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Merged
merged 1 commit into from
Aug 1, 2025
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Built-in TCP/IP (re-)starts DNS connection on DHCP link up #3203

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50 changes: 37 additions & 13 deletions mongoose.c
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Original file line number Diff line number Diff line change
Expand Up @@ -353,19 +353,24 @@ static bool mg_dns_send(struct mg_connection *c, const struct mg_str *name,
return mg_send(c, &pkt, sizeof(pkt.header) + n);
}

static void mg_sendnsreq(struct mg_connection *c, struct mg_str *name, int ms,
struct mg_dns *dnsc, bool ipv6) {
struct dns_data *d = NULL;
bool mg_dnsc_init(struct mg_mgr *mgr, struct mg_dns *dnsc);
bool mg_dnsc_init(struct mg_mgr *mgr, struct mg_dns *dnsc) {
if (dnsc->url == NULL) {
mg_error(c, "DNS server URL is NULL. Call mg_mgr_init()");
} else if (dnsc->c == NULL) {
dnsc->c = mg_connect(c->mgr, dnsc->url, NULL, NULL);
if (dnsc->c != NULL) {
dnsc->c->pfn = dns_cb;
// dnsc->c->is_hexdumping = 1;
}
mg_error(0, "DNS server URL is NULL. Call mg_mgr_init()");
return false;
}
if (dnsc->c == NULL) {
dnsc->c = mg_connect(mgr, dnsc->url, NULL, NULL);
if (dnsc->c == NULL) return false;
dnsc->c->pfn = dns_cb;
}
return true;
}

static void mg_sendnsreq(struct mg_connection *c, struct mg_str *name, int ms,
struct mg_dns *dnsc, bool ipv6) {
struct dns_data *d = NULL;
if (!mg_dnsc_init(c->mgr, dnsc)) {
mg_error(c, "resolver");
} else if ((d = (struct dns_data *) mg_calloc(1, sizeof(*d))) == NULL) {
mg_error(c, "resolve OOM");
Expand Down Expand Up @@ -467,6 +472,7 @@ struct mg_connection *mg_mdns_listen(struct mg_mgr *mgr, char *name) {
return c;
}


#ifdef MG_ENABLE_LINES
#line 1 "src/event.c"
#endif
Expand Down Expand Up @@ -4577,6 +4583,8 @@ static void rx_icmp(struct mg_tcpip_if *ifp, struct pkt *pkt) {
}
}

static void setdns4(struct mg_tcpip_if *ifp, uint32_t *ip);

static void rx_dhcp_client(struct mg_tcpip_if *ifp, struct pkt *pkt) {
uint32_t ip = 0, gw = 0, mask = 0, lease = 0, dns = 0, sntp = 0;
uint8_t msgtype = 0, state = ifp->state;
Expand Down Expand Up @@ -4625,8 +4633,10 @@ static void rx_dhcp_client(struct mg_tcpip_if *ifp, struct pkt *pkt) {
ifp->state = MG_TCPIP_STATE_IP; // BOUND state
mg_random(&rand, sizeof(rand));
srand((unsigned int) (rand + mg_millis()));
if (ifp->enable_req_dns && dns != 0)
if (ifp->enable_req_dns && dns != 0) {
setdns4(ifp, &dns);
mg_tcpip_call(ifp, MG_TCPIP_EV_DHCP_DNS, &dns);
}
if (ifp->enable_req_sntp && sntp != 0)
mg_tcpip_call(ifp, MG_TCPIP_EV_DHCP_SNTP, &sntp);
} else if (ifp->state == MG_TCPIP_STATE_READY && ifp->ip == ip) { // renew
Expand Down Expand Up @@ -5287,6 +5297,7 @@ void mg_tcpip_init(struct mg_mgr *mgr, struct mg_tcpip_if *ifp) {
void mg_tcpip_free(struct mg_tcpip_if *ifp) {
mg_free(ifp->recv_queue.buf);
mg_free(ifp->tx.buf);
mg_free(ifp->dns4_url);
}

static void send_syn(struct mg_connection *c) {
Expand Down Expand Up @@ -5453,6 +5464,21 @@ void mg_multicast_add(struct mg_connection *c, char *ip) {
c->mgr->ifp->update_mac_hash_table = true; // mark dirty
}

bool mg_dnsc_init(struct mg_mgr *mgr, struct mg_dns *dnsc);

static void setdns4(struct mg_tcpip_if *ifp, uint32_t *ip) {
struct mg_dns *dnsc;
mg_free(ifp->dns4_url);
ifp->dns4_url = mg_mprintf("udp://%M:53", mg_print_ip4, ip);
dnsc = &ifp->mgr->dns4;
dnsc->url = (const char *) ifp->dns4_url;
MG_DEBUG(("Set DNS URL to %s", dnsc->url));
if (ifp->mgr->use_dns6) return;
if (dnsc->c != NULL) mg_close_conn(dnsc->c);
if (!mg_dnsc_init(ifp->mgr, dnsc)) // create DNS connection
MG_ERROR(("DNS connection creation failed"));
}

