a7ed3708a9dfc18aca669f9cc14a8..a9648648037c006e46fcb361ae2fea257be99434 100644 (file)
--- a/src/resolve/resolved-dns-packet.c
+++ b/src/resolve/resolved-dns-packet.c
@@ -29,8 +29,11 @@ static void rewind_dns_packet(DnsPacketRewinder *rewinder) {
                 dns_packet_rewind(rewinder->packet, rewinder->saved_rindex);
 }
 
-#define INIT_REWINDER(rewinder, p) do { rewinder.packet = p; rewinder.saved_rindex = p->rindex; } while (0)
-#define CANCEL_REWINDER(rewinder) do { rewinder.packet = NULL; } while (0)
+#define REWINDER_INIT(p) {                              \
+                .packet = (p),                          \
+                .saved_rindex = (p)->rindex,            \
+        }
+#define CANCEL_REWINDER(rewinder) do { (rewinder).packet = NULL; } while (0)
 
 int dns_packet_new(
                 DnsPacket **ret,
@@ -1373,15 +1376,14 @@ int dns_packet_read_uint32(DnsPacket *p, uint32_t *ret, size_t *start) {
 }
 
 int dns_packet_read_string(DnsPacket *p, char **ret, size_t *start) {
-        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder;
+        assert(p);
+
+        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder = REWINDER_INIT(p);
         const void *d;
         char *t;
         uint8_t c;
         int r;
 
-        assert(p);
-        INIT_REWINDER(rewinder, p);
-
         r = dns_packet_read_uint8(p, &c, NULL);
         if (r < 0)
                 return r;
@@ -1412,13 +1414,12 @@ int dns_packet_read_string(DnsPacket *p, char **ret, size_t *start) {
 }
 
 int dns_packet_read_raw_string(DnsPacket *p, const void **ret, size_t *size, size_t *start) {
-        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder;
+        assert(p);
+
+        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder = REWINDER_INIT(p);
         uint8_t c;
         int r;
 
-        assert(p);
-        INIT_REWINDER(rewinder, p);
-
         r = dns_packet_read_uint8(p, &c, NULL);
         if (r < 0)
                 return r;
@@ -1442,18 +1443,15 @@ int dns_packet_read_name(
                 bool allow_compression,
                 size_t *ret_start) {
 
-        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder;
-        size_t after_rindex = 0, jump_barrier;
+        assert(p);
+
+        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder = REWINDER_INIT(p);
+        size_t after_rindex = 0, jump_barrier = p->rindex;
         _cleanup_free_ char *name = NULL;
         bool first = true;
         size_t n = 0;
         int r;
 
-        assert(p);
-
-        INIT_REWINDER(rewinder, p);
-        jump_barrier = p->rindex;
-
         if (p->refuse_compression)
                 allow_compression = false;
 
@@ -1530,19 +1528,17 @@ int dns_packet_read_name(
 }
 
 static int dns_packet_read_type_window(DnsPacket *p, Bitmap **types, size_t *start) {
-        uint8_t window;
-        uint8_t length;
+        assert(p);
+        assert(types);
+
+        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder = REWINDER_INIT(p);
+        uint8_t window, length;
         const uint8_t *bitmap;
         uint8_t bit = 0;
         unsigned i;
         bool found = false;
-        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder;
         int r;
 
-        assert(p);
-        assert(types);
-        INIT_REWINDER(rewinder, p);
-
         r = bitmap_ensure_allocated(types);
         if (r < 0)
                 return r;
@@ -1600,11 +1596,9 @@ static int dns_packet_read_type_window(DnsPacket *p, Bitmap **types, size_t *sta
 }
 
 static int dns_packet_read_type_windows(DnsPacket *p, Bitmap **types, size_t size, size_t *start) {
-        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder;
+        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder = REWINDER_INIT(p);
         int r;
 
