arduino-esp32/libraries/NetBIOS/src/NetBIOS.cpp at 3.1.1 · espressif/arduino-esp32 · GitHub

Name: arduino-esp32/libraries/NetBIOS/src/NetBIOS.cpp at 3.1.1 · espressif/arduino-esp32 · GitHub
Rating: 4.7 (5746 reviews)
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#include"NetBIOS.h"
#include<functional>
extern"C" {
#include<lwip/netif.h>
}; // extern "C"

#defineNBNS_PORT137
#defineNBNS_MAX_HOSTNAME_LEN32

typedefstruct {
uint16_t id;
uint8_t flags1;
uint8_t flags2;
uint16_t qcount;
uint16_t acount; // codespell:ignore acount
uint16_t nscount;
uint16_t adcount;
uint8_t name_len;
char name[NBNS_MAX_HOSTNAME_LEN + 1];
uint16_t type;
uint16_t clas;
} __attribute__((packed)) nbns_question_t;

typedefstruct {
uint16_t id;
uint8_t flags1;
uint8_t flags2;
uint16_t qcount;
uint16_t acount; // codespell:ignore acount
uint16_t nscount;
uint16_t adcount;
uint8_t name_len;
char name[NBNS_MAX_HOSTNAME_LEN + 1];
uint16_t type;
uint16_t clas;
uint32_t ttl;
uint16_t data_len;
uint16_t flags;
uint32_t addr;
} __attribute__((packed)) nbns_answer_t;

staticvoid_getnbname(constchar *nbname, char *name, uint8_t maxlen) {
uint8_t b;
uint8_t c = 0;

while ((*nbname) && (c < maxlen)) {
 b = (*nbname++ - 'A') << 4;
 c++;
if (*nbname) {
 b |= *nbname++ - 'A';
 c++;
 }
if (!b || b == '') {
break;
 }
 *name++ = b;
 }
 *name = 0;
}

staticvoidappend_16(void *dst, uint16_t value) {
uint8_t *d = (uint8_t *)dst;
 *d++ = (value >> 8) & 0xFF;
 *d++ = value & 0xFF;
}

staticvoidappend_32(void *dst, uint32_t value) {
uint8_t *d = (uint8_t *)dst;
 *d++ = (value >> 24) & 0xFF;
 *d++ = (value >> 16) & 0xFF;
 *d++ = (value >> 8) & 0xFF;
 *d++ = value & 0xFF;
}

voidNetBIOS::_onPacket(AsyncUDPPacket &packet) {
if (packet.length() >= sizeof(nbns_question_t)) {
nbns_question_t *question = (nbns_question_t *)packet.data();
if (0 == (question->flags1 & 0x80)) {
char name[NBNS_MAX_HOSTNAME_LEN + 1];
_getnbname(&question->name[0], (char *)&name, question->name_len);
if (_name.equals(name)) {
nbns_answer_t nbnsa;
 nbnsa.id = question->id;
 nbnsa.flags1 = 0x85;
 nbnsa.flags2 = 0;
append_16((void *)&nbnsa.qcount, 0);
append_16((void *)&nbnsa.acount, 1); // codespell:ignore acount
append_16((void *)&nbnsa.nscount, 0);
append_16((void *)&nbnsa.adcount, 0);
 nbnsa.name_len = question->name_len;
memcpy(&nbnsa.name[0], &question->name[0], question->name_len + 1);
append_16((void *)&nbnsa.type, 0x20);
append_16((void *)&nbnsa.clas, 1);
append_32((void *)&nbnsa.ttl, 300000);
append_16((void *)&nbnsa.data_len, 6);
append_16((void *)&nbnsa.flags, 0);
 nbnsa.addr = packet.localIP(); // By default, should be overridden below
// Iterate over all netifs, see if the incoming address matches one of the netmaskes networks
for (auto netif = netif_list; netif; netif = netif->next) {
auto maskedip = ip4_addr_get_u32(netif_ip4_addr(netif)) & ip4_addr_get_u32(netif_ip4_netmask(netif));
auto maskedin = ((uint32_t)packet.localIP()) & ip4_addr_get_u32(netif_ip4_netmask(netif));
if (maskedip == maskedin) {
 nbnsa.addr = ip4_addr_get_u32(netif_ip4_addr(netif));
break;
 }
 }
 _udp.writeTo((uint8_t *)&nbnsa, sizeof(nbnsa), packet.remoteIP(), NBNS_PORT);
 }
 }
 }
}

NetBIOS::NetBIOS() {}

NetBIOS::~NetBIOS() {
end();
}

boolNetBIOS::begin(constchar *name) {
 _name = name;
 _name.toUpperCase();

if (_udp.connected()) {
returntrue;
 }

 _udp.onPacket(
 [](void *arg, AsyncUDPPacket &packet) {
 ((NetBIOS *)(arg))->_onPacket(packet);
 },
this
 );
return _udp.listen(NBNS_PORT);
}

voidNetBIOS::end() {
if (_udp.connected()) {
 _udp.close();
 }
}

#if !defined(NO_GLOBAL_INSTANCES) && !defined(NO_GLOBAL_NETBIOS)
NetBIOS NBNS;
#endif

// EOF