/**
* lwip MDNS resolver file.
*
* Created on: Jul 29, 2010
* Author: Daniel Toma
*
* ported from uIP resolv.c Copyright (c) 2002-2003, Adam Dunkels.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* This file implements a MDNS host name and PUCK service registration.
*-----------------------------------------------------------------------------
* Includes
*----------------------------------------------------------------------------*/
#include "lwip/opt.h"
#ifdef LWIP_MDNS /* don't build if not configured for use in lwipopts.h */
#include "lwip/mdns.h"
#include "lwip/udp.h"
#include "lwip/mem.h"
#include "lwip/igmp.h"
#include "osapi.h"
#include "os_type.h"
#include "user_interface.h"
#include "c_string.h"
#include "nodemcu_mdns.h"
#if 0
#define MDNS_DBG(...) os_printf(...)
#else
#define MDNS_DBG(...) do {} while (0)
#endif
#define min(a,b) ((a) < (b) ? (a) : (b))
#define MDNS_NAME_LENGTH 68 //68
#define DNS_RRTYPE_NSEC 47
static const char* service_name_with_suffix = NULL;
#define DNS_SD_SERVICE "_services._dns-sd._udp.local"
#define PUCK_SERVICE_LENGTH 30
#define PUCK_DATASHEET_SIZE 96
#ifdef MEMLEAK_DEBUG
static const char mem_debug_file[] ICACHE_RODATA_ATTR = __FILE__;
#endif
/** DNS server IP address */
#ifndef DNS_MULTICAST_ADDRESS
#define DNS_MULTICAST_ADDRESS ipaddr_addr("224.0.0.251") /* resolver1.opendns.com */
#endif
/** DNS server IP address */
#ifndef MDNS_LOCAL
#define MDNS_LOCAL "local" /* resolver1.opendns.com */
#endif
/** DNS server port address */
#ifndef DNS_MDNS_PORT
#define DNS_MDNS_PORT 5353
#endif
/** DNS maximum number of retries when asking for a name, before "timeout". */
#ifndef DNS_MAX_RETRIES
#define DNS_MAX_RETRIES 4
#endif
/** DNS resource record max. TTL (one week as default) */
#ifndef DNS_MAX_TTL
#define DNS_MAX_TTL 604800
#endif
/* DNS protocol flags */
#define DNS_FLAG1_RESPONSE 0x84
#define DNS_FLAG1_OPCODE_STATUS 0x10
#define DNS_FLAG1_OPCODE_INVERSE 0x08
#define DNS_FLAG1_OPCODE_STANDARD 0x00
#define DNS_FLAG1_AUTHORATIVE 0x04
#define DNS_FLAG1_TRUNC 0x02
#define DNS_FLAG1_RD 0x01
#define DNS_FLAG2_RA 0x80
#define DNS_FLAG2_ERR_MASK 0x0f
#define DNS_FLAG2_ERR_NONE 0x00
#define DNS_FLAG2_ERR_NAME 0x03
/* DNS protocol states */
#define DNS_STATE_UNUSED 0
#define DNS_STATE_NEW 1
#define DNS_STATE_ASKING 2
#define DNS_STATE_DONE 3
/* MDNS registration type */
#define MDNS_HOSTNAME_REG 0
#define MDNS_SERVICE_REG 1
/* MDNS registration type */
#define MDNS_REG_ANSWER 1
#define MDNS_SD_ANSWER 2
#define MDNS_SERVICE_REG_ANSWER 3
/* MDNS registration time */
#define MDNS_HOST_TIME 120
#define MDNS_SERVICE_TIME 3600
/** MDNS name length with "." at the beginning and end of name*/
#ifndef MDNS_LENGTH_ADD
#define MDNS_LENGTH_ADD 2
#endif
#ifdef MDNS_MAX_NAME_LENGTH
#undef MDNS_MAX_NAME_LENGTH
#endif
#define MDNS_MAX_NAME_LENGTH (256)
PACK_STRUCT_BEGIN
/** DNS message header */
struct mdns_hdr {
PACK_STRUCT_FIELD(u16_t id);
PACK_STRUCT_FIELD(u8_t flags1);
PACK_STRUCT_FIELD(u8_t flags2);
PACK_STRUCT_FIELD(u16_t numquestions);
PACK_STRUCT_FIELD(u16_t numanswers);
PACK_STRUCT_FIELD(u16_t numauthrr);
PACK_STRUCT_FIELD(u16_t numextrarr);
}PACK_STRUCT_STRUCT;
PACK_STRUCT_END
#define SIZEOF_DNS_HDR 12
PACK_STRUCT_BEGIN
/** MDNS query message structure */
struct mdns_query {
/* MDNS query record starts with either a domain name or a pointer
