Merge pull request #3093 from cesanta/mdns-multicast

Added MDNS and driver support for multicast

Author: scaprile

mongoose.c

@@ -499,6 +499,20 @@ typedef enum { false = 0, true = 1 } bool;
 #pragma comment(lib, "advapi32.lib")
 #endif
 
+#if defined(_MSC_VER) && _MSC_VER <= 1200
+  #ifndef IPPROTO_IP
+    #define IPPROTO_IP 0
+  #endif
+
+  #ifndef IP_ADD_MEMBERSHIP
+    struct ip_mreq {
+        struct in_addr imr_multiaddr;
+        struct in_addr imr_interface;
+    };
+    #define IP_ADD_MEMBERSHIP  12
+  #endif
+#endif
+
 // Protect from calls like std::snprintf in app code
 // See https://github.com/cesanta/mongoose/issues/1047
 #ifndef __cplusplus
@@ -2655,6 +2669,8 @@ void mg_resolve_cancel(struct mg_connection *);
 bool mg_dns_parse(const uint8_t *buf, size_t len, struct mg_dns_message *);
 size_t mg_dns_parse_rr(const uint8_t *buf, size_t len, size_t ofs,
                        bool is_question, struct mg_dns_rr *);
+                       
+struct mg_connection *mg_mdns_listen(struct mg_mgr *mgr, char *name);
 
 
 
@@ -2803,6 +2819,8 @@ bool mg_wifi_ap_start(char *ssid, char *pass, unsigned int channel);
 bool mg_wifi_ap_stop(void);
 
 
+#if MG_ENABLE_TCPIP
+
 
 
 
@@ -2833,7 +2851,6 @@ enum {
   MG_TCPIP_EV_USER              // Starting ID for user events
 };
 
-
 // Network interface
 struct mg_tcpip_if {
   uint8_t mac[6];                  // MAC address. Must be set to a valid MAC
@@ -2846,6 +2863,7 @@ struct mg_tcpip_if {
   bool enable_req_sntp;            // DCHP client requests SNTP server
   bool enable_crc32_check;         // Do a CRC check on RX frames and strip it
   bool enable_mac_check;           // Do a MAC check on RX frames
+  bool update_mac_hash_table;      // Signal drivers to update MAC controller
   struct mg_tcpip_driver *driver;  // Low level driver
   void *driver_data;               // Driver-specific data
   mg_tcpip_event_handler_t fn;     // User-specified event handler function
@@ -2903,6 +2921,8 @@ struct mg_tcpip_spi {
   uint8_t (*txn)(void *, uint8_t);  // SPI transaction: write 1 byte, read reply
 };
 
+#endif
+
 
 
 // Macros to record timestamped events that happens with a connection.

mongoose.h

@@ -77,6 +77,20 @@ typedef enum { false = 0, true = 1 } bool;
 #pragma comment(lib, "advapi32.lib")
 #endif
 
+#if defined(_MSC_VER) && _MSC_VER <= 1200
+  #ifndef IPPROTO_IP
+    #define IPPROTO_IP 0
+  #endif
+
+  #ifndef IP_ADD_MEMBERSHIP
+    struct ip_mreq {
+        struct in_addr imr_multiaddr;
+        struct in_addr imr_interface;
+    };
+    #define IP_ADD_MEMBERSHIP  12
+  #endif
+#endif
+
 // Protect from calls like std::snprintf in app code
 // See https://github.com/cesanta/mongoose/issues/1047
 #ifndef __cplusplus

src/arch_win32.h

@@ -100,6 +100,7 @@ bool mg_dns_parse(const uint8_t *buf, size_t len, struct mg_dns_message *dm) {
   const struct mg_dns_header *h = (struct mg_dns_header *) buf;
   struct mg_dns_rr rr;
   size_t i, n, num_answers, ofs = sizeof(*h);
+  bool is_response;
   memset(dm, 0, sizeof(*dm));
 