#endif // MG_ENABLE_TCPIP

#ifdef MG_ENABLE_LINES
Expand Down Expand Up @@ -8600,10 +8626,8 @@ int64_t mg_sntp_parse(const unsigned char *buf, size_t len) {
static void sntp_cb(struct mg_connection *c, int ev, void *ev_data) {
uint64_t *expiration_time = (uint64_t *) c->data;
if (ev == MG_EV_OPEN) {
MG_INFO(("%lu PFN OPEN", c->id));
*expiration_time = mg_millis() + 3000; // Store expiration time in 3s
} else if (ev == MG_EV_CONNECT) {
MG_INFO(("%lu PFN CONNECT, sending request", c->id));
mg_sntp_request(c);
} else if (ev == MG_EV_READ) {
int64_t milliseconds = mg_sntp_parse(c->recv.buf, c->recv.len);
Expand Down
1 change: 1 addition & 0 deletions mongoose.h
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Original file line number Diff line number Diff line change
Expand Up @@ -3003,6 +3003,7 @@ struct mg_tcpip_if {

// Internal state, user can use it but should not change it
uint8_t gwmac[6]; // Router's MAC
char *dns4_url; // DNS server URL
uint64_t now; // Current time
uint64_t timer_1000ms; // 1000 ms timer: for DHCP and link state
uint64_t lease_expire; // Lease expiration time, in ms
Expand Down
26 changes: 16 additions & 10 deletions src/dns.c
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Original file line number Diff line number Diff line change
Expand Up @@ -232,19 +232,24 @@ static bool mg_dns_send(struct mg_connection *c, const struct mg_str *name,
return mg_send(c, &pkt, sizeof(pkt.header) + n);
}

static void mg_sendnsreq(struct mg_connection *c, struct mg_str *name, int ms,
struct mg_dns *dnsc, bool ipv6) {
struct dns_data *d = NULL;
bool mg_dnsc_init(struct mg_mgr *mgr, struct mg_dns *dnsc);
bool mg_dnsc_init(struct mg_mgr *mgr, struct mg_dns *dnsc) {
if (dnsc->url == NULL) {
mg_error(c, "DNS server URL is NULL. Call mg_mgr_init()");
} else if (dnsc->c == NULL) {
dnsc->c = mg_connect(c->mgr, dnsc->url, NULL, NULL);
if (dnsc->c != NULL) {
dnsc->c->pfn = dns_cb;
// dnsc->c->is_hexdumping = 1;
}
mg_error(0, "DNS server URL is NULL. Call mg_mgr_init()");
return false;
}
if (dnsc->c == NULL) {
dnsc->c = mg_connect(mgr, dnsc->url, NULL, NULL);
if (dnsc->c == NULL) return false;
dnsc->c->pfn = dns_cb;
}
return true;
}

static void mg_sendnsreq(struct mg_connection *c, struct mg_str *name, int ms,
struct mg_dns *dnsc, bool ipv6) {
struct dns_data *d = NULL;
if (!mg_dnsc_init(c->mgr, dnsc)) {
mg_error(c, "resolver");
} else if ((d = (struct dns_data *) mg_calloc(1, sizeof(*d))) == NULL) {
mg_error(c, "resolve OOM");
Expand Down Expand Up @@ -345,3 +350,4 @@ struct mg_connection *mg_mdns_listen(struct mg_mgr *mgr, char *name) {
if (c != NULL) mg_multicast_add(c, (char *)"224.0.0.251");
return c;
}

22 changes: 21 additions & 1 deletion src/net_builtin.c
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Original file line number Diff line number Diff line change
Expand Up @@ -407,6 +407,8 @@ static void rx_icmp(struct mg_tcpip_if *ifp, struct pkt *pkt) {
}
}

static void setdns4(struct mg_tcpip_if *ifp, uint32_t *ip);