to a name already present somewhere in the packet. */PACK_STRUCT_FIELD(u16_t type);
PACK_STRUCT_FIELD(u16_t class);
}PACK_STRUCT_STRUCT;
PACK_STRUCT_END
#define SIZEOF_DNS_QUERY 4
PACK_STRUCT_BEGIN
/** MDNS answer message structure */
struct mdns_answer {
/* MDNS answer record starts with either a domain name or a pointer
to a name already present somewhere in the packet. */PACK_STRUCT_FIELD(u16_t type);
PACK_STRUCT_FIELD(u16_t class);
PACK_STRUCT_FIELD(u32_t ttl);
PACK_STRUCT_FIELD(u16_t len);
}PACK_STRUCT_STRUCT;
PACK_STRUCT_END
#define SIZEOF_DNS_ANSWER 10
PACK_STRUCT_BEGIN
/** MDNS answer message structure */
struct mdns_a_rr {
PACK_STRUCT_FIELD(u32_t src);
}PACK_STRUCT_STRUCT;
PACK_STRUCT_END
#define SIZEOF_MDNS_A_RR 4
PACK_STRUCT_BEGIN
/** MDNS service registration message structure */
struct mdns_service {
PACK_STRUCT_FIELD(u16_t prior);
PACK_STRUCT_FIELD(u16_t weight);
PACK_STRUCT_FIELD(u16_t port);
}PACK_STRUCT_STRUCT;
PACK_STRUCT_END
#define SIZEOF_MDNS_SERVICE 6
static os_timer_t mdns_timer;
/* forward declarations */
static void mdns_recv(void *s, struct udp_pcb *pcb, struct pbuf *p,
struct ip_addr *addr, u16_t port);
/*-----------------------------------------------------------------------------
* Globales
*----------------------------------------------------------------------------*/
/* MDNS variables */
//static char puck_datasheet[PUCK_DATASHEET_SIZE];
static struct udp_pcb *mdns_pcb = NULL;
static struct nodemcu_mdns_info * ms_info = NULL;
static struct ip_addr multicast_addr;
static uint8 register_flag = 0;
static uint8 mdns_flag = 0;
static u8_t *mdns_payload;
/**
* Compare the "dotted" name "query" with the encoded name "response"
* to make sure an answer from the DNS server matches the current mdns_table
* entry (otherwise, answers might arrive late for hostname not on the list
* any more).
*
* @param query hostname (not encoded) from the mdns_table
* @param response encoded hostname in the DNS response
* @return 0: names equal; 1: names differ
*/
static u8_t ICACHE_FLASH_ATTR
mdns_compare_name(unsigned char *query, unsigned char *response, unsigned char *pktbase) {
unsigned char n;
do {
n = *response++;
/** @see RFC 1035 - 4.1.4. Message compression */
if ((n & 0xc0) == 0xc0) {
n = ((n << 8) + *response) & 0x3fff;
if (n < response - pktbase) {
response = pktbase + n;
} else {
return 1;
}
} else {
/* Not compressed name */
while (n > 0) {
char q = *query;
if (q >= 'A' && q <= 'Z') {
q = q + 'a' - 'A';
}
char r = *response;
if (r >= 'A' && r <= 'Z') {
r = r + 'a' - 'A';
}
if (q != r) {
return 1;
}
++response;
++query;
--n;
};
++query;
}
} while (*response != 0);
return 0;
}
static int
mdns_namelen(u8_t *p, unsigned int maxlen) {
u8_t *orig = p;
while (*p && *p <= 63) {
if (p - orig > maxlen) {
return -1;
}
p += *p + 1;
}
if (*p >= 0xc0) {
p += 2; // advance over the two byte pointer
} else {
p++; // advance over the final 0
}
if (p - orig > maxlen) {
return -1;
}
return p - orig;
}
/* Copy an unencoded name into an encoded name */
static unsigned char *copy_and_encode_name(unsigned char *ptr, const char *name) {
while (*name) {
const char *p = name;
while (*p != '.' && *p) {
p++;
}
*ptr++ = p - name;
memcpy(ptr, name, p - name);
ptr += p - name;
if (!*p) {
break;
}
name = p + 1;
}
*ptr++ = 0;
return ptr;
}