   if (len < sizeof(*h)) return 0;                // Too small, headers dont fit
@@ -110,12 +111,22 @@ bool mg_dns_parse(const uint8_t *buf, size_t len, struct mg_dns_message *dm) {
     num_answers = 10;  // Sanity cap
   }
   dm->txnid = mg_ntohs(h->txnid);
+  is_response = mg_ntohs(h->flags) & 0x8000;
 
   for (i = 0; i < mg_ntohs(h->num_questions); i++) {
     if ((n = mg_dns_parse_rr(buf, len, ofs, true, &rr)) == 0) return false;
     // MG_INFO(("Q %lu %lu %hu/%hu", ofs, n, rr.atype, rr.aclass));
+    mg_dns_parse_name(buf, len, ofs, dm->name, sizeof(dm->name));
     ofs += n;
   }
+
+  if (!is_response) {
+    // For queries, there is no need to parse the answers. In this way,
+    // we also ensure the domain name (dm->name) is parsed from
+    // the question field.
+    return true;
+  }
+
   for (i = 0; i < num_answers; i++) {
     if ((n = mg_dns_parse_rr(buf, len, ofs, false, &rr)) == 0) return false;
     // MG_INFO(("A -- %lu %lu %hu/%hu %s", ofs, n, rr.atype, rr.aclass,
@@ -265,3 +276,72 @@ void mg_resolve(struct mg_connection *c, const char *url) {
     mg_sendnsreq(c, &host, c->mgr->dnstimeout, dns, c->mgr->use_dns6);
   }
 }
+
+static const uint8_t mdns_answer[] = {
+    0, 1,          // 2 bytes - record type, A
+    0, 1,          // 2 bytes - address class, INET
+    0, 0, 0, 120,  // 4 bytes - TTL
+    0, 4           // 2 bytes - address length
+};
+
+static void mdns_cb(struct mg_connection *c, int ev, void *ev_data) {
+  if (ev == MG_EV_READ) {
+    struct mg_dns_header *qh = (struct mg_dns_header *) c->recv.buf;
+    if (c->recv.len > 12 && (qh->flags & mg_htons(0xF800)) == 0) {
+      // flags -> !resp, opcode=0 => query; ignore other opcodes and responses
+      struct mg_dns_rr rr;  // Parse first question, offset 12 is header size
+      size_t n = mg_dns_parse_rr(c->recv.buf, c->recv.len, 12, true, &rr);
+      MG_VERBOSE(("mDNS request parsed, result=%d", (int) n));
+      if (n > 0) {
+        // RFC-6762 Appendix C, RFC2181 11: m(n + 1-63), max 255 + 0x0
+        // buf and h declared here to ease future expansion to DNS-SD
+        uint8_t buf[sizeof(struct mg_dns_header) + 256 + sizeof(mdns_answer) + 4];
+        struct mg_dns_header *h = (struct mg_dns_header *) buf;
+        char local_name[63 + 7];  // name label + '.' + local label + '\0'
+        uint8_t name_len = (uint8_t) strlen((char *)c->fn_data);
+        struct mg_dns_message dm;
+        bool unicast = (rr.aclass & MG_BIT(15)) != 0;  // QU
+        // uint16_t q = mg_ntohs(qh->num_questions);
+        rr.aclass &= (uint16_t) ~MG_BIT(15);  // remove "QU" (unicast response)
+        qh->num_questions = mg_htons(1);      // parser sanity
+        mg_dns_parse(c->recv.buf, c->recv.len, &dm);
+        if (name_len > (sizeof(local_name) - 7))  // leave room for .local\0
+          name_len = sizeof(local_name) - 7;
+        memcpy(local_name, c->fn_data, name_len);
+        strcpy(local_name + name_len, ".local");  // ensure proper name.local\0
+        if (strcmp(local_name, dm.name) == 0) {
+          uint8_t *p = &buf[sizeof(*h)];
+          memset(h, 0, sizeof(*h));            // clear header
+          h->txnid = unicast ? qh->txnid : 0;  // RFC-6762 18.1
+          // RFC-6762 6: 0 questions, 1 Answer, 0 Auth, 0 Additional RRs
+          h->num_answers = mg_htons(1);  // only one answer
+          h->flags = mg_htons(0x8400);   // Authoritative response
+          *p++ = name_len;               // label 1
+          memcpy(p, c->fn_data, name_len), p += name_len;
+          *p++ = 5;  // label 2
+          memcpy(p, "local", 5), p += 5;
+          *p++ = 0;  // no more labels
+          memcpy(p, mdns_answer, sizeof(mdns_answer)), p += sizeof(mdns_answer);
+#if MG_ENABLE_TCPIP
+          memcpy(p, &c->mgr->ifp->ip, 4), p += 4;
+#else
+          memcpy(p, c->data, 4), p += 4;
+#endif
+          if (!unicast) memcpy(&c->rem, &c->loc, sizeof(c->rem));
+          mg_send(c, buf, (size_t)(p - buf));  // And send it!
+          MG_DEBUG(("mDNS %c response sent", unicast ? 'U' : 'M'));
+        }
+      }
+    }
+    mg_iobuf_del(&c->recv, 0, c->recv.len);
+  }
+  (void) ev_data;
+}
+
+void mg_multicast_add(struct mg_connection *c, char *ip);
+struct mg_connection *mg_mdns_listen(struct mg_mgr *mgr, char *name) {
+  struct mg_connection *c =
+      mg_listen(mgr, "udp://224.0.0.251:5353", mdns_cb, name);
+  if (c != NULL) mg_multicast_add(c, (char *)"224.0.0.251");
+  return c;
+}

