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feature: support set ttl, ttl-min, ttl-max to domain.

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This commit is contained in:
Nick Peng
2023-02-14 22:46:15 +08:00
parent db56472b84
commit 499ab1b64f
6 changed files with 134 additions and 33 deletions
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35
src/dns.c
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@@ -42,6 +42,8 @@
(void)(expr); \
} while (0)
#define member_size(type, member) sizeof(((type *)0)->member)
/* read short and move pointer */
static unsigned short _dns_read_short(unsigned char **buffer)
{
@@ -111,7 +113,7 @@ static int _dns_get_domain_from_packet(unsigned char *packet, int packet_size, u
/*[len]string[len]string...[0]0 */
while (1) {
if (ptr >= packet + packet_size || ptr < packet || output_len >= size - 1 || ptr_jump > 4) {
if (ptr >= packet + packet_size || ptr < packet || output_len >= size - 1 || ptr_jump > 32) {
return -1;
}
@@ -1639,12 +1641,12 @@ static int _dns_encode_SOA(struct dns_context *context, struct dns_rrs *rrs)
return 0;
}
static int _dns_decode_opt_ecs(struct dns_context *context, struct dns_opt_ecs *ecs)
static int _dns_decode_opt_ecs(struct dns_context *context, struct dns_opt_ecs *ecs, int opt_len)
{
// TODO
int len = 0;
if (_dns_left_len(context) < 4) {
if (opt_len < 4) {
return -1;
}
@@ -1668,25 +1670,24 @@ static int _dns_decode_opt_ecs(struct dns_context *context, struct dns_opt_ecs *
return 0;
}
static int _dns_decode_opt_cookie(struct dns_context *context, struct dns_opt_cookie *cookie)
static int _dns_decode_opt_cookie(struct dns_context *context, struct dns_opt_cookie *cookie, int opt_len)
{
// TODO
int len = _dns_left_len(context);
if (len < 8) {
if (opt_len < (int)member_size(struct dns_opt_cookie, client_cookie)) {
return -1;
}
len = 8;
int len = 8;
memcpy(cookie->client_cookie, context->ptr, len);
context->ptr += len;
len = _dns_left_len(context);
if (len == 0) {
opt_len -= len;
if (opt_len <= 0) {
cookie->server_cookie_len = 0;
return 0;
}
if (len < 8) {
if (opt_len < (int)member_size(struct dns_opt_cookie, server_cookie)) {
return -1;
}
@@ -1881,7 +1882,7 @@ static int _dns_decode_opt(struct dns_context *context, dns_rr_type type, unsign
switch (opt_code) {
case DNS_OPT_T_ECS: {
struct dns_opt_ecs ecs;
ret = _dns_decode_opt_ecs(context, &ecs);
ret = _dns_decode_opt_ecs(context, &ecs, opt_len);
if (ret != 0) {
tlog(TLOG_ERROR, "decode ecs failed.");
return -1;
@@ -1895,7 +1896,7 @@ static int _dns_decode_opt(struct dns_context *context, dns_rr_type type, unsign
} break;
case DNS_OPT_T_COOKIE: {
struct dns_opt_cookie cookie;
ret = _dns_decode_opt_cookie(context, &cookie);
ret = _dns_decode_opt_cookie(context, &cookie, opt_len);
if (ret != 0) {
tlog(TLOG_ERROR, "decode cookie failed.");
return -1;
@@ -2254,6 +2255,16 @@ static int _dns_encode_qd(struct dns_context *context, struct dns_rrs *rrs)
return -1;
}
if (domain[0] == '-') {
/* for google and cloudflare */
unsigned char *ptr = context->ptr - 7;
memcpy(ptr, "\xC0\x12", 2);
ptr += 2;
_dns_write_short(&ptr, qtype);
_dns_write_short(&ptr, qclass);
context->ptr = ptr;
}
return 0;
}