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dns_server: support TCP keepalive timeout EDNS

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This commit is contained in:
Nick Peng
2023-11-16 23:16:37 +08:00
parent a482ceeb5a
commit 9a83df46e0
7 changed files with 161 additions and 70 deletions
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45
src/dns.c
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@@ -738,14 +738,14 @@ static int _dns_add_opt_RAW(struct dns_packet *packet, dns_opt_code_t opt_rrtype
struct dns_opt *opt = (struct dns_opt *)opt_data;
int len = 0;
opt->code = DNS_OPT_T_TCP_KEEPALIVE;
opt->code = opt_rrtype;
opt->length = sizeof(unsigned short);
memcpy(opt->data, raw, raw_len);
len += raw_len;
len += sizeof(*opt);
return _dns_add_RAW(packet, DNS_RRS_OPT, (dns_type_t)DNS_OPT_T_TCP_KEEPALIVE, "", 0, opt_data, len);
return _dns_add_RAW(packet, DNS_RRS_OPT, (dns_type_t)opt_rrtype, "", 0, opt_data, len);
}
static int _dns_get_opt_RAW(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, struct dns_opt *dns_opt,
@@ -1030,7 +1030,7 @@ int dns_add_OPT_ECS(struct dns_packet *packet, struct dns_opt_ecs *ecs)
return _dns_add_RAW(packet, DNS_RRS_OPT, (dns_type_t)DNS_OPT_T_ECS, "", 0, opt_data, len);
}
int dns_get_OPT_ECS(struct dns_rrs *rrs, unsigned short *opt_code, unsigned short *opt_len, struct dns_opt_ecs *ecs)
int dns_get_OPT_ECS(struct dns_rrs *rrs, struct dns_opt_ecs *ecs)
{
unsigned char opt_data[DNS_MAX_OPT_LEN];
char domain[DNS_MAX_CNAME_LEN] = {0};
@@ -1067,16 +1067,16 @@ int dns_add_OPT_TCP_KEEPALIVE(struct dns_packet *packet, unsigned short timeout)
return _dns_add_opt_RAW(packet, DNS_OPT_T_TCP_KEEPALIVE, &timeout_net, data_len);
}
int dns_get_OPT_TCP_KEEPALIVE(struct dns_rrs *rrs, unsigned short *opt_code, unsigned short *opt_len,
unsigned short *timeout)
int dns_get_OPT_TCP_KEEPALIVE(struct dns_rrs *rrs, unsigned short *timeout)
{
unsigned char opt_data[DNS_MAX_OPT_LEN];
char domain[DNS_MAX_CNAME_LEN] = {0};
struct dns_opt *opt = (struct dns_opt *)opt_data;
int len = DNS_MAX_OPT_LEN;
int ttl = 0;
unsigned char *data = NULL;
if (_dns_get_opt_RAW(rrs, NULL, 0, &ttl, opt, &len) != 0) {
if (_dns_get_opt_RAW(rrs, domain, DNS_MAX_CNAME_LEN, &ttl, opt, &len) != 0) {
return -1;
}
@@ -1757,6 +1757,23 @@ static int _dns_decode_opt_cookie(struct dns_context *context, struct dns_opt_co
return 0;
}
static int _dns_decode_opt_tcp_keepalive(struct dns_context *context, unsigned short *timeout, int opt_len)
{
if (opt_len == 0) {
*timeout = 0;
return 0;
}
if (opt_len < (int)sizeof(unsigned short)) {
return -1;
}
*timeout = _dns_read_short(&context->ptr);
tlog(TLOG_DEBUG, "OPT TCP KEEPALIVE %u", *timeout);
return 0;
}
static int _dns_encode_OPT(struct dns_context *context, struct dns_rrs *rrs)
{
int ret = 0;
@@ -1875,7 +1892,7 @@ static int _dns_decode_opt(struct dns_context *context, dns_rr_type type, unsign
unsigned short opt_code = 0;
unsigned short opt_len = 0;
unsigned short errcode = (ttl >> 16) & 0xFFFF;
unsigned short ever = (ttl)&0xFFFF;
unsigned short ever = (ttl) & 0xFFFF;
unsigned char *start = context->ptr;
struct dns_packet *packet = context->packet;
int ret = 0;
@@ -1960,6 +1977,20 @@ static int _dns_decode_opt(struct dns_context *context, dns_rr_type type, unsign
return -1;
}
} break;
case DNS_OPT_T_TCP_KEEPALIVE: {
unsigned short timeout = 0;
ret = _dns_decode_opt_tcp_keepalive(context, &timeout, opt_len);
if (ret != 0) {
tlog(TLOG_ERROR, "decode tcp keepalive failed.");
return -1;
}
ret = dns_add_OPT_TCP_KEEPALIVE(packet, timeout);
if (ret != 0) {
tlog(TLOG_ERROR, "add tcp keepalive failed.");
return -1;
}
} break;
case DNS_OPT_T_PADDING:
context->ptr += opt_len;
break;