src/dns.c

@@ -36,3 +36,5 @@ void mg_resolve_cancel(struct mg_connection *);
 bool mg_dns_parse(const uint8_t *buf, size_t len, struct mg_dns_message *);
 size_t mg_dns_parse_rr(const uint8_t *buf, size_t len, size_t ofs,
                        bool is_question, struct mg_dns_rr *);
+                       
+struct mg_connection *mg_mdns_listen(struct mg_mgr *mgr, char *name);

src/dns.h

@@ -56,7 +56,20 @@ static size_t cmsis_tx(const void *buf, size_t len, struct mg_tcpip_if *ifp) {
   return len;
 }
 
+static void cmsis_update_hash_table(struct mg_tcpip_if *ifp) {
+  // TODO(): read database, rebuild hash table
+  ARM_DRIVER_ETH_MAC *mac = &Driver_ETH_MAC0;
+  ARM_ETH_MAC_ADDR addr;
+  memcpy(&addr, mcast_addr, sizeof(addr));
+  mac->SetAddressFilter(&addr, 1);
+  (void) ifp;
+}
+
 static bool cmsis_poll(struct mg_tcpip_if *ifp, bool s1) {
+  if (ifp->update_mac_hash_table) {
+    cmsis_update_hash_table(ifp);
+    ifp->update_mac_hash_table = false;
+  }
   if (!s1) return false;
   ARM_DRIVER_ETH_PHY *phy = &Driver_ETH_PHY0;
   ARM_DRIVER_ETH_MAC *mac = &Driver_ETH_MAC0;

src/drivers/cmsis.c

@@ -140,12 +140,18 @@ static void cyw_handle_bdc(struct bdc_hdr *bdc, size_t len);
 static void cyw_handle_bdc_evnt(struct bdc_hdr *bdc, size_t len);
 
 static size_t cyw_spi_poll(uint8_t *dest);
+static void cyw_update_hash_table(void);
 
 // High-level comm stuff
 
 static void cyw_poll(void) {
   struct sdpcm_hdr *sdpcm = (struct sdpcm_hdr *) resp;
   unsigned int channel;
+  if (s_ifp->update_mac_hash_table) {
+    // first call to _poll() is after _init(), so this is safe
+    cyw_update_hash_table();
+    s_ifp->update_mac_hash_table = false;
+  }
   if (cyw_spi_poll((uint8_t *) resp) == 0) return;  // BUS DEPENDENCY
   if ((sdpcm->len ^ sdpcm->_len) != 0xffff || sdpcm->len < sizeof(*sdpcm) ||
       sdpcm->len > 2048 - sizeof(*sdpcm))
@@ -822,6 +828,13 @@ static bool cyw_load_clm(struct mg_tcpip_driver_cyw_firmware *fw) {
   return cyw_load_clmll((void *) fw->clm_addr, fw->clm_len);
 }
 
