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Merge pull request #3353 from cesanta/safety-net

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Add safety nets for lousy networks
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Sergey Lyubka authored and GitHub committed 2025-12-03 15:49:41 +00:00
2 parents 0f1a3cf84b 66dcca9392
commit b3d27a3c43
5 files changed
+182 -46
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mongoose.c
+88 -23
View File
@@ -4872,6 +4872,8 @@ static struct mg_connection *getpeer(struct mg_mgr *mgr, struct pkt *pkt,
}
static void mac_resolved(struct mg_connection *c);
static uint8_t *get_return_mac(struct mg_tcpip_if *ifp, struct mg_addr *rem,
bool is_udp, struct pkt *pkt);
static void rx_arp(struct mg_tcpip_if *ifp, struct pkt *pkt) {
if (pkt->arp->op == mg_htons(1) && pkt->arp->tpa == ifp->ip) {
@@ -4897,6 +4899,7 @@ static void rx_arp(struct mg_tcpip_if *ifp, struct pkt *pkt) {
if (pkt->arp->spa == ifp->gw) {
// Got response for the GW ARP request. Set ifp->gwmac and IP -> READY
memcpy(ifp->gwmac, pkt->arp->sha, sizeof(ifp->gwmac));
ifp->gw_ready = true;
if (ifp->state == MG_TCPIP_STATE_IP) {
ifp->state = MG_TCPIP_STATE_READY;
onstatechange(ifp);
@@ -4921,6 +4924,11 @@ static void rx_icmp(struct mg_tcpip_if *ifp, struct pkt *pkt) {
size_t space = ifp->tx.len - hlen, plen = pkt->pay.len;
struct ip *ip;
struct icmp *icmp;
struct mg_addr ips;
ips.ip4 = pkt->ip->src;
ips.is_ip6 = false;
if (get_return_mac(ifp, &ips, false, pkt) == NULL)
return; // safety net for lousy networks
if (plen > space) plen = space;
ip = tx_ip(ifp, pkt->eth->src, 1, ifp->ip, pkt->ip->src,
sizeof(*icmp) + plen);
@@ -4940,7 +4948,7 @@ static void rx_dhcp_client(struct mg_tcpip_if *ifp, struct pkt *pkt) {
// perform size check first, then access fields
uint8_t *p = pkt->dhcp->options,
*end = (uint8_t *) &pkt->pay.buf[pkt->pay.len];
if (end < p) return; // options are optional, check min header length
if (end < p) return; // options are optional, check min header length
if (memcmp(&pkt->dhcp->xid, ifp->mac + 2, sizeof(pkt->dhcp->xid))) return;
while (p + 1 < end && p[0] != 255) { // Parse options RFC-1533 #9
if (p[0] == 1 && p[1] == sizeof(ifp->mask) && p + 6 < end) { // Mask
@@ -4978,6 +4986,7 @@ static void rx_dhcp_client(struct mg_tcpip_if *ifp, struct pkt *pkt) {
MG_INFO(("Lease: %u sec (%lld)", lease, ifp->lease_expire / 1000));
// assume DHCP server = router until ARP resolves
memcpy(ifp->gwmac, pkt->eth->src, sizeof(ifp->gwmac));
ifp->gw_ready = true; // NOTE(): actual gw ARP won't retry now
ifp->ip = ip, ifp->gw = gw, ifp->mask = mask;
ifp->state = MG_TCPIP_STATE_IP; // BOUND state
mg_random(&rand, sizeof(rand));
@@ -5002,7 +5011,7 @@ static void rx_dhcp_server(struct mg_tcpip_if *ifp, struct pkt *pkt) {
*end = (uint8_t *) &pkt->pay.buf[pkt->pay.len];
// struct dhcp *req = pkt->dhcp;
struct dhcp res = {2, 1, 6, 0, 0, 0, 0, 0, 0, 0, 0, {0}, 0, {0}};
if (end < p) return; // options are optional, check min header length
if (end < p) return; // options are optional, check min header length
