#include <errno.h>
#include <unistd.h>
#include <string.h>
+#include <stdint.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <glib.h>
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+struct domain_hdr {
+ uint16_t id;
+ uint8_t rd:1;
+ uint8_t tc:1;
+ uint8_t aa:1;
+ uint8_t opcode:4;
+ uint8_t qr:1;
+ uint8_t rcode:4;
+ uint8_t z:3;
+ uint8_t ra:1;
+ uint16_t qdcount;
+ uint16_t ancount;
+ uint16_t nscount;
+ uint16_t arcount;
+} __attribute__ ((packed));
+#elif __BYTE_ORDER == __BIG_ENDIAN
+struct domain_hdr {
+ uint16_t id;
+ uint8_t qr:1;
+ uint8_t opcode:4;
+ uint8_t aa:1;
+ uint8_t tc:1;
+ uint8_t rd:1;
+ uint8_t ra:1;
+ uint8_t z:3;
+ uint8_t rcode:4;
+ uint16_t qdcount;
+ uint16_t ancount;
+ uint16_t nscount;
+ uint16_t arcount;
+} __attribute__ ((packed));
+#else
+#error "Unknown byte order"
+#endif
+
struct server_data {
char *interface;
+ char *domain;
char *server;
GIOChannel *channel;
guint watch;
struct request_data {
struct sockaddr_in sin;
socklen_t len;
- guint16 id;
+ guint16 srcid;
+ guint16 dstid;
+ guint16 altid;
+ guint timeout;
+ guint numserv;
+ guint numresp;
+ gpointer resp;
+ gsize resplen;
};
static GSList *server_list = NULL;
static GSList *request_list = NULL;
+static guint16 request_id = 0x0000;
static GIOChannel *listener_channel = NULL;
static guint listener_watch = 0;
GSList *list;
for (list = request_list; list; list = list->next) {
- struct request_data *data = list->data;
+ struct request_data *req = list->data;
- if (data->id == id)
- return data;
+ if (req->dstid == id || req->altid == id)
+ return req;
}
return NULL;
}
static struct server_data *find_server(const char *interface,
- const char *server)
+ const char *domain, const char *server)
{
GSList *list;
continue;
if (g_str_equal(data->interface, interface) == TRUE &&
- g_str_equal(data->server, server) == TRUE)
- return data;
+ g_str_equal(data->server, server) == TRUE) {
+ if (domain == NULL) {
+ if (data->domain == NULL)
+ return data;
+ continue;
+ }
+
+ if (g_str_equal(data->domain, domain) == TRUE)
+ return data;
+ }
}
return NULL;
static gboolean server_event(GIOChannel *channel, GIOCondition condition,
gpointer user_data)
{
+ struct server_data *data = user_data;
struct request_data *req;
unsigned char buf[768];
+ struct domain_hdr *hdr = (void *) &buf;
int sk, err, len;
+ if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
+ connman_error("Error with server channel");
+ data->watch = 0;
+ return FALSE;
+ }
+
sk = g_io_channel_unix_get_fd(channel);
len = recv(sk, buf, sizeof(buf), 0);
- if (len < 2)
+ if (len < 12)
return TRUE;
DBG("Received %d bytes (id 0x%04x)", len, buf[0] | buf[1] << 8);
if (req == NULL)
return TRUE;
+ DBG("id 0x%04x rcode %d", hdr->id, hdr->rcode);
+
+ buf[0] = req->srcid & 0xff;
+ buf[1] = req->srcid >> 8;
+
+ req->numresp++;
+
+ if (hdr->rcode == 0 || req->resp == NULL) {
+ g_free(req->resp);
+ req->resplen = 0;
+
+ req->resp = g_try_malloc(len);
+ if (req->resp == NULL)
+ return TRUE;
+
+ memcpy(req->resp, buf, len);
+ req->resplen = len;
+ }
+
+ if (hdr->rcode > 0 && req->numresp < req->numserv)
+ return TRUE;
+
+ if (req->timeout > 0)
+ g_source_remove(req->timeout);
+
request_list = g_slist_remove(request_list, req);
sk = g_io_channel_unix_get_fd(listener_channel);
- err = sendto(sk, buf, len, 0, (struct sockaddr *) &req->sin, req->len);
+ err = sendto(sk, req->resp, req->resplen, 0,
+ (struct sockaddr *) &req->sin, req->len);
+ g_free(req->resp);
g_free(req);
return TRUE;
}