+static void cyw_update_hash_table(void) {
+  // TODO(): read database, rebuild hash table
+  uint32_t val = 0;
+  val = 1; cyw_ioctl_iovar_set2_(0, "mcast_list", (uint8_t *)&val, sizeof(val), (uint8_t *)mcast_addr, sizeof(mcast_addr));
+  mg_delayms(50);
+}
+
 // CYW43 chip backplane specifics. All values read and written are in little
 // endian format
 

src/drivers/cyw.c

@@ -115,9 +115,14 @@ static bool mg_tcpip_driver_imxrt_init(struct mg_tcpip_if *ifp) {
   ENET->RDAR = MG_BIT(24);            // Receive Descriptors have changed
   ENET->TDAR = MG_BIT(24);            // Transmit Descriptors have changed
   // ENET->OPD = 0x10014;
+  ENET->IAUR = 0;
+  ENET->IALR = 0;
+  ENET->GAUR = 0;
+  ENET->GALR = 0;
   return true;
 }
 
+
 // Transmit frame
 static size_t mg_tcpip_driver_imxrt_tx(const void *buf, size_t len,
                                        struct mg_tcpip_if *ifp) {
@@ -142,7 +147,22 @@ static size_t mg_tcpip_driver_imxrt_tx(const void *buf, size_t len,
   return len;
 }
 
+static mg_tcpip_driver_imxrt_update_hash_table(struct mg_tcpip_if *ifp) {
+  // TODO(): read database, rebuild hash table
+  // RM 37.3.4.3.2
+  uint32_t hash_table[2] = {0, 0};
+  // uint8_t hash64 = ((~mg_crc32(0, mcast_addr, 6)) >> 26) & 0x3f;
+  // hash_table[((uint8_t)hash64) >> 5] |= (1 << (hash64 & 0x1f));
+  hash_table[1] = MG_BIT(1); // above reduces to this for mDNS addr
+  ENET->GAUR = hash_table[1];
+  ENET->GALR = hash_table[0];
+}
+
 static bool mg_tcpip_driver_imxrt_poll(struct mg_tcpip_if *ifp, bool s1) {
+  if (ifp->update_mac_hash_table) {
+    mg_tcpip_driver_imxrt_update_hash_table(ifp);
+    ifp->update_mac_hash_table = false;
+  }
   if (!s1) return false;
   struct mg_tcpip_driver_imxrt_data *d =
       (struct mg_tcpip_driver_imxrt_data *) ifp->driver_data;

src/drivers/imxrt.c

@@ -51,6 +51,11 @@ static bool mg_tcpip_driver_pico_w_poll(struct mg_tcpip_if *ifp, bool s1) {
     s_scanning = 0;
     mg_tcpip_call(s_ifp, MG_TCPIP_EV_WIFI_SCAN_END, NULL);
   }
+  if (ifp->update_mac_hash_table) {
+    // first call to _poll() is after _init(), so this is safe
+    cyw43_wifi_update_multicast_filter(&cyw43_state, (uint8_t *)mcast_addr, true);
+    ifp->update_mac_hash_table = false;
+  }
   if (!s1) return false;
   struct mg_tcpip_driver_pico_w_data *d =
       (struct mg_tcpip_driver_pico_w_data *) ifp->driver_data;

src/drivers/pico-w.c

@@ -101,21 +101,24 @@ static uint16_t smi_rd(uint16_t header) {
     pir = 0;  // read, mdc = 0
     ETHERC->PIR = pir;
     raspin(s_smispin / 2);  // 1/4 clock period, 300ns max access time
-    data |= (uint16_t)(ETHERC->PIR & MG_BIT(3) ? 1 : 0);  // read mdio
-    raspin(s_smispin / 2);                    // 1/4 clock period
-    pir |= MG_BIT(0);                         // mdc = 1
+    data |= (uint16_t) (ETHERC->PIR & MG_BIT(3) ? 1 : 0);  // read mdio
+    raspin(s_smispin / 2);                                 // 1/4 clock period
+    pir |= MG_BIT(0);                                      // mdc = 1
     ETHERC->PIR = pir;
     raspin(s_smispin);
   }
   return data;
 }
 
