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Update code

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This commit is contained in:
Nick Peng
2018-05-17 00:03:00 +08:00
parent 924745da04
commit b7b49decc0
3 changed files with 120 additions and 248 deletions
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303
dns.c
View File

@@ -132,7 +132,7 @@ unsigned char *_dns_add_rrs_start(struct dns_packet *packet, int *maxlen)
return rrs->data;
}
int dns_rr_add_end(struct dns_packet *packet, int type, dns_type_t rrtype, int len)
int dns_rr_add_end(struct dns_packet *packet, int type, dns_type_t rtype, int len)
{
struct dns_rrs *rrs;
struct dns_rrs *rrs_next;
@@ -181,7 +181,7 @@ int dns_rr_add_end(struct dns_packet *packet, int type, dns_type_t rrtype, int l
rrs->next = DNS_RR_END; //*start;
*count += 1;
rrs->len = len;
rrs->type = rrtype;
rrs->type = rtype;
packet->len += len + sizeof(*rrs);
return 0;
}
@@ -293,20 +293,18 @@ int _dns_get_rr_head(struct dns_data_context *data_context, char *domain, int ma
return len;
}
int dns_add_CNAME(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, char *cname)
int dns_add_RAW(struct dns_packet *packet, dns_rr_type rrtype, dns_type_t rtype, char *domain, int ttl, void *raw, int raw_len)
{
int maxlen = 0;
int len = 0;
struct dns_data_context data_context;
int rr_len = 0;
rr_len = strnlen(cname, maxlen - 1) + 1;
unsigned char *data = _dns_add_rrs_start(packet, &maxlen);
if (data == NULL) {
return -1;
}
if (rr_len >= maxlen) {
if (raw_len >= maxlen) {
return -1;
}
@@ -314,180 +312,98 @@ int dns_add_CNAME(struct dns_packet *packet, dns_rr_type type, char *domain, int
data_context.ptr = data;
data_context.maxsize = maxlen;
len = _dns_add_rr_head(&data_context, domain, DNS_T_CNAME, DNS_C_IN, ttl, rr_len);
len = _dns_add_rr_head(&data_context, domain, rtype, DNS_C_IN, ttl, raw_len);
if (len < 0) {
return -1;
}
memcpy(data_context.ptr, cname, rr_len);
data_context.ptr += rr_len;
memcpy(data_context.ptr, raw, raw_len);
data_context.ptr += raw_len;
len = data_context.ptr - data_context.data;
return dns_rr_add_end(packet, type, DNS_T_CNAME, len);
return dns_rr_add_end(packet, rrtype, rtype, len);
}
int dns_get_RAW(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, void *raw, int raw_len)
{
int qtype = 0;
int qclass = 0;
int rr_len = 0;
int ret = 0;
struct dns_data_context data_context;
unsigned char *data = rrs->data;
data_context.data = data;
data_context.ptr = data;
data_context.maxsize = rrs->len;
ret = _dns_get_rr_head(&data_context, domain, maxsize, &qtype, &qclass, ttl, &rr_len);
if (ret < 0) {
return -1;
}
if (qtype != rrs->type || rr_len > raw_len) {
return -1;
}
memcpy(raw, data_context.ptr, rr_len);
data_context.ptr += rr_len;
return 0;
}
int dns_add_CNAME(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, char *cname)
{
int rr_len = strnlen(cname, DNS_MAX_CNAME_LEN) + 1;
return dns_add_RAW(packet, type, DNS_T_CNAME, domain, ttl, cname, rr_len);
}
int dns_get_CNAME(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, char *cname, int cname_size)
{
int qtype = 0;
int qclass = 0;
int rr_len = 0;
int ret = 0;
struct dns_data_context data_context;
unsigned char *data = rrs->data;
if (rrs->type != DNS_T_CNAME) {