static err_t send_packet(struct pbuf *p, struct ip_addr *dst_addr, u16_t dst_port, u8_t *addr_ptr) {
err_t err;
/* send dns packet */
struct netif *sta_netif = (struct netif *)eagle_lwip_getif(0x00);
struct netif *ap_netif = (struct netif *)eagle_lwip_getif(0x01);
if (addr_ptr) {
if (wifi_get_opmode() == 0x02) {
if (!ap_netif) {
return;
}
memcpy(addr_ptr, &ap_netif->ip_addr, sizeof(ap_netif->ip_addr));
} else {
if (!sta_netif) {
return;
}
memcpy(addr_ptr, &sta_netif->ip_addr, sizeof(sta_netif->ip_addr));
}
}
if (dst_addr) {
err = udp_sendto(mdns_pcb, p, dst_addr, dst_port);
} else {
err = udp_sendto(mdns_pcb, p, &multicast_addr, DNS_MDNS_PORT);
if(wifi_get_opmode() == 0x03 && wifi_get_broadcast_if() == 0x03 &&\
sta_netif != NULL && ap_netif != NULL) {
if(netif_is_up(sta_netif) && netif_is_up(ap_netif)) {
netif_set_default(sta_netif);
if (addr_ptr) {
memcpy(addr_ptr, &ap_netif->ip_addr, sizeof(ap_netif->ip_addr));
}
err = udp_sendto(mdns_pcb, p, &multicast_addr, DNS_MDNS_PORT);
netif_set_default(ap_netif);
}
}
}
/* free pbuf */
pbuf_free(p);
return err;
}
/**
* Send a mDNS packet for the service type
*
* @param id transaction ID in the DNS query packet
* @return ERR_OK if packet is sent; an err_t indicating the problem otherwise
*/
static err_t ICACHE_FLASH_ATTR
mdns_send_service_type(u16_t id, struct ip_addr *dst_addr, u16_t dst_port) {
err_t err;
struct mdns_hdr *hdr;
struct mdns_answer ans;
struct mdns_a_rr a_rr;
struct mdns_service serv;
struct pbuf *p ,*p_sta;
char *query, *nptr;
const char *pHostname;
struct netif * sta_netif = NULL;
struct netif * ap_netif = NULL;
int max_ttl = dst_addr ? 10 : 7200;
char tmpBuf[PUCK_DATASHEET_SIZE + PUCK_SERVICE_LENGTH];
u8_t n;
u16_t length = 0;
/* if here, we have either a new query or a retry on a previous query to process */
p = pbuf_alloc(PBUF_TRANSPORT,
SIZEOF_DNS_HDR + MDNS_MAX_NAME_LENGTH * 2 + SIZEOF_DNS_QUERY, PBUF_RAM);
if (p != NULL) {
LWIP_ASSERT("pbuf must be in one piece", p->next == NULL);
/* fill dns header */
hdr = (struct mdns_hdr*) p->payload;
os_memset(hdr, 0, SIZEOF_DNS_HDR);
hdr->id = htons(id);
hdr->flags1 = DNS_FLAG1_RESPONSE;
pHostname = DNS_SD_SERVICE;
hdr->numanswers = htons(1);
query = (char*) hdr + SIZEOF_DNS_HDR;
--pHostname;
/* convert hostname into suitable query format. */
do {
++pHostname;
nptr = query;
++query;
for (n = 0; *pHostname != '.' && *pHostname != 0; ++pHostname) {
*query = *pHostname;
++query;
++n;
}
*nptr = n;
} while (*pHostname != 0);
*query++ = '\0';
/* fill dns query */
ans.type = htons(DNS_RRTYPE_PTR);
ans.class = htons(DNS_RRCLASS_IN);
ans.ttl = htonl(min(max_ttl, 3600));
ans.len = htons(os_strlen(service_name_with_suffix) + 1 +1 );
length = 0;
MEMCPY( query, &ans, SIZEOF_DNS_ANSWER);
/* resize the query */
query = query + SIZEOF_DNS_ANSWER;
pHostname = service_name_with_suffix;
--pHostname;
/* convert hostname into suitable query format. */
do {
++pHostname;
nptr = query;
++query;
for (n = 0; *pHostname != '.' && *pHostname != 0; ++pHostname) {
*query = *pHostname;
++query;
++n;
}
*nptr = n;
} while (*pHostname != 0);
*query++ = '\0';
/* resize pbuf to the exact dns query */
pbuf_realloc(p, (query + length) - ((char*) (p->payload)));
err = send_packet(p, dst_addr, dst_port, 0);
} else {
err = ERR_MEM;
}
return err;
}
/**
* Send a mDNS service answer packet.