res.yiaddr = ifp->ip;
((uint8_t *) (&res.yiaddr))[3]++; // Offer our IP + 1
while (p + 1 < end && p[0] != 255) { // Parse options
@@ -5106,6 +5115,7 @@ static void rx_ndp_na(struct mg_tcpip_if *ifp, struct pkt *pkt) {
if (MG_IP6MATCH(na->addr, ifp->gw6)) {
// Got response for the GW NS request. Set ifp->gw6mac and IP6 -> READY
memcpy(ifp->gw6mac, opts, sizeof(ifp->gw6mac));
ifp->gw6_ready = true;
if (ifp->state6 == MG_TCPIP_STATE_IP) {
ifp->state6 = MG_TCPIP_STATE_READY;
onstate6change(ifp);
@@ -5226,6 +5236,7 @@ static void rx_ndp_ra(struct mg_tcpip_if *ifp, struct pkt *pkt) {
// Received router's MAC address
ifp->state6 = MG_TCPIP_STATE_READY;
memcpy(ifp->gw6mac, opts + 2, 6);
ifp->gw6_ready = true;
} else if (type == 5 && length >= 8) {
// process MTU if available
uint32_t mtu = mg_ntohl(*(uint32_t *) (opts + 4));
@@ -5272,6 +5283,11 @@ static void rx_icmp6(struct mg_tcpip_if *ifp, struct pkt *pkt) {
size_t hlen =
sizeof(struct eth) + sizeof(struct ip6) + sizeof(struct icmp6);
size_t space = ifp->tx.len - hlen, plen = pkt->pay.len;
struct mg_addr ips;
ips.ip6[0] = pkt->ip6->src[0], ips.ip6[1] = pkt->ip6->src[1];
ips.is_ip6 = true;
if (get_return_mac(ifp, &ips, false, pkt) == NULL)
return; // safety net for lousy networks
if (plen > space) plen = space; // Copy (truncated) RX payload to TX
// Echo Reply, 4.2
tx_icmp6(ifp, pkt->eth->src, pkt->ip6->dst, pkt->ip6->src, 129, 0,
@@ -5296,7 +5312,7 @@ static void onstate6change(struct mg_tcpip_if *ifp) {
MG_INFO((" GW: %M", mg_print_ip6, &ifp->gw6));
MG_INFO((" MAC: %M", mg_print_mac, &ifp->mac));
} else if (ifp->state6 == MG_TCPIP_STATE_IP) {
if (ifp->gw6[0] != 0 || ifp->gw6[1] != 0)
if (ifp->gw6[0] != 0 || ifp->gw6[1] != 0)
tx_ndp_ns(ifp, ifp->gw6, ifp->gw6mac); // unsolicited GW MAC resolution
} else if (ifp->state6 == MG_TCPIP_STATE_UP) {
MG_INFO(("IP: %M", mg_print_ip6, &ifp->ip6ll));
@@ -5306,9 +5322,43 @@ static void onstate6change(struct mg_tcpip_if *ifp) {
}
#endif
static uint8_t *get_return_mac(struct mg_tcpip_if *ifp, struct mg_addr *rem,
bool is_udp, struct pkt *pkt) {
#if MG_ENABLE_IPV6
if (rem->is_ip6) {
if (is_udp && MG_IP6MATCH(rem->ip6, ip6_allnodes.u)) // local broadcast
return (uint8_t *) ip6mac_allnodes;
if (rem->ip6[0] == ifp->ip6[0]) // TODO(): HANDLE PREFIX ***
return pkt->eth->src; // we're on the same LAN, get MAC from frame
if (is_udp && *((uint8_t *) rem->ip6) == 0xFF) // multicast
{
} // TODO(): ip6_mcastmac(s->mac, c->rem.ip6), l2 PR handles this better
if (ifp->gw6_ready) // use the router
return ifp->gw6mac; // ignore source MAC in frame
} else
#endif
{
uint32_t rem_ip = rem->ip4;
if (is_udp && (rem_ip == 0xffffffff || rem_ip == (ifp->ip | ~ifp->mask)))
return (uint8_t *) broadcast; // global or local broadcast
if (ifp->ip != 0 && ((rem_ip & ifp->mask) == (ifp->ip & ifp->mask)))
return pkt->eth->src; // we're on the same LAN, get MAC from frame
if (is_udp &&
(*((uint8_t *) &rem_ip) & 0xE0) == 0xE0) // 224 to 239, E0 to EF
{
} // TODO(): ip4_mcastmac(s->mac, &rem_ip); // multicast group, l2 PR