return -1;
}
data_context.data = data;
data_context.ptr = data;
data_context.maxsize = rrs->len;
ret = _dns_get_rr_head(&data_context, domain, maxsize, &qtype, &qclass, ttl, &rr_len);
if (ret < 0) {
return -1;
}
if (qtype != DNS_T_CNAME || rr_len > cname_size) {
return -1;
}
memcpy(cname, data_context.ptr, rr_len);
return 0;
return dns_get_RAW(rrs, domain, maxsize, ttl, cname, cname_size);
}
int dns_add_A(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, unsigned char addr[4])
int dns_add_A(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, unsigned char addr[DNS_RR_A_LEN])
{
int maxlen = 0;
int len = 0;
struct dns_data_context data_context;
return dns_add_RAW(packet, type, DNS_T_A, domain, ttl, addr, DNS_RR_A_LEN);
}
unsigned char *data = _dns_add_rrs_start(packet, &maxlen);
if (data == NULL) {
return -1;
}
data_context.data = data;
data_context.ptr = data;
data_context.maxsize = maxlen;
len = _dns_add_rr_head(&data_context, domain, DNS_T_A, DNS_C_IN, ttl, DNS_RR_A_LEN);
if (len < 0) {
return -1;
}
memcpy(data_context.ptr, addr, DNS_RR_A_LEN);
data_context.ptr += DNS_RR_A_LEN;
len = data_context.ptr - data_context.data;
return dns_rr_add_end(packet, type, DNS_T_A, len);
int dns_get_A(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, unsigned char addr[DNS_RR_A_LEN])
{
return dns_get_RAW(rrs, domain, maxsize, ttl, addr, DNS_RR_A_LEN);
}
int dns_add_PTR(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, char *cname)
{
return dns_add_CNAME(packet, type, domain, ttl, cname);
int rr_len = strnlen(cname, DNS_MAX_CNAME_LEN) + 1;
return dns_add_RAW(packet, type, DNS_T_PTR, domain, ttl, cname, rr_len);
}
int dns_get_PTR(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, char *cname, int cname_size)
{
return dns_get_CNAME(rrs, domain, maxsize, ttl, cname, cname_size);
return dns_get_RAW(rrs, domain, maxsize, ttl, cname, cname_size);
}
int dns_get_A(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, unsigned char addr[4])
int dns_add_NS(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, char *cname)
{
int qtype = 0;
int qclass = 0;
int rr_len = 0;
int ret = 0;
struct dns_data_context data_context;
unsigned char *data = rrs->data;
if (rrs->type != DNS_T_A) {
return -1;
}
data_context.data = data;
data_context.ptr = data;
data_context.maxsize = rrs->len;
ret = _dns_get_rr_head(&data_context, domain, maxsize, &qtype, &qclass, ttl, &rr_len);
if (ret < 0) {
return -1;
}
if (qtype != DNS_T_A || rr_len != DNS_RR_A_LEN) {
return -1;
}
memcpy(addr, data_context.ptr, DNS_RR_A_LEN);
return 0;
int rr_len = strnlen(cname, DNS_MAX_CNAME_LEN) + 1;
return dns_add_RAW(packet, type, DNS_T_NS, domain, ttl, cname, rr_len);
}
int dns_add_AAAA(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, unsigned char addr[16])
int dns_get_NS(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, char *cname, int cname_size)
{
int maxlen = 0;
int len = 0;
struct dns_data_context data_context;
unsigned char *data = _dns_add_rrs_start(packet, &maxlen);
if (data == NULL) {
return -1;
}
data_context.data = data;
data_context.ptr = data;
data_context.maxsize = maxlen;
len = _dns_add_rr_head(&data_context, domain, DNS_T_AAAA, DNS_C_IN, ttl, DNS_RR_AAAA_LEN);