static struct server_data *create_server(const char *interface,
- const char *server)
+ const char *domain, const char *server)
{
struct server_data *data;
struct sockaddr_in sin;
server_event, data);
data->interface = g_strdup(interface);
+ data->domain = g_strdup(domain);
data->server = g_strdup(server);
return data;
g_io_channel_unref(data->channel);
- g_free(data->interface);
g_free(data->server);
+ g_free(data->domain);
+ g_free(data->interface);
g_free(data);
}
DBG("interface %s server %s", interface, server);
- data = create_server(interface, server);
+ if (g_str_equal(server, "127.0.0.1") == TRUE)
+ return -ENODEV;
+
+ data = create_server(interface, domain, server);
if (data == NULL)
return -EIO;
DBG("interface %s server %s", interface, server);
- data = find_server(interface, server);
+ if (g_str_equal(server, "127.0.0.1") == TRUE)
+ return -ENODEV;
+
+ data = find_server(interface, domain, server);
if (data == NULL)
return 0;
.remove = dnsproxy_remove,
};
+static int parse_request(unsigned char *buf, int len,
+ char *name, unsigned int size)
+{
+ struct domain_hdr *hdr = (void *) buf;
+ uint16_t qdcount = ntohs(hdr->qdcount);
+ unsigned char *ptr;
+ char *last_label = NULL;
+ int label_count = 0;
+ unsigned int remain, used = 0;
+
+ if (len < 12)
+ return -EINVAL;
+
+ DBG("id 0x%04x qr %d opcode %d qdcount %d",
+ hdr->id, hdr->qr, hdr->opcode, qdcount);
+
+ if (hdr->qr != 0 || qdcount != 1)
+ return -EINVAL;
+
+ memset(name, 0, size);
+
+ ptr = buf + 12;
+ remain = len - 12;
+
+ while (remain > 0) {
+ uint8_t len = *ptr;
+
+ if (len == 0x00) {
+ if (label_count > 0)
+ last_label = (char *) (ptr + 1);
+ break;
+ }
+
+ label_count++;
+
+ if (used + len + 1 > size)
+ return -ENOBUFS;
+
+ strncat(name, (char *) (ptr + 1), len);
+ strcat(name, ".");
+
+ used += len + 1;
+
+ ptr += len + 1;
+ remain -= len + 1;
+ }
+
+ DBG("query %s (%d labels)", name, label_count);
+
+ return 0;
+}
+
+static void send_response(int sk, unsigned char *buf, int len,
+ const struct sockaddr *to, socklen_t tolen)
+{
+ struct domain_hdr *hdr = (void *) buf;
+ int err;
+
+ if (len < 12)
+ return;
+
+ DBG("id 0x%04x qr %d opcode %d", hdr->id, hdr->qr, hdr->opcode);
+
+ hdr->qr = 1;
+ hdr->rcode = 2;
+
+ hdr->ancount = 0;
+ hdr->nscount = 0;
+ hdr->arcount = 0;
+
+ err = sendto(sk, buf, len, 0, to, tolen);
+}
+
+static int append_query(unsigned char *buf, unsigned int size,
+ const char *query, const char *domain)
+{
+ unsigned char *ptr = buf;
+ char *offset;
+
+ DBG("query %s domain %s", query, domain);
+
+ offset = (char *) query;
+ while (offset != NULL) {
+ char *tmp;
+
+ tmp = strchr(offset, '.');
+ if (tmp == NULL) {
+ if (strlen(offset) == 0)
+ break;
+ *ptr = strlen(offset);
+ memcpy(ptr + 1, offset, strlen(offset));
+ ptr += strlen(offset) + 1;
+ break;
+ }
+
+ *ptr = tmp - offset;
+ memcpy(ptr + 1, offset, tmp - offset);
+ ptr += tmp - offset + 1;
+
+ offset = tmp + 1;
+ }
+
+ offset = (char *) domain;
+ while (offset != NULL) {
+ char *tmp;
+
+ tmp = strchr(offset, '.');
+ if (tmp == NULL) {
+ if (strlen(offset) == 0)
+ break;
+ *ptr = strlen(offset);
+ memcpy(ptr + 1, offset, strlen(offset));
+ ptr += strlen(offset) + 1;
+ break;
+ }
+
+ *ptr = tmp - offset;
+ memcpy(ptr + 1, offset, tmp - offset);
+ ptr += tmp - offset + 1;
+
+ offset = tmp + 1;
+ }
+
+ *ptr++ = 0x00;
+
+ return ptr - buf;
+}
+
+static gboolean request_timeout(gpointer user_data)
+{
+ struct request_data *req = user_data;
+
+ DBG("id 0x%04x", req->srcid);
+
+ request_list = g_slist_remove(request_list, req);