 static uint16_t raeth_read_phy(uint8_t addr, uint8_t reg) {
-  return smi_rd((uint16_t)((1 << 14) | (2 << 12) | (addr << 7) | (reg << 2) | (2 << 0)));
+  return smi_rd(
+      (uint16_t) ((1 << 14) | (2 << 12) | (addr << 7) | (reg << 2) | (2 << 0)));
 }
 
 static void raeth_write_phy(uint8_t addr, uint8_t reg, uint16_t val) {
-  smi_wr((uint16_t)((1 << 14) | (1 << 12) | (addr << 7) | (reg << 2) | (2 << 0)), val);
+  smi_wr(
+      (uint16_t) ((1 << 14) | (1 << 12) | (addr << 7) | (reg << 2) | (2 << 0)),
+      val);
 }
 
 // MDC clock is generated manually; as per 802.3, it must not exceed 2.5MHz
@@ -152,7 +155,7 @@ static bool mg_tcpip_driver_ra_init(struct mg_tcpip_if *ifp) {
 
   MG_DEBUG(("PHY addr: %d, smispin: %d", d->phy_addr, s_smispin));
   struct mg_phy phy = {raeth_read_phy, raeth_write_phy};
-  mg_phy_init(&phy, d->phy_addr, 0); // MAC clocks PHY
+  mg_phy_init(&phy, d->phy_addr, 0);  // MAC clocks PHY
 
   // Select RMII mode,
   ETHERC->ECMR = MG_BIT(2) | MG_BIT(1);  // 100M, Full-duplex, CRC
@@ -171,9 +174,9 @@ static bool mg_tcpip_driver_ra_init(struct mg_tcpip_if *ifp) {
   EDMAC->FDR = 0x070f;                    // (27.2.11)
   EDMAC->RMCR = MG_BIT(0);                // (27.2.12)
   ETHERC->ECMR |= MG_BIT(6) | MG_BIT(5);  // TE RE
-  EDMAC->EESIPR = MG_BIT(18);             // Enable Rx IRQ
-  EDMAC->EDRRR = MG_BIT(0);               // Receive Descriptors have changed
-  EDMAC->EDTRR = MG_BIT(0);               // Transmit Descriptors have changed
+  EDMAC->EESIPR = MG_BIT(18);  // FR: Enable Rx (frame) IRQ
+  EDMAC->EDRRR = MG_BIT(0);  // Receive Descriptors have changed
+  EDMAC->EDTRR = MG_BIT(0);  // Transmit Descriptors have changed
   return true;
 }
 
@@ -199,6 +202,10 @@ static size_t mg_tcpip_driver_ra_tx(const void *buf, size_t len,
 }
 
 static bool mg_tcpip_driver_ra_poll(struct mg_tcpip_if *ifp, bool s1) {
+  if (ifp->update_mac_hash_table) {
+    EDMAC->EESIPR = MG_BIT(18) | MG_BIT(7);  // FR, RMAF: Frame and mcast IRQ
+    ifp->update_mac_hash_table = false;
+  }
   if (!s1) return false;
   struct mg_tcpip_driver_ra_data *d =
       (struct mg_tcpip_driver_ra_data *) ifp->driver_data;
@@ -225,7 +232,7 @@ static uint32_t s_rxno;
 void EDMAC_IRQHandler(void) {
   struct mg_tcpip_driver_ra_data *d =
       (struct mg_tcpip_driver_ra_data *) s_ifp->driver_data;
-  EDMAC->EESR = MG_BIT(18);            // Ack IRQ in EDMAC 1st
+  EDMAC->EESR = MG_BIT(18) | MG_BIT(7);  // Ack IRQ in EDMAC 1st
   ICU_IELSR[d->irqno] &= ~MG_BIT(16);  // Ack IRQ in ICU last
   // Frame received, loop
   for (uint32_t i = 0; i < 10; i++) {  // read as they arrive but not forever