if (ifp->gw_ready) // use the router, ignore source MAC
return ifp->gwmac;
}
MG_ERROR(("%M %s: No way back, can't respond", mg_print_ip_port, rem,
is_udp ? "UDP" : "TCP"));
return NULL;
}
static bool rx_udp(struct mg_tcpip_if *ifp, struct pkt *pkt) {
struct mg_connection *c = getpeer(ifp->mgr, pkt, true);
struct connstate *s;
uint8_t *mac;
if (c == NULL) return false; // No UDP listener on this port
s = (struct connstate *) (c + 1);
c->rem.port = pkt->udp->sport;
@@ -5321,7 +5371,9 @@ static bool rx_udp(struct mg_tcpip_if *ifp, struct pkt *pkt) {
{
c->rem.ip4 = pkt->ip->src;
}
memcpy(s->mac, pkt->eth->src, sizeof(s->mac));
if ((mac = get_return_mac(ifp, &c->rem, true, pkt)) == NULL)
return false; // safety net for lousy networks
memcpy(s->mac, mac, sizeof(s->mac));
if (c->recv.len >= MG_MAX_RECV_SIZE) {
mg_error(c, "max_recv_buf_size reached");
} else if (c->recv.size - c->recv.len < pkt->pay.len &&
@@ -5410,6 +5462,7 @@ static size_t tx_tcp_ctrlresp(struct mg_tcpip_if *ifp, struct pkt *pkt,
uint32_t ackno = mg_htonl(mg_ntohl(pkt->tcp->seq) + (uint32_t) pkt->pay.len +
((pkt->tcp->flags & (TH_SYN | TH_FIN)) ? 1 : 0));
struct mg_addr ips, ipd;
uint8_t *mac;
memset(&ips, 0, sizeof(ips));
memset(&ipd, 0, sizeof(ipd));
if (pkt->ip != NULL) {
@@ -5423,7 +5476,9 @@ static size_t tx_tcp_ctrlresp(struct mg_tcpip_if *ifp, struct pkt *pkt,
}
ips.port = pkt->tcp->dport;
ipd.port = pkt->tcp->sport;
return tx_tcp(ifp, pkt->eth->src, &ips, &ipd, flags, seqno, ackno, NULL, 0);
if ((mac = get_return_mac(ifp, &ipd, false, pkt)) == NULL)
return 0; // safety net for lousy networks
return tx_tcp(ifp, mac, &ips, &ipd, flags, seqno, ackno, NULL, 0);
}
static size_t tx_tcp_rst(struct mg_tcpip_if *ifp, struct pkt *pkt, bool toack) {
@@ -5435,6 +5490,7 @@ static struct mg_connection *accept_conn(struct mg_connection *lsn,
struct pkt *pkt, uint16_t mss) {
struct mg_connection *c = mg_alloc_conn(lsn->mgr);
struct connstate *s;
uint8_t *mac;
if (c == NULL) {
MG_ERROR(("OOM"));
return NULL;
@@ -5442,8 +5498,6 @@ static struct mg_connection *accept_conn(struct mg_connection *lsn,
s = (struct connstate *) (c + 1);
s->dmss = mss; // from options in client SYN
s->seq = mg_ntohl(pkt->tcp->ack), s->ack = mg_ntohl(pkt->tcp->seq);
memcpy(s->mac, pkt->eth->src, sizeof(s->mac));
settmout(c, MIP_TTYPE_KEEPALIVE);
#if MG_ENABLE_IPV6
if (lsn->loc.is_ip6) {
c->rem.ip6[0] = pkt->ip6->src[0], c->rem.ip6[1] = pkt->ip6->src[1],
@@ -5459,6 +5513,12 @@ static struct mg_connection *accept_conn(struct mg_connection *lsn,
}
c->rem.port = pkt->tcp->sport;
c->loc.port = lsn->loc.port;
if ((mac = get_return_mac(lsn->mgr->ifp, &c->rem, false, pkt)) == NULL) {
free(c); // safety net for lousy networks, not actually needed
return NULL; // as path has already been checked at SYN (sending SYN+ACK)
}
memcpy(s->mac, mac, sizeof(s->mac));
settmout(c, MIP_TTYPE_KEEPALIVE);
MG_DEBUG(("%lu accepted %M", c->id, mg_print_ip_port, &c->rem));
LIST_ADD_HEAD(struct mg_connection, &lsn->mgr->conns, c);
c->is_accepted = 1;