*
* @param name service name to query
* @param id transaction ID in the DNS query packet
* @return ERR_OK if packet is sent; an err_t indicating the problem otherwise
*/
static err_t ICACHE_FLASH_ATTR
mdns_send_service(struct nodemcu_mdns_info *info, u16_t id, struct ip_addr *dst_addr, u16_t dst_port) {
err_t err;
struct mdns_hdr *hdr;
struct mdns_answer ans;
struct mdns_service serv;
struct mdns_a_rr a_rr;
struct pbuf *p ,*p_sta;
char *query, *nptr;
char *query_end;
const char *pHostname;
const char *name = info->host_name;
int max_ttl = dst_addr ? 10 : 7200;
u8_t n;
u8_t i = 0;
u16_t length = 0;
u8_t addr1 = 12, addr2 = 12;
struct netif * sta_netif = NULL;
struct netif * ap_netif = NULL;
char tmpBuf[PUCK_DATASHEET_SIZE + PUCK_SERVICE_LENGTH];
u16_t dns_class = dst_addr ? DNS_RRCLASS_IN : DNS_RRCLASS_FLUSH_IN;
/* if here, we have either a new query or a retry on a previous query to process */
p = pbuf_alloc(PBUF_TRANSPORT,
SIZEOF_DNS_HDR + MDNS_MAX_NAME_LENGTH * 2 + SIZEOF_DNS_QUERY, PBUF_RAM);
if (p != NULL) {
LWIP_ASSERT("pbuf must be in one piece", p->next == NULL);
/* fill dns header */
hdr = (struct mdns_hdr*) p->payload;
os_memset(hdr, 0, SIZEOF_DNS_HDR);
hdr->id = htons(id);
hdr->flags1 = DNS_FLAG1_RESPONSE;
hdr->numanswers = htons(4);
hdr->numextrarr = htons(1);
query = (char*) hdr + SIZEOF_DNS_HDR;
query_end = (char *) p->payload + p->tot_len;
c_strlcpy(tmpBuf, service_name_with_suffix, sizeof(tmpBuf));
pHostname = tmpBuf;
--pHostname;
/* convert hostname into suitable query format. */
do {
++pHostname;
nptr = query;
++query;
++addr1;
++addr2;
for (n = 0; *pHostname != '.' && *pHostname != 0; ++pHostname) {
*query = *pHostname;
++query;
++addr1;
++addr2;
++n;
}
*nptr = n;
} while (*pHostname != 0);
*query++ = '\0';
length = sizeof(MDNS_LOCAL);
addr1 -= length;
length = os_strlen(service_name_with_suffix) + 1;
addr2 -= length;
ans.type = htons(DNS_RRTYPE_PTR);
ans.class = htons(DNS_RRCLASS_IN);
ans.ttl = htonl(min(max_ttl, 300));
length = os_strlen(ms_info->host_desc) + MDNS_LENGTH_ADD + 1;
ans.len = htons(length);
length = 0;
MEMCPY( query, &ans, SIZEOF_DNS_ANSWER);
/* resize the query */
query = query + SIZEOF_DNS_ANSWER;
int name_offset = query - (const char *) hdr;
pHostname = ms_info->host_desc;
--pHostname;
/* convert hostname into suitable query format. */
do {
++pHostname;
nptr = query;
++query;
for (n = 0; *pHostname != '.' && *pHostname != 0; ++pHostname) {
*query = *pHostname;
++query;
++n;
}
*nptr = n;
} while (*pHostname != 0);
*query++ = DNS_OFFSET_FLAG;
*query++ = DNS_DEFAULT_OFFSET;
*query++ = 0xc0 + (name_offset >> 8);
*query++ = name_offset & 0xff;
/* fill the answer */
ans.type = htons(DNS_RRTYPE_TXT);
ans.class = htons(dns_class);
ans.ttl = htonl(min(max_ttl, 300));
// length = os_strlen(TXT_DATA) + MDNS_LENGTH_ADD + 1;
const char *attributes[12];
int attr_count = 0;
for(i = 0; i < 10 && (info->txt_data[i] != NULL); i++) {
length += os_strlen(info->txt_data[i]);
length++;
attributes[attr_count++] = info->txt_data[i];
}
//MDNS_DBG("Found %d user attributes\n", i);
static const char *defaults[] = { "platform=nodemcu", NULL };
for(i = 0; defaults[i] != NULL; i++) {
// See if this is a duplicate
int j;
int len = strchr(defaults[i], '=') + 1 - defaults[i];
for (j = 0; j < attr_count; j++) {
if (strncmp(attributes[j], defaults[i], len) == 0) {
break;
}
}
if (j == attr_count) {
length += os_strlen(defaults[i]);
length++;
attributes[attr_count++] = defaults[i];
}
}