if (len < 0) {
return -1;
}
memcpy(data_context.ptr, addr, DNS_RR_AAAA_LEN);
data_context.ptr += DNS_RR_AAAA_LEN;
len = data_context.ptr - data_context.data;
return dns_rr_add_end(packet, type, DNS_T_AAAA, len);
return dns_get_RAW(rrs, domain, maxsize, ttl, cname, cname_size);
}
int dns_get_AAAA(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, unsigned char addr[16])
int dns_add_AAAA(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, unsigned char addr[DNS_RR_AAAA_LEN])
{
int qtype = 0;
int qclass = 0;
int rr_len = 0;
int ret = 0;
struct dns_data_context data_context;
return dns_add_RAW(packet, type, DNS_T_AAAA, domain, ttl, addr, DNS_RR_AAAA_LEN);
}
if (rrs->type != DNS_T_AAAA) {
return -1;
}
unsigned char *data = rrs->data;
if (rrs->type != DNS_T_AAAA) {
return -1;
}
data_context.data = data;
data_context.ptr = data;
data_context.maxsize = rrs->len;
ret = _dns_get_rr_head(&data_context, domain, maxsize, &qtype, &qclass, ttl, &rr_len);
if (ret < 0) {
return -1;
}
if (qtype != DNS_T_AAAA || rr_len != DNS_RR_AAAA_LEN) {
return -1;
}
memcpy(addr, data_context.ptr, DNS_RR_AAAA_LEN);
return 0;
int dns_get_AAAA(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, unsigned char addr[DNS_RR_AAAA_LEN])
{
return dns_get_RAW(rrs, domain, maxsize, ttl, addr, DNS_RR_AAAA_LEN);
}
/*
@@ -785,10 +701,11 @@ int _dns_encode_CNAME(struct dns_context *context, struct dns_rrs *rrs)
return -1;
}
ret = _dns_encode_domain(context, (char *)rrs->data);
ret = _dns_encode_domain(context, (char *)data_context.ptr);
if (ret < 0) {
return -1;
}
data_context.ptr += strnlen((char*)(data_context.ptr), DNS_MAX_CNAME_LEN) + 1;
return 0;
}
@@ -838,6 +755,7 @@ int _dns_encode_A(struct dns_context *context, struct dns_rrs *rrs)
memcpy(context->ptr, data_context.ptr, DNS_RR_A_LEN);
context->ptr += DNS_RR_A_LEN;
data_context.ptr += DNS_RR_A_LEN;
return 0;
}
@@ -852,42 +770,7 @@ int _dns_decode_PTR(struct dns_context *context, char *name, int name_size)
int _dns_encode_PTR(struct dns_context *context, struct dns_rrs *rrs)
{
int ret;
int qtype = 0;
int qclass = 0;
int ttl = 0;
char domain[DNS_MAX_CNAME_LEN];
int rr_len;
struct dns_data_context data_context;
data_context.data = rrs->data;
data_context.ptr = rrs->data;
data_context.maxsize = rrs->len;
ret = _dns_get_rr_head(&data_context, domain, DNS_MAX_CNAME_LEN, &qtype, &qclass, &ttl, &rr_len);
if (ret < 0) {
return -1;
}
if (rr_len >= data_context.maxsize) {
return -1;
}
ret = _dns_encode_rr_head(context, domain, qtype, qclass, ttl, rr_len);
if (ret < 0) {
return -1;
}
if (_dns_left_len(context) < rr_len) {
return -1;
}
ret = _dns_encode_domain(context, (char *)data_context.ptr);
if (ret < 0) {
return -1;
}
return 0;
return _dns_encode_CNAME(context, rrs);
}
int _dns_decode_AAAA(struct dns_context *context, unsigned char addr[DNS_RR_AAAA_LEN])
@@ -933,8 +816,9 @@ int _dns_encode_AAAA(struct dns_context *context, struct dns_rrs *rrs)
return -1;
}
memcpy(context->ptr, context->ptr, DNS_RR_AAAA_LEN);
memcpy(context->ptr, data_context.ptr, DNS_RR_AAAA_LEN);
context->ptr += DNS_RR_AAAA_LEN;
data_context.ptr += DNS_RR_AAAA_LEN;
return 0;
}
@@ -952,40 +836,7 @@ int _dns_decode_NS(struct dns_context *context, unsigned char addr[4])