+
+ if (req->resplen > 0 && req->resp != NULL) {
+ int sk, err;
+
+ sk = g_io_channel_unix_get_fd(listener_channel);
+
+ err = sendto(sk, req->resp, req->resplen, 0,
+ (struct sockaddr *) &req->sin, req->len);
+ }
+
+ g_free(req->resp);
+ g_free(req);
+
+ return FALSE;
+}
+
static gboolean listener_event(GIOChannel *channel, GIOCondition condition,
gpointer user_data)
{
GSList *list;
unsigned char buf[768];
+ char query[512];
struct request_data *req;
struct sockaddr_in sin;
socklen_t size = sizeof(sin);
int sk, err, len;
+ if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
+ connman_error("Error with listener channel");
+ listener_watch = 0;
+ return FALSE;
+ }
+
sk = g_io_channel_unix_get_fd(channel);
memset(&sin, 0, sizeof(sin));
DBG("Received %d bytes (id 0x%04x)", len, buf[0] | buf[1] << 8);
- if (g_slist_length(server_list) == 0)
+ err = parse_request(buf, len, query, sizeof(query));
+ if (err < 0 || g_slist_length(server_list) == 0) {
+ send_response(sk, buf, len, (struct sockaddr *) &sin, size);
return TRUE;
+ }
- req = find_request(buf[0] | (buf[1] << 8));
- if (req == NULL) {
- req = g_try_new0(struct request_data, 1);
- if (req == NULL)
- return TRUE;
+ req = g_try_new0(struct request_data, 1);
+ if (req == NULL)
+ return TRUE;
- memcpy(&req->sin, &sin, sizeof(sin));
- req->len = size;
- req->id = buf[0] | (buf[1] << 8);
+ memcpy(&req->sin, &sin, sizeof(sin));
+ req->len = size;
- request_list = g_slist_append(request_list, req);
- } else {
- memcpy(&req->sin, &sin, sizeof(sin));
- req->len = size;
- }
+ request_id += 2;
+ if (request_id == 0x0000 || request_id == 0xffff)
+ request_id += 2;
+
+ req->srcid = buf[0] | (buf[1] << 8);
+ req->dstid = request_id;
+ req->altid = request_id + 1;
+
+ buf[0] = req->dstid & 0xff;
+ buf[1] = req->dstid >> 8;
+
+ request_list = g_slist_append(request_list, req);
+
+ req->numserv = 0;
+ req->timeout = g_timeout_add_seconds(5, request_timeout, req);
for (list = server_list; list; list = list->next) {
struct server_data *data = list->data;
+ DBG("server %s domain %s", data->server, data->domain);
+
sk = g_io_channel_unix_get_fd(data->channel);
err = send(sk, buf, len, 0);
+
+ req->numserv++;
+
+ if (data->domain != NULL) {
+ unsigned char alt[1024];
+ struct domain_hdr *hdr = (void *) &alt;
+ int altlen;
+
+ alt[0] = req->altid & 0xff;
+ alt[1] = req->altid >> 8;
+
+ memcpy(alt + 2, buf + 2, 10);
+ hdr->qdcount = htons(1);
+
+ altlen = append_query(alt + 12, sizeof(alt) - 12,
+ query, data->domain);
+ if (altlen < 0)
+ continue;
+
+ alt[altlen + 12] = 0x00;
+ alt[altlen + 13] = 0x01;
+ alt[altlen + 14] = 0x00;
+ alt[altlen + 15] = 0x01;
+
+ err = send(sk, alt, altlen + 12 + 4, 0);
+
+ req->numserv++;
+ }
}
return TRUE;
listener_watch = g_io_add_watch(listener_channel, G_IO_IN,
listener_event, NULL);
+ connman_resolver_append("lo", NULL, "127.0.0.1");
+
return 0;
}
DBG("");
+ connman_resolver_remove_all("lo");
+
if (listener_watch > 0)
g_source_remove(listener_watch);
for (list = request_list; list; list = list->next) {
- struct request_data *data = list->data;
+ struct request_data *req = list->data;
- DBG("Dropping request (id 0x%04x)", data->id);
+ DBG("Dropping request (id 0x%04x -> 0x%04x)",
+ req->srcid, req->dstid);
- g_free(data);
+ g_free(req->resp);
+ g_free(req);
list->data = NULL;
}
}
CONNMAN_PLUGIN_DEFINE(dnsproxy, "DNS proxy resolver plugin", VERSION,
- dnsproxy_init, dnsproxy_exit)
+ CONNMAN_PLUGIN_PRIORITY_DEFAULT, dnsproxy_init, dnsproxy_exit)