//MDNS_DBG("Found %d total attributes\n", attr_count);
ans.len = htons(length);
MEMCPY( query, &ans, SIZEOF_DNS_ANSWER);
query = query + SIZEOF_DNS_ANSWER;
// Check enough space in the packet
const char *end_of_packet = query + length + 2 + SIZEOF_DNS_ANSWER + SIZEOF_MDNS_SERVICE +
os_strlen(ms_info->host_name) + 7 + 1 + 2 + SIZEOF_DNS_ANSWER + SIZEOF_MDNS_A_RR +
2 + SIZEOF_DNS_ANSWER + 5;
if (query_end <= end_of_packet) {
MDNS_DBG("Too much data to send\n");
pbuf_free(p);
return ERR_MEM;
}
//MDNS_DBG("Query=%x, query_end=%x, end_ofpacket=%x, length=%x\n", query, query_end, end_of_packet, length);
i = 0;
while(attributes[i] != NULL && i < attr_count) {
pHostname = attributes[i];
--pHostname;
/* convert hostname into suitable query format. */
do {
++pHostname;
nptr = query;
++query;
for (n = 0; *pHostname != 0; ++pHostname) {
*query = *pHostname;
++query;
++n;
}
*nptr = n;
} while (*pHostname != 0);
i++;
}
// *query++ = '\0';
// Increment by length
*query++ = 0xc0 + (name_offset >> 8);
*query++ = name_offset & 0xff;
// Increment by 2
ans.type = htons(DNS_RRTYPE_SRV);
ans.class = htons(dns_class);
ans.ttl = htonl(min(max_ttl, 300));
c_strlcpy(tmpBuf,ms_info->host_name, sizeof(tmpBuf));
c_strlcat(tmpBuf, ".", sizeof(tmpBuf));
c_strlcat(tmpBuf, MDNS_LOCAL, sizeof(tmpBuf));
length = os_strlen(tmpBuf) + MDNS_LENGTH_ADD;
ans.len = htons(SIZEOF_MDNS_SERVICE + length);
length = 0;
MEMCPY( query, &ans, SIZEOF_DNS_ANSWER);
/* resize the query */
query = query + SIZEOF_DNS_ANSWER;
serv.prior = htons(0);
serv.weight = htons(0);
serv.port = htons(ms_info->service_port);
MEMCPY( query, &serv, SIZEOF_MDNS_SERVICE);
/* resize the query */
query = query + SIZEOF_MDNS_SERVICE;
int hostname_offset = query - (const char *) hdr;
pHostname = tmpBuf;
--pHostname;
do {
++pHostname;
nptr = query;
++query;
for (n = 0; *pHostname != '.' && *pHostname != 0; ++pHostname) {
*query = *pHostname;
++query;
++n;
}
*nptr = n;
} while (*pHostname != 0);
*query++ = '\0';
// increment by strlen(service_name) + 1 + 7 + sizeof_dns_answer + sizeof_mdns_service
*query++ = 0xc0 + (hostname_offset >> 8);
*query++ = hostname_offset & 0xff;
ans.type = htons(DNS_RRTYPE_A);
ans.class = htons(dns_class);
ans.ttl = htonl(min(max_ttl, 300));
ans.len = htons(DNS_IP_ADDR_LEN);
MEMCPY( query, &ans, SIZEOF_DNS_ANSWER);
/* resize the query */
query = query + SIZEOF_DNS_ANSWER;
// increment by strlen(service_name) + 1 + 7 + sizeof_dns_answer
/* fill the payload of the mDNS message */
/* set the local IP address */
a_rr.src = 0;
MEMCPY( query, &a_rr, SIZEOF_MDNS_A_RR);
u8_t *addr_ptr = query + ((char *) &a_rr.src - (char *) &a_rr);
/* resize the query */
query = query + SIZEOF_MDNS_A_RR;
// Append the NSEC record that says we only have an A record
*query++ = 0xc0 + (hostname_offset >> 8);
*query++ = hostname_offset & 0xff;
ans.type = htons(DNS_RRTYPE_NSEC);
ans.class = htons(dns_class);
ans.ttl = htonl(min(max_ttl, 300));
ans.len = htons(5);
MEMCPY( query, &ans, SIZEOF_DNS_ANSWER);
query = query + SIZEOF_DNS_ANSWER;
*query++ = 0xc0 + (hostname_offset >> 8);
*query++ = hostname_offset & 0xff;
*query++ = 0;
*query++ = 1;
*query++ = 0x40;
//MDNS_DBG("Final ptr=%x\n", query);
// increment by sizeof_mdns_a_rr
/* set the name of the authority field.
* The same name as the Query using the offset address*/
/* resize pbuf to the exact dns query */
pbuf_realloc(p, (query) - ((char*) (p->payload)));
err = send_packet(p, dst_addr, dst_port, addr_ptr);
if (!dst_addr) {
// this is being sent multicast...