static void rx_dhcp_client(struct mg_tcpip_if *ifp, struct pkt *pkt) {
uint32_t ip = 0, gw = 0, mask = 0, lease = 0, dns = 0, sntp = 0;
uint8_t msgtype = 0, state = ifp->state;
Expand Down Expand Up @@ -455,8 +457,10 @@ static void rx_dhcp_client(struct mg_tcpip_if *ifp, struct pkt *pkt) {
ifp->state = MG_TCPIP_STATE_IP; // BOUND state
mg_random(&rand, sizeof(rand));
srand((unsigned int) (rand + mg_millis()));
if (ifp->enable_req_dns && dns != 0)
if (ifp->enable_req_dns && dns != 0) {
setdns4(ifp, &dns);
mg_tcpip_call(ifp, MG_TCPIP_EV_DHCP_DNS, &dns);
}
if (ifp->enable_req_sntp && sntp != 0)
mg_tcpip_call(ifp, MG_TCPIP_EV_DHCP_SNTP, &sntp);
} else if (ifp->state == MG_TCPIP_STATE_READY && ifp->ip == ip) { // renew
Expand Down Expand Up @@ -1117,6 +1121,7 @@ void mg_tcpip_init(struct mg_mgr *mgr, struct mg_tcpip_if *ifp) {
void mg_tcpip_free(struct mg_tcpip_if *ifp) {
mg_free(ifp->recv_queue.buf);
mg_free(ifp->tx.buf);
mg_free(ifp->dns4_url);
}

static void send_syn(struct mg_connection *c) {
Expand Down Expand Up @@ -1283,4 +1288,19 @@ void mg_multicast_add(struct mg_connection *c, char *ip) {
c->mgr->ifp->update_mac_hash_table = true; // mark dirty
}

bool mg_dnsc_init(struct mg_mgr *mgr, struct mg_dns *dnsc);

static void setdns4(struct mg_tcpip_if *ifp, uint32_t *ip) {
struct mg_dns *dnsc;
mg_free(ifp->dns4_url);
ifp->dns4_url = mg_mprintf("udp://%M:53", mg_print_ip4, ip);
dnsc = &ifp->mgr->dns4;
dnsc->url = (const char *) ifp->dns4_url;
MG_DEBUG(("Set DNS URL to %s", dnsc->url));
if (ifp->mgr->use_dns6) return;
if (dnsc->c != NULL) mg_close_conn(dnsc->c);
if (!mg_dnsc_init(ifp->mgr, dnsc)) // create DNS connection
MG_ERROR(("DNS connection creation failed"));
}

#endif // MG_ENABLE_TCPIP
1 change: 1 addition & 0 deletions src/net_builtin.h
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Original file line number Diff line number Diff line change
Expand Up @@ -57,6 +57,7 @@ struct mg_tcpip_if {

// Internal state, user can use it but should not change it
uint8_t gwmac[6]; // Router's MAC
char *dns4_url; // DNS server URL
uint64_t now; // Current time
uint64_t timer_1000ms; // 1000 ms timer: for DHCP and link state
uint64_t lease_expire; // Lease expiration time, in ms
Expand Down
12 changes: 5 additions & 7 deletions tutorials/tcpip/tap-driver/main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -42,21 +42,20 @@ static size_t tap_rx(void *buf, size_t len, struct mg_tcpip_if *ifp) {
return (size_t) received;
}

char *s_dns = NULL, *s_sntp = NULL;
char *s_sntp = NULL;

static void mif_fn(struct mg_tcpip_if *ifp, int ev, void *ev_data) {
if (ev == MG_TCPIP_EV_ST_CHG) {
MG_INFO(("State change: %u", *(uint8_t *) ev_data));
} else if (ev == MG_TCPIP_EV_DHCP_DNS) {
mg_free(s_dns);
s_dns = mg_mprintf("udp://%M:53", mg_print_ip4, (uint32_t *) ev_data);
ifp->mgr->dns4.url = s_dns;
MG_INFO(("Set DNS to %s", ifp->mgr->dns4.url));
MG_INFO(("Got DNS from DHCP: %M", mg_print_ip4, (uint32_t *) ev_data));
} else if (ev == MG_TCPIP_EV_DHCP_SNTP) {
MG_INFO(("Got SNTP from DHCP: %M", mg_print_ip4, (uint32_t *) ev_data));
mg_free(s_sntp);
s_sntp = mg_mprintf("udp://%M:123", mg_print_ip4, (uint32_t *) ev_data);
MG_INFO(("Set SNTP to %s", s_sntp));
MG_INFO(("Set SNTP server to %s", s_sntp)); // though net.c may not use it.
}
(void) ifp;
}

int main(int argc, char *argv[]) {
Expand Down Expand Up @@ -128,7 +127,6 @@ int main(int argc, char *argv[]) {
web_init(&mgr);
while (s_signo == 0) mg_mgr_poll(&mgr, 100); // Infinite event loop

mg_free(s_dns);
mg_free(s_sntp);
mg_mgr_free(&mgr);
close(fd);
Expand Down
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