int _dns_encode_NS(struct dns_context *context, struct dns_rrs *rrs)
{
int ret;
int qtype = 0;
int qclass = 0;
int ttl = 0;
char domain[DNS_MAX_CNAME_LEN];
int rr_len;
struct dns_data_context data_context;
data_context.data = rrs->data;
data_context.ptr = rrs->data;
data_context.maxsize = rrs->len;
ret = _dns_get_rr_head(&data_context, domain, DNS_MAX_CNAME_LEN, &qtype, &qclass, &ttl, &rr_len);
if (ret < 0) {
return -1;
}
if (rr_len != DNS_RR_A_LEN) {
return -1;
}
ret = _dns_encode_rr_head(context, domain, qtype, qclass, ttl, DNS_RR_A_LEN);
if (ret < 0) {
return -1;
}
if (_dns_left_len(context) < DNS_RR_A_LEN) {
return -1;
}
memcpy(context->ptr, rrs->data, DNS_RR_A_LEN);
context->ptr += DNS_RR_A_LEN;
return 0;
return _dns_encode_CNAME(context, rrs);
}
int _dns_decode_qd(struct dns_context *context)
@@ -1051,6 +902,18 @@ int _dns_decode_an(struct dns_context *context, dns_rr_type type)
return -1;
}
} break;
case DNS_T_NS: {
char ns[DNS_MAX_CNAME_LEN];
ret = _dns_decode_CNAME(context, ns, DNS_MAX_CNAME_LEN);
if (ret < 0) {
return -1;
}
ret = dns_add_NS(packet, type, domain, ttl, ns);
if (ret < 0) {
return -1;
}
} break;
case DNS_T_PTR: {
char name[DNS_MAX_CNAME_LEN];
ret = _dns_decode_PTR(context, name, DNS_MAX_CNAME_LEN);

16
dns.h
View File

@@ -8,7 +8,9 @@
#define DNS_RR_A_LEN 4
#define DNS_RR_AAAA_LEN 16
#define DNS_MAX_CNAME_LEN 128
#define DNS_MAX_CNAME_LEN 256
#define DNS_IN_PACKSIZE 512
#define DNS_PACKSIZE (512 * 2)
typedef enum dns_rr_type {
DNS_RRS_QD = 0,
@@ -125,18 +127,22 @@ int dns_add_CNAME(struct dns_packet *packet, dns_rr_type type, char *domain, int
int dns_get_CNAME(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, char *cname, int cname_size);
int dns_add_A(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, unsigned char addr[4]);
int dns_add_A(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, unsigned char addr[DNS_RR_A_LEN]);
int dns_get_A(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, unsigned char addr[4]);
int dns_get_A(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, unsigned char addr[DNS_RR_A_LEN]);
int dns_add_PTR(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, char *cname);
int dns_get_PTR(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, char *cname, int cname_size);
int dns_add_AAAA(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, unsigned char addr[16]);
int dns_add_AAAA(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, unsigned char addr[DNS_RR_AAAA_LEN]);
int dns_get_AAAA(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, unsigned char addr[16]);
int dns_get_AAAA(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, unsigned char addr[DNS_RR_AAAA_LEN]);
/*
* Packet operation
*/
int dns_decode(struct dns_packet *packet, int maxsize, unsigned char *data, int size);
int dns_encode(unsigned char *data, int size, struct dns_packet *packet);

49
dns_server.c
View File

@@ -18,6 +18,7 @@
#include "dns_server.h"
#include "dns.h"
#include "list.h"
#include "hashtable.h"
#include <arpa/inet.h>
#include <errno.h>
@@ -39,8 +40,6 @@
#define DNS_MAX_EVENTS 256
#define DNS_INPACKET_SIZE 512
struct dns_server {
int run;
int epoll_fd;
@@ -51,6 +50,12 @@ struct dns_server {
DECLARE_HASHTABLE(hostmap, 6);
};