// so reset the timer
os_timer_disarm(&mdns_timer);
os_timer_arm(&mdns_timer, 1000 * 280, 1);
}
} else {
MDNS_DBG("ERR_MEM \n");
err = ERR_MEM;
}
return err;
}
static char *append_nsec_record(char *query, u32_t actual_rr, int max_ttl) {
struct mdns_answer ans;
ans.type = htons(DNS_RRTYPE_NSEC);
ans.class = htons(DNS_RRCLASS_IN);
ans.ttl = htonl(min(max_ttl, 300));
ans.len = htons(9);
MEMCPY( query, &ans, SIZEOF_DNS_ANSWER);
char *rr_len = query + ((char *) &ans.len - (char *) &ans) + 1;
query = query + SIZEOF_DNS_ANSWER;
*query++ = 0xc0;
*query++ = sizeof(struct mdns_hdr);
*query++ = 0;
char *bm_len = query;
*query++ = 5;
char *abase = query;
*query++ = 0;
*query++ = 0;
*query++ = 0;
*query++ = 0;
*query++ = 0;
while (actual_rr > 0) {
int v = actual_rr & 255;
if (v < 5 * 8) {
abase[v >> 3] |= 0x80 >> (v & 7);
actual_rr = actual_rr >> 8;
}
}
while (query[-1] == 0) {
query--;
(*bm_len)--;
(*rr_len)--;
}
return query;
}
/**
* This sends an empty response -- this is used when we doin't have an RR to send
* but the name exists
*/
static void
mdns_send_no_rr(struct mdns_hdr *req, const char *name, u32_t actual_rr, struct ip_addr *dst_addr, u16_t dst_port) {
int max_ttl = dst_addr ? 10 : 7200;
struct pbuf *p;
p = pbuf_alloc(PBUF_TRANSPORT,
SIZEOF_DNS_HDR + MDNS_MAX_NAME_LENGTH * 2 + SIZEOF_DNS_QUERY, PBUF_RAM);
if (p != NULL) {
LWIP_ASSERT("pbuf must be in one piece", p->next == NULL);
/* fill dns header */
struct mdns_hdr *hdr = (struct mdns_hdr*) p->payload;
os_memset(hdr, 0, SIZEOF_DNS_HDR);
hdr->id = req->id;
hdr->flags1 = DNS_FLAG1_RESPONSE;
hdr->numextrarr = htons(1);
char *query = (char*) hdr + SIZEOF_DNS_HDR;
char *query_end = (char *) p->payload + p->tot_len;
// Now copy over the dns name
int len = strlen(name);
if (query_end - query >= len + SIZEOF_DNS_QUERY + 15) {
query = copy_and_encode_name((char *) (hdr + 1), name);
query = append_nsec_record(query, actual_rr, max_ttl);
// Set the length code correctly
pbuf_realloc(p, query - ((char*) (p->payload)));
send_packet(p, dst_addr, dst_port, NULL);
}
}
}
/**
* This sends a single A record and the NSEC record as additional
*/
static void
mdns_send_a_rr(struct mdns_hdr *req, const char *name, struct ip_addr *dst_addr, u16_t dst_port) {
int max_ttl = dst_addr ? 10 : 7200;
struct pbuf *p;
p = pbuf_alloc(PBUF_TRANSPORT,
SIZEOF_DNS_HDR + MDNS_MAX_NAME_LENGTH * 2 + SIZEOF_DNS_QUERY, PBUF_RAM);
if (p != NULL) {
LWIP_ASSERT("pbuf must be in one piece", p->next == NULL);
/* fill dns header */
struct mdns_hdr *hdr = (struct mdns_hdr*) p->payload;
os_memset(hdr, 0, SIZEOF_DNS_HDR);
hdr->id = req->id;
hdr->flags1 = DNS_FLAG1_RESPONSE;
hdr->numanswers = htons(1);
hdr->numextrarr = htons(1);
char *query = (char*) hdr + SIZEOF_DNS_HDR;
char *query_end = (char *) p->payload + p->tot_len;
// Now copy over the dns name
int len = strlen(name) + 1;
if (query_end - query >= len + SIZEOF_DNS_QUERY + 4 + 2 + 4 + 15) {
query = copy_and_encode_name((char *) (hdr + 1), name);
struct mdns_answer ans;
ans.type = htons(DNS_RRTYPE_A);
ans.class = htons(DNS_RRCLASS_IN);
ans.ttl = htonl(min(max_ttl, 300));
ans.len = htons(4);
MEMCPY( query, &ans, SIZEOF_DNS_ANSWER);
query = query + SIZEOF_DNS_ANSWER;
char *addr_ptr = query;
query += 4;
// Now add the NSEC record
*query++ = 0xc0;
*query++ = sizeof(*hdr);
query = append_nsec_record(query, DNS_RRTYPE_A, max_ttl);
// Set the length code correctly
pbuf_realloc(p, query - ((char*) (p->payload)));
send_packet(p, dst_addr, dst_port, addr_ptr);
}
}
}
/**
* Receive input function for DNS response packets arriving for the dns UDP pcb.
