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dns_server: improve code readability
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@pymumu
pymumu committed Jun 2, 2023
1 parent f621b42 commit f5c8d3c
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Showing 3 changed files with 71 additions and 33 deletions.
22 changes: 10 additions & 12 deletions src/dns_client.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2247,7 +2247,6 @@ static int _dns_client_process_udp_proxy(struct dns_server_info *server_info, st
return 0;
}


/* update recv time */
time(&server_info->last_recv);

Expand Down Expand Up @@ -3892,31 +3891,30 @@ static void _dns_client_check_servers(void)
pthread_mutex_unlock(&client.server_list_lock);
}

static int _dns_client_pending_server_resolve(const char *domain, dns_rtcode_t rtcode, dns_type_t addr_type, char *ip,
unsigned int ping_time, void *user_ptr)
static int _dns_client_pending_server_resolve(const struct dns_result *result, void *user_ptr)
{
struct dns_server_pending *pending = user_ptr;
int ret = 0;

if (rtcode == DNS_RC_NXDOMAIN) {
if (result->rtcode == DNS_RC_NXDOMAIN) {
pending->has_soa = 1;
}

if (addr_type == DNS_T_A) {
if (result->addr_type == DNS_T_A) {
pending->ping_time_v4 = -1;
if (rtcode == DNS_RC_NOERROR) {
if (result->rtcode == DNS_RC_NOERROR) {
pending->has_v4 = 1;
pending->ping_time_v4 = ping_time;
pending->ping_time_v4 = result->ping_time;
pending->has_soa = 0;
safe_strncpy(pending->ipv4, ip, DNS_HOSTNAME_LEN);
safe_strncpy(pending->ipv4, result->ip, DNS_HOSTNAME_LEN);
}
} else if (addr_type == DNS_T_AAAA) {
} else if (result->addr_type == DNS_T_AAAA) {
pending->ping_time_v6 = -1;
if (rtcode == DNS_RC_NOERROR) {
if (result->rtcode == DNS_RC_NOERROR) {
pending->has_v6 = 1;
pending->ping_time_v6 = ping_time;
pending->ping_time_v6 = result->ping_time;
pending->has_soa = 0;
safe_strncpy(pending->ipv6, ip, DNS_HOSTNAME_LEN);
safe_strncpy(pending->ipv6, result->ip, DNS_HOSTNAME_LEN);
}
} else {
ret = -1;
Expand Down
67 changes: 48 additions & 19 deletions src/dns_server.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -128,6 +128,7 @@ struct dns_server_post_context {
struct dns_request *request;
struct dns_packet *packet;
int ip_num;
const unsigned char *ip_addr[MAX_IP_NUM];
dns_type_t qtype;
int do_cache;
int do_reply;
Expand Down Expand Up @@ -284,7 +285,7 @@ struct dns_request {
int request_wait;
int prefetch;
int prefetch_expired_domain;

int dualstack_selection;
int dualstack_selection_force_soa;
int dualstack_selection_query;
Expand Down Expand Up @@ -894,6 +895,7 @@ static int _dns_rrs_add_all_best_ip(struct dns_server_post_context *context)
}
}

context->ip_addr[context->ip_num] = addr_map->ip_addr;
context->ip_num++;
if (addr_map->addr_type == DNS_T_A) {
ret |= dns_add_A(context->packet, DNS_RRS_AN, domain, request->ip_ttl, addr_map->ip_addr);
Expand Down Expand Up @@ -947,6 +949,7 @@ static int _dns_add_rrs(struct dns_server_post_context *context)

/* add A record */
if (request->has_ip && context->do_force_soa == 0) {
context->ip_addr[0] = request->ip_addr;
context->ip_num++;
if (context->qtype == DNS_T_A) {
ret |= dns_add_A(context->packet, DNS_RRS_AN, domain, request->ip_ttl, request->ip_addr);
Expand Down Expand Up @@ -1496,11 +1499,21 @@ static int _dns_result_callback_nxdomain(struct dns_request *request)
return 0;
}

return request->result_callback(request->domain, request->rcode, request->qtype, ip, ping_time, request->user_ptr);
struct dns_result result;
result.domain = request->domain;
result.rtcode = request->rcode;
result.addr_type = request->qtype;
result.ip = ip;
result.ping_time = ping_time;
memset(&result.ip_addr, 0, sizeof(result.ip_addr));
result.ip_num = 0;