-        INIT_REWINDER(rewinder, p);
-
         while (p->rindex < rewinder.saved_rindex + size) {
                 r = dns_packet_read_type_window(p, types, NULL);
                 if (r < 0)
@@ -1631,15 +1625,14 @@ int dns_packet_read_key(
                 bool *ret_cache_flush_or_qu,
                 size_t *ret_start) {
 
-        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder;
+        assert(p);
+
+        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder = REWINDER_INIT(p);
         _cleanup_free_ char *name = NULL;
         bool cache_flush_or_qu = false;
         uint16_t class, type;
         int r;
 
-        assert(p);
-        INIT_REWINDER(rewinder, p);
-
         r = dns_packet_read_name(p, &name, true, NULL);
         if (r < 0)
                 return r;
@@ -1693,18 +1686,16 @@ int dns_packet_read_rr(
                 bool *ret_cache_flush,
                 size_t *ret_start) {
 
+        assert(p);
+
+        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder = REWINDER_INIT(p);
         _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
         _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
-        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder;
         size_t offset;
         uint16_t rdlength;
         bool cache_flush;
         int r;
 
-        assert(p);
-
-        INIT_REWINDER(rewinder, p);
-
         r = dns_packet_read_key(p, &key, &cache_flush, NULL);
         if (r < 0)
                 return r;
@@ -2390,15 +2381,16 @@ static int dns_packet_extract_answer(DnsPacket *p, DnsAnswer **ret_answer) {
 }
 
 int dns_packet_extract(DnsPacket *p) {
-        _cleanup_(dns_question_unrefp) DnsQuestion *question = NULL;
-        _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
-        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder = {};
-        int r;
+        assert(p);
 
         if (p->extracted)
                 return 0;
 
-        INIT_REWINDER(rewinder, p);
+        _cleanup_(dns_question_unrefp) DnsQuestion *question = NULL;
+        _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
+        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder = REWINDER_INIT(p);
+        int r;
+
         dns_packet_rewind(p, DNS_PACKET_HEADER_SIZE);
 
         r = dns_packet_extract_question(p, &question);
@@ -2417,7 +2409,6 @@ int dns_packet_extract(DnsPacket *p) {
 
         p->question = TAKE_PTR(question);
         p->answer = TAKE_PTR(answer);
-
         p->extracted = true;
 
         /* no CANCEL, always rewind */
@@ -2466,14 +2457,12 @@ int dns_packet_patch_max_udp_size(DnsPacket *p, uint16_t max_udp_size) {
 }
 
 static int patch_rr(DnsPacket *p, usec_t age) {
-        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder;
+        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder = REWINDER_INIT(p);
         size_t ttl_index;
         uint32_t ttl;
         uint16_t type, rdlength;
         int r;
 
-        INIT_REWINDER(rewinder, p);
-
         /* Patches the RR at the current rindex, subtracts the specified time from the TTL */
 
         r = dns_packet_read_name(p, NULL, true, NULL);
@@ -2510,22 +2499,20 @@ static int patch_rr(DnsPacket *p, usec_t age) {
 }
 
 int dns_packet_patch_ttls(DnsPacket *p, usec_t timestamp) {
-        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder = {};
-        unsigned i, n;
-        usec_t k;
-        int r;
-
         assert(p);
         assert(timestamp_is_set(timestamp));
 
         /* Adjusts all TTLs in the packet by subtracting the time difference between now and the specified timestamp */
 
+        _cleanup_(rewind_dns_packet) DnsPacketRewinder rewinder = REWINDER_INIT(p);
+        unsigned i, n;
+        usec_t k;
+        int r;
+
         k = now(clock_boottime_or_monotonic());
         assert(k >= timestamp);
         k -= timestamp;
 
-        INIT_REWINDER(rewinder, p);
-
         dns_packet_rewind(p, DNS_PACKET_HEADER_SIZE);
 
         n = DNS_PACKET_QDCOUNT(p);