*
* @params see udp.h
*/
static void ICACHE_FLASH_ATTR
mdns_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr,
u16_t port) {
u16_t i;
struct mdns_hdr *hdr;
u8_t nquestions;
LWIP_UNUSED_ARG(arg);
LWIP_UNUSED_ARG(pcb);
struct nodemcu_mdns_info *info = (struct nodemcu_mdns_info *)arg;
/* is the dns message too big ? */
if (p->tot_len > DNS_MSG_SIZE) {
LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: pbuf too big\n"));
/* free pbuf and return */
goto memerr1;
}
/* is the dns message big enough ? */
if (p->tot_len < (SIZEOF_DNS_HDR + SIZEOF_DNS_QUERY + SIZEOF_DNS_ANSWER)) {
LWIP_DEBUGF(DNS_DEBUG, ("dns_recv: pbuf too small\n"));
/* free pbuf and return */
goto memerr1;
}
/* copy dns payload inside static buffer for processing */
if (pbuf_copy_partial(p, mdns_payload, p->tot_len, 0) == p->tot_len) {
/* The ID in the DNS header should be our entry into the name table. */
hdr = (struct mdns_hdr*) mdns_payload;
i = htons(hdr->id);
nquestions = htons(hdr->numquestions);
//nanswers = htons(hdr->numanswers);
/* if we have a question send an answer if necessary */
u8_t qno;
u8_t *qptr = (u8_t *) (hdr + 1);
u8_t *qend = mdns_payload + p->tot_len;
for (qno = 0; qno < nquestions && qptr < qend; qno++) {
char tmpBuf[PUCK_DATASHEET_SIZE + PUCK_SERVICE_LENGTH];
struct mdns_query qry;
int namelen = mdns_namelen(qptr, qend - qptr);
memcpy(&qry, namelen + qptr, sizeof(qry));
u16_t qry_type = ntohs(qry.type);
if (port == 5353 && (ntohs(qry.class) & 0x8000) == 0) {
addr = NULL;
}
u32_t actual_rr = 0;
const char *no_rr_name = NULL;
/* MDNS_DS_DOES_NAME_CHECK */
/* Check if the name in the "question" part match with the name of the MDNS DS service. */
if (mdns_compare_name((unsigned char *) DNS_SD_SERVICE,
(unsigned char *) qptr, (unsigned char *) hdr) == 0) {
if (qry_type == DNS_RRTYPE_PTR || qry_type == DNS_RRTYPE_ANY) {
mdns_send_service_type(i, addr, port);
} else {
no_rr_name = DNS_SD_SERVICE;
actual_rr = DNS_RRTYPE_PTR;
}
} else if (mdns_compare_name((unsigned char *) service_name_with_suffix,
(unsigned char *) qptr, (unsigned char *) hdr) == 0) {
if (qry_type == DNS_RRTYPE_PTR || qry_type == DNS_RRTYPE_ANY) {
mdns_send_service(info, i, addr, port);
} else {
no_rr_name = service_name_with_suffix;
actual_rr = DNS_RRTYPE_PTR;
}
} else {
c_strlcpy(tmpBuf,ms_info->host_name, sizeof(tmpBuf));
c_strlcat(tmpBuf, ".", sizeof(tmpBuf));
c_strlcat(tmpBuf, MDNS_LOCAL, sizeof(tmpBuf));
no_rr_name = tmpBuf;
if (mdns_compare_name((unsigned char *) tmpBuf,
(unsigned char *) qptr, (unsigned char *) hdr) == 0) {
if (qry_type == DNS_RRTYPE_A || qry_type == DNS_RRTYPE_ANY) {
mdns_send_a_rr(hdr, tmpBuf, addr, port);
} else {
actual_rr = DNS_RRTYPE_A;
}
} else {
c_strlcpy(tmpBuf,ms_info->host_desc, sizeof(tmpBuf));
c_strlcat(tmpBuf, ".", sizeof(tmpBuf));
c_strlcat(tmpBuf, service_name_with_suffix, sizeof(tmpBuf));
if (mdns_compare_name((unsigned char *) tmpBuf,
(unsigned char *) qptr, (unsigned char *) hdr) == 0) {
if (qry_type == DNS_RRTYPE_TXT || qry_type == DNS_RRTYPE_SRV || qry_type == DNS_RRTYPE_ANY) {
mdns_send_service(info, i, addr, port);
} else {
actual_rr = (DNS_RRTYPE_TXT << 8) + DNS_RRTYPE_SRV;
}
}
}
}
if (actual_rr) {
mdns_send_no_rr(hdr, no_rr_name, actual_rr, addr, port);
}
qptr += namelen + sizeof(qry); // Now points to next question
}
}
memerr1:
/* free pbuf */
pbuf_free(p);
return;
}
static void
mdns_free_info(struct nodemcu_mdns_info *info) {
os_free((void *) info);
}
/**
* close the UDP pcb .