return request->result_callback(&result, request->user_ptr);
}

static int _dns_result_callback(struct dns_server_post_context *context)
{
struct dns_result result;
char ip[DNS_MAX_CNAME_LEN];
unsigned int ping_time = -1;
struct dns_request *request = context->request;
Expand All @@ -1522,20 +1535,29 @@ static int _dns_result_callback(struct dns_server_post_context *context)
}

ip[0] = 0;
memset(&result, 0, sizeof(result));
ping_time = request->ping_time;
if (request->qtype == DNS_T_A) {
result.domain = request->domain;
result.rtcode = request->rcode;
result.addr_type = request->qtype;
result.ip = ip;
result.ping_time = ping_time;
result.ip_num = 0;
for (int i = 0; i < context->ip_num && i < MAX_IP_NUM; i++) {
result.ip_addr[i] = context->ip_addr[i];
result.ip_num++;
}

if (request->qtype == DNS_T_A) {
sprintf(ip, "%d.%d.%d.%d", request->ip_addr[0], request->ip_addr[1], request->ip_addr[2], request->ip_addr[3]);
return request->result_callback(request->domain, request->rcode, request->qtype, ip, ping_time,
request->user_ptr);
return request->result_callback(&result, request->user_ptr);
} else if (request->qtype == DNS_T_AAAA) {
sprintf(ip, "%.2x%.2x:%.2x%.2x:%.2x%.2x:%.2x%.2x:%.2x%.2x:%.2x%.2x:%.2x%.2x:%.2x%.2x", request->ip_addr[0],
request->ip_addr[1], request->ip_addr[2], request->ip_addr[3], request->ip_addr[4], request->ip_addr[5],
request->ip_addr[6], request->ip_addr[7], request->ip_addr[8], request->ip_addr[9],
request->ip_addr[10], request->ip_addr[11], request->ip_addr[12], request->ip_addr[13],
request->ip_addr[14], request->ip_addr[15]);
return request->result_callback(request->domain, request->rcode, request->qtype, ip, ping_time,
request->user_ptr);
return request->result_callback(&result, request->user_ptr);
}

_dns_result_callback_nxdomain(request);
Expand Down Expand Up @@ -2154,7 +2176,7 @@ static int _dns_server_request_complete(struct dns_request *request)
}

static int _dns_ip_address_check_add(struct dns_request *request, char *cname, unsigned char *addr,
dns_type_t addr_type, int ping_time)
dns_type_t addr_type, int ping_time, struct dns_ip_address **out_addr_map)
{
uint32_t key = 0;
struct dns_ip_address *addr_map = NULL;
Expand Down Expand Up @@ -2213,6 +2235,10 @@ static int _dns_ip_address_check_add(struct dns_request *request, char *cname, u
hash_add(request->ip_map, &addr_map->node, key);
pthread_mutex_unlock(&request->ip_map_lock);

if (out_addr_map != NULL) {
*out_addr_map = addr_map;
}

return 0;
}

Expand Down Expand Up @@ -2879,7 +2905,7 @@ static int _dns_server_process_answer_A(struct dns_rrs *rrs, struct dns_request
}

/* add this ip to request */
if (_dns_ip_address_check_add(request, cname, addr, DNS_T_A, 0) != 0) {
if (_dns_ip_address_check_add(request, cname, addr, DNS_T_A, 0, NULL) != 0) {
_dns_server_request_release(request);
return -1;
}
Expand Down Expand Up @@ -2956,7 +2982,7 @@ static int _dns_server_process_answer_AAAA(struct dns_rrs *rrs, struct dns_reque
}

