resolved: make TXT RR generation and parsing more in-line with RFC 6763, section 6.1

[elogind.git] / src / libsystemd-network / dhcp6-option.c

diff --git a/src/libsystemd-network/dhcp6-option.c b/src/libsystemd-network/dhcp6-option.c
index e6a31778f47a7c3e68ddf1b3f5e74d3bb9e1ad12..ea863f45e4ea13a400461949a62cbce71c913379 100644 (file)
--- a/src/libsystemd-network/dhcp6-option.c
+++ b/src/libsystemd-network/dhcp6-option.c
@@ -24,31 +24,37 @@
 #include <string.h>
 
 #include "sparse-endian.h"
+#include "unaligned.h"
 #include "util.h"
 
 #include "dhcp6-internal.h"
 #include "dhcp6-protocol.h"
 
-#define DHCP6_OPTION_HDR_LEN                    4
 #define DHCP6_OPTION_IA_NA_LEN                  12
 #define DHCP6_OPTION_IA_TA_LEN                  4
 
+typedef struct DHCP6Option {
+        be16_t code;
+        be16_t len;
+        uint8_t data[];
+} _packed_ DHCP6Option;
+
 static int option_append_hdr(uint8_t **buf, size_t *buflen, uint16_t optcode,
                              size_t optlen) {
+        DHCP6Option *option = (DHCP6Option*) *buf;
+
         assert_return(buf, -EINVAL);
         assert_return(*buf, -EINVAL);
         assert_return(buflen, -EINVAL);
 
-        if (optlen > 0xffff || *buflen < optlen + DHCP6_OPTION_HDR_LEN)
+        if (optlen > 0xffff || *buflen < optlen + sizeof(DHCP6Option))
                 return -ENOBUFS;
 
-        (*buf)[0] = optcode >> 8;
-        (*buf)[1] = optcode & 0xff;
-        (*buf)[2] = optlen >> 8;
-        (*buf)[3] = optlen & 0xff;
+        option->code = htobe16(optcode);
+        option->len = htobe16(optlen);
 
-        *buf += DHCP6_OPTION_HDR_LEN;
-        *buflen -= DHCP6_OPTION_HDR_LEN;
+        *buf += sizeof(DHCP6Option);
+        *buflen -= sizeof(DHCP6Option);
 
         return 0;
 }
@@ -100,8 +106,8 @@ int dhcp6_option_append_ia(uint8_t **buf, size_t *buflen, DHCP6IA *ia) {
         ia_hdr = *buf;
         ia_buflen = *buflen;
 
-        *buf += DHCP6_OPTION_HDR_LEN;
-        *buflen -= DHCP6_OPTION_HDR_LEN;
+        *buf += sizeof(DHCP6Option);
+        *buflen -= sizeof(DHCP6Option);
 
         memcpy(*buf, &ia->id, len);
 
@@ -119,7 +125,7 @@ int dhcp6_option_append_ia(uint8_t **buf, size_t *buflen, DHCP6IA *ia) {
                 *buf += sizeof(addr->iaaddr);
                 *buflen -= sizeof(addr->iaaddr);
 
-                ia_addrlen += DHCP6_OPTION_HDR_LEN + sizeof(addr->iaaddr);
+                ia_addrlen += sizeof(DHCP6Option) + sizeof(addr->iaaddr);
         }
 
         r = option_append_hdr(&ia_hdr, &ia_buflen, ia->type, len + ia_addrlen);
@@ -130,23 +136,23 @@ int dhcp6_option_append_ia(uint8_t **buf, size_t *buflen, DHCP6IA *ia) {
 }
 
 
-static int option_parse_hdr(uint8_t **buf, size_t *buflen, uint16_t *opt,
-                            size_t *optlen) {
+static int option_parse_hdr(uint8_t **buf, size_t *buflen, uint16_t *optcode, size_t *optlen) {
+        DHCP6Option *option = (DHCP6Option*) *buf;
         uint16_t len;
 
         assert_return(buf, -EINVAL);
-        assert_return(opt, -EINVAL);
+        assert_return(optcode, -EINVAL);
         assert_return(optlen, -EINVAL);
 
-        if (*buflen < 4)
+        if (*buflen < sizeof(DHCP6Option))
                 return -ENOMSG;
 
-        len = (*buf)[2] << 8 | (*buf)[3];
+        len = be16toh(option->len);
 
         if (len > *buflen)
                 return -ENOMSG;
 
-        *opt = (*buf)[0] << 8 | (*buf)[1];
+        *optcode = be16toh(option->code);
         *optlen = len;
 
         *buf += 4;
@@ -190,7 +196,7 @@ int dhcp6_option_parse_ia(uint8_t **buf, size_t *buflen, uint16_t iatype,
         switch (iatype) {
         case DHCP6_OPTION_IA_NA:
 
-                if (*buflen < DHCP6_OPTION_IA_NA_LEN + DHCP6_OPTION_HDR_LEN +
+                if (*buflen < DHCP6_OPTION_IA_NA_LEN + sizeof(DHCP6Option) +
                     sizeof(addr->iaaddr)) {
                         r = -ENOBUFS;
                         goto error;
@@ -212,7 +218,7 @@ int dhcp6_option_parse_ia(uint8_t **buf, size_t *buflen, uint16_t iatype,
                 break;
 
         case DHCP6_OPTION_IA_TA:
-                if (*buflen < DHCP6_OPTION_IA_TA_LEN + DHCP6_OPTION_HDR_LEN +
+                if (*buflen < DHCP6_OPTION_IA_TA_LEN + sizeof(DHCP6Option) +
                     sizeof(addr->iaaddr)) {
                         r = -ENOBUFS;
                         goto error;