struct dns_request {
struct hlist_node map;
char host[DNS_MAX_CNAME_LEN];
};
static struct dns_server server;
static void tv_sub(struct timeval *out, struct timeval *in)
@@ -64,8 +69,8 @@ static void tv_sub(struct timeval *out, struct timeval *in)
void _dns_server_period_run()
{
unsigned char packet_data[DNS_INPACKET_SIZE];
unsigned char data[DNS_INPACKET_SIZE];
unsigned char packet_data[DNS_PACKSIZE];
unsigned char data[DNS_IN_PACKSIZE];
struct dns_packet *packet = (struct dns_packet *)packet_data;
@@ -81,9 +86,9 @@ void _dns_server_period_run()
struct sockaddr_in to;
socklen_t to_len = sizeof(to);
dns_packet_init(packet, DNS_INPACKET_SIZE, &head);
dns_add_domain(packet, "www.huawei.com", 1, 1);
len = dns_encode(data, DNS_INPACKET_SIZE, packet);
dns_packet_init(packet, DNS_PACKSIZE, &head);
dns_add_domain(packet, "www.huawei.com", DNS_T_A, 1);
len = dns_encode(data, DNS_IN_PACKSIZE, packet);
memset(&to, 0, sizeof(to));
to.sin_addr.s_addr = inet_addr("192.168.1.1");
@@ -98,10 +103,10 @@ void _dns_server_period_run()
static int _dns_server_process(struct timeval *now)
{
int len;
unsigned char inpacket[DNS_INPACKET_SIZE];
unsigned char rsppacket[DNS_INPACKET_SIZE];
unsigned char aswpacket[DNS_INPACKET_SIZE];
unsigned char outpacket[DNS_INPACKET_SIZE];
unsigned char inpacket[DNS_IN_PACKSIZE];
unsigned char rsppacket[DNS_PACKSIZE];
unsigned char aswpacket[DNS_PACKSIZE];
unsigned char outpacket[DNS_IN_PACKSIZE];
struct dns_packet *packet = (struct dns_packet *)rsppacket;
struct dns_packet *anspacket = (struct dns_packet *)aswpacket;
@@ -117,7 +122,7 @@ static int _dns_server_process(struct timeval *now)
}
data_len = len;
len = dns_decode(packet, DNS_INPACKET_SIZE, inpacket, len);
len = dns_decode(packet, DNS_PACKSIZE, inpacket, len);
if (len) {
printf("decode failed.\n");
return 0;
@@ -137,12 +142,12 @@ static int _dns_server_process(struct timeval *now)
memset(&head, 0, sizeof(head));
head.rcode = 0;
head.qr = 1;
head.rd = 1;
head.ra = 0;
head.rd = packet->head.rd;
head.ra = packet->head.ra;
head.id = packet->head.id;
int n = 0;
dns_packet_init(anspacket, DNS_INPACKET_SIZE, &head);
dns_packet_init(anspacket, DNS_PACKSIZE, &head);
printf("qdcount = %d, ancount = %d, nscount = %d, nrcount = %d, len = %d\n", packet->head.qdcount, packet->head.ancount, packet->head.nscount,
packet->head.nrcount, data_len);
@@ -155,18 +160,16 @@ static int _dns_server_process(struct timeval *now)
case DNS_T_A: {
unsigned char addr[4];
addr[0] = 192;
addr[1] = 188;
addr[1] = 148;
addr[2] = 9;
addr[3] = 8;
addr[3] = 3;
dns_add_A(anspacket, DNS_RRS_AN, name, 60 * 60, addr);
n++;
} break;
case DNS_T_AAAA: {
unsigned char addr[16];
addr[0] = 192;
addr[1] = 188;
addr[2] = 9;
addr[3] = 8;
memset(addr, 0, 16);
addr[0] = 1;
dns_add_AAAA(anspacket, DNS_RRS_AN, name, 60 * 60, addr);
n++;
} break;
@@ -180,8 +183,8 @@ static int _dns_server_process(struct timeval *now)
}
if (n > 0 && packet->head.qr == 0) {
dns_add_CNAME(anspacket, DNS_RRS_AN, name, 60 * 60, name);
len = dns_encode(outpacket, DNS_INPACKET_SIZE, anspacket);
dns_add_domain(anspacket, name, qtype, qclass);
len = dns_encode(outpacket, DNS_IN_PACKSIZE, anspacket);
sendto(server.fd, outpacket, len, 0, (struct sockaddr *)&from, from_len);
}