*/
void ICACHE_FLASH_ATTR
nodemcu_mdns_close(void)
{
os_timer_disarm(&mdns_timer);
if (mdns_pcb != NULL) {
udp_remove(mdns_pcb);
}
if (mdns_payload) {
os_free(mdns_payload);
}
mdns_payload = NULL;
mdns_pcb = NULL;
mdns_free_info(ms_info);
ms_info = NULL;
}
static void ICACHE_FLASH_ATTR
mdns_set_servicename(const char *name) {
char tmpBuf[128];
os_sprintf(tmpBuf, "_%s._tcp.local", name);
if (service_name_with_suffix) {
os_free(service_name_with_suffix);
}
service_name_with_suffix = c_strdup(tmpBuf);
}
static u8_t reg_counter;
static void
mdns_reg_handler_restart(void) {
reg_counter = 99;
}
static void ICACHE_FLASH_ATTR
mdns_reg(struct nodemcu_mdns_info *info) {
mdns_send_service(info,0,0,0);
if (reg_counter++ > 10) {
mdns_send_service_type(0,0,0);
reg_counter = 0;
}
}
static struct nodemcu_mdns_info *
mdns_dup_info(const struct nodemcu_mdns_info *info) {
struct nodemcu_mdns_info *result;
// calculate length
int len = sizeof(struct nodemcu_mdns_info);
len += c_strlen(info->host_name) + 1;
len += c_strlen(info->host_desc) + 1;
len += c_strlen(info->service_name) + 1;
int i;
for (i = 0; i < sizeof(info->txt_data) / sizeof(info->txt_data[0]) && info->txt_data[i]; i++) {
len += c_strlen(info->txt_data[i]) + 1;
}
#define COPY_OVER(dest, src, p) len = c_strlen(src) + 1; memcpy(p, src, len); dest = p; p += len
result = (struct nodemcu_mdns_info *) os_zalloc(len);
if (result) {
char *p = (char *) (result + 1);
result->service_port = info->service_port;
COPY_OVER(result->host_name, info->host_name, p);
COPY_OVER(result->host_desc, info->host_desc, p);
COPY_OVER(result->service_name, info->service_name, p);
for (i = 0; i < sizeof(info->txt_data) / sizeof(info->txt_data[0]) && info->txt_data[i]; i++) {
COPY_OVER(result->txt_data[i], info->txt_data[i], p);
}
}
#undef COPY_OVER
return result;
}
/**
* Initialize the resolver: set up the UDP pcb and configure the default server
* (NEW IP).
*
* returns TRUE if it worked, FALSE if it failed.
*/
bool ICACHE_FLASH_ATTR
nodemcu_mdns_init(struct nodemcu_mdns_info *info) {
/* initialize default DNS server address */
multicast_addr.addr = DNS_MULTICAST_ADDRESS;
struct ip_info ipconfig;
mdns_free_info(ms_info);
ms_info = mdns_dup_info(info); // Save the passed block. We need all the data forever
if (!ms_info) {
return FALSE;
}
if (mdns_payload) {
os_free(mdns_payload);
}
mdns_payload = (u8_t *) os_malloc(DNS_MSG_SIZE);
if (!mdns_payload) {
MDNS_DBG("Alloc fail\n");
return FALSE;
}
LWIP_DEBUGF(DNS_DEBUG, ("dns_init: initializing\n"));
mdns_set_servicename(ms_info->service_name);
// get the host name as instrumentName_serialNumber for MDNS
// set the name of the service, the same as host name
MDNS_DBG("host_name = %s\n", ms_info->host_name);
MDNS_DBG("server_name = %s\n", service_name_with_suffix);
/* initialize mDNS */
mdns_pcb = udp_new();
if (!mdns_pcb) {
return FALSE;
}
/* join to the multicast address 224.0.0.251 */
if(wifi_get_opmode() & 0x01) {
struct netif *sta_netif = (struct netif *)eagle_lwip_getif(0x00);
if (sta_netif && sta_netif->ip_addr.addr && igmp_joingroup(&sta_netif->ip_addr, &multicast_addr) != ERR_OK) {
MDNS_DBG("sta udp_join_multigrup failed!\n");
return FALSE;
};
}
if(wifi_get_opmode() & 0x02) {
struct netif *ap_netif = (struct netif *)eagle_lwip_getif(0x01);
if (ap_netif && ap_netif->ip_addr.addr && igmp_joingroup(&ap_netif->ip_addr, &multicast_addr) != ERR_OK) {
MDNS_DBG("ap udp_join_multigrup failed!\n");
return FALSE;
};
}
register_flag = 1;
/* join to any IP address at the port 5353 */
if (udp_bind(mdns_pcb, IP_ADDR_ANY, DNS_MDNS_PORT) != ERR_OK) {
MDNS_DBG("udp_bind failed!\n");
return FALSE;
};
/*loopback function for the multicast(224.0.0.251) messages received at port 5353*/
udp_recv(mdns_pcb, mdns_recv, ms_info);
mdns_flag = 1;
/*
* Register the name of the instrument
*/
//MDNS_DBG("About to start timer\n");
os_timer_disarm(&mdns_timer);
os_timer_setfn(&mdns_timer, (os_timer_func_t *)mdns_reg,ms_info);
os_timer_arm(&mdns_timer, 1000 * 280, 1);
/* kick off the first one right away */
mdns_reg_handler_restart();
mdns_reg(ms_info);
return TRUE;
}
#endif /* LWIP_MDNS */