/* add this ip to request */
if (_dns_ip_address_check_add(request, cname, addr, DNS_T_AAAA, 0) != 0) {
if (_dns_ip_address_check_add(request, cname, addr, DNS_T_AAAA, 0, NULL) != 0) {
_dns_server_request_release(request);
return -1;
}
Expand Down Expand Up @@ -3233,6 +3259,7 @@ static int _dns_server_get_answer(struct dns_server_post_context *context)
case DNS_T_A: {
unsigned char addr[4];
char name[DNS_MAX_CNAME_LEN] = {0};
struct dns_ip_address *addr_map = NULL;

if (request->qtype != DNS_T_A) {
continue;
Expand All @@ -3247,10 +3274,11 @@ static int _dns_server_get_answer(struct dns_server_post_context *context)
}

if (context->no_check_add_ip == 0 &&
_dns_ip_address_check_add(request, name, addr, DNS_T_A, request->ping_time) != 0) {
_dns_ip_address_check_add(request, name, addr, DNS_T_A, request->ping_time, &addr_map) != 0) {
continue;
}

context->ip_addr[context->ip_num] = addr_map->ip_addr;
context->ip_num++;
if (request->has_ip == 1) {
continue;
Expand All @@ -3265,6 +3293,7 @@ static int _dns_server_get_answer(struct dns_server_post_context *context)
case DNS_T_AAAA: {
unsigned char addr[16];
char name[DNS_MAX_CNAME_LEN] = {0};
struct dns_ip_address *addr_map = NULL;

if (request->qtype != DNS_T_AAAA) {
/* ignore non-matched query type */
Expand All @@ -3278,10 +3307,11 @@ static int _dns_server_get_answer(struct dns_server_post_context *context)
}

if (context->no_check_add_ip == 0 &&
_dns_ip_address_check_add(request, name, addr, DNS_T_AAAA, request->ping_time) != 0) {
_dns_ip_address_check_add(request, name, addr, DNS_T_AAAA, request->ping_time, &addr_map) != 0) {
continue;
}

context->ip_addr[context->ip_num] = addr_map->ip_addr;
context->ip_num++;
if (request->has_ip == 1) {
continue;
Expand Down Expand Up @@ -3416,21 +3446,20 @@ static void _dns_server_query_end(struct dns_request *request)
_dns_server_request_release(request);
}

static int dns_server_dualstack_callback(const char *domain, dns_rtcode_t rtcode, dns_type_t addr_type, char *ip,
unsigned int ping_time, void *user_ptr)
static int dns_server_dualstack_callback(const struct dns_result *result, void *user_ptr)
{
struct dns_request *request = (struct dns_request *)user_ptr;
tlog(TLOG_DEBUG, "dualstack result: domain: %s, ip: %s, type: %d, ping: %d, rcode: %d", domain, ip, addr_type,
ping_time, rtcode);
tlog(TLOG_DEBUG, "dualstack result: domain: %s, ip: %s, type: %d, ping: %d, rcode: %d", result->domain, result->ip,
result->addr_type, result->ping_time, result->rtcode);
if (request == NULL) {
return -1;
}

if (rtcode == DNS_RC_NOERROR && ip[0] != 0) {
if (result->rtcode == DNS_RC_NOERROR && result->ip[0] != 0) {
request->dualstack_selection_has_ip = 1;
}

request->dualstack_selection_ping_time = ping_time;
request->dualstack_selection_ping_time = result->ping_time;

_dns_server_query_end(request);

Expand Down Expand Up @@ -6650,7 +6679,7 @@ static int _dns_create_socket(const char *host_ip, int type)
{
int fd = -1;
struct addrinfo *gai = NULL;
char port_str[8];
char port_str[16];
char ip[MAX_IP_LEN];
char host_ip_device[MAX_IP_LEN * 2];
int port = 0;
Expand Down
15 changes: 13 additions & 2 deletions src/dns_server.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -49,9 +49,20 @@ void dns_server_stop(void);

void dns_server_exit(void);

#define MAX_IP_NUM 16

struct dns_result {
const char *domain;
dns_rtcode_t rtcode;
dns_type_t addr_type;
const char *ip;
const unsigned char *ip_addr[MAX_IP_NUM];
int ip_num;
unsigned int ping_time;
};

/* query result notify function */
typedef int (*dns_result_callback)(const char *domain, dns_rtcode_t rtcode, dns_type_t addr_type, char *ip,
unsigned int ping_time, void *user_ptr);
typedef int (*dns_result_callback)(const struct dns_result *result, void *user_ptr);

/* query domain */
int dns_server_query(const char *domain, int qtype, struct dns_server_query_option *server_query_option,
Expand Down

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