@@ -5770,7 +5830,8 @@ static void rx_tcp(struct mg_tcpip_if *ifp, struct pkt *pkt) {
// Use peer's src port and bl key as ISN, to later identify the
// handshake
isn = (mg_htonl(((uint32_t) key << 16) | mg_ntohs(pkt->tcp->sport)));
tx_tcp_ctrlresp(ifp, pkt, TH_SYN | TH_ACK, isn);
if (tx_tcp_ctrlresp(ifp, pkt, TH_SYN | TH_ACK, isn) == 0)
backlog_remove(c, (uint16_t) key); // safety net for lousy networks
} // what should we do when port=0 ? Linux takes port 0 as any other
// port
} else if (pkt->tcp->flags == TH_ACK) {
@@ -5804,10 +5865,10 @@ static void rx_ip(struct mg_tcpip_if *ifp, struct pkt *pkt) {
if (ihl < 5) return; // bad IHL
if (pkt->pay.len < (uint16_t) (ihl * 4)) return; // Truncated / malformed
// There can be link padding, take length from IP header
len = mg_ntohs(pkt->ip->len); // IP datagram length
len = mg_ntohs(pkt->ip->len); // IP datagram length
if (len < (uint16_t) (ihl * 4) || len > pkt->pay.len) return; // malformed
pkt->pay.len = len; // strip padding
mkpay(pkt, (uint32_t *) pkt->ip + ihl); // account for opts
pkt->pay.len = len; // strip padding
mkpay(pkt, (uint32_t *) pkt->ip + ihl); // account for opts
frag = mg_ntohs(pkt->ip->frag);
if (frag & IP_MORE_FRAGS_MSK || frag & IP_FRAG_OFFSET_MSK) {
struct mg_connection *c;
@@ -6074,15 +6135,21 @@ static void mg_tcpip_poll(struct mg_tcpip_if *ifp, uint64_t now) {
}
// Handle gw ARP request timeout, order is important
if (expired_1000ms && ifp->state == MG_TCPIP_STATE_IP) {
ifp->state = MG_TCPIP_STATE_READY; // keep best-effort MAC
ifp->state = MG_TCPIP_STATE_READY; // keep best-effort MAC or poison mark
onstatechange(ifp);
}
if (expired_1000ms && ifp->state == MG_TCPIP_STATE_READY && !ifp->gw_ready &&
ifp->gw != 0)
mg_tcpip_arp_request(ifp, ifp->gw, NULL); // retry GW ARP request
#if MG_ENABLE_IPV6
// Handle gw NS/NA req/resp timeout, order is important
if (expired_1000ms && ifp->state6 == MG_TCPIP_STATE_IP) {
ifp->state6 = MG_TCPIP_STATE_READY; // keep best-effort MAC
ifp->state6 = MG_TCPIP_STATE_READY; // keep best-effort MAC or poison mark
onstate6change(ifp);
}
if (expired_1000ms && ifp->state == MG_TCPIP_STATE_READY && !ifp->gw6_ready &&
(ifp->gw6[0] != 0 || ifp->gw6[1] != 0))
tx_ndp_ns(ifp, ifp->gw6, ifp->gw6mac); // retry GW MAC resolution
#endif
// poll driver
@@ -6196,9 +6263,8 @@ void mg_tcpip_init(struct mg_mgr *mgr, struct mg_tcpip_if *ifp) {
ifp->mtu = MG_TCPIP_MTU_DEFAULT;
mgr->extraconnsize = sizeof(struct connstate);
if (ifp->ip == 0) ifp->enable_dhcp_client = true;
memset(ifp->gwmac, 255, sizeof(ifp->gwmac)); // Set best-effort to bcast
mg_random(&ifp->eport, sizeof(ifp->eport)); // Random from 0 to 65535
ifp->eport |= MG_EPHEMERAL_PORT_BASE; // Random from
mg_random(&ifp->eport, sizeof(ifp->eport)); // Random from 0 to 65535
ifp->eport |= MG_EPHEMERAL_PORT_BASE; // Random from
// MG_EPHEMERAL_PORT_BASE to 65535
if (ifp->tx.buf == NULL || ifp->recv_queue.buf == NULL) MG_ERROR(("OOM"));
#if MG_ENABLE_IPV6
@@ -6208,7 +6274,6 @@ void mg_tcpip_init(struct mg_mgr *mgr, struct mg_tcpip_if *ifp) {
ifp->enable_slaac = true;
ip6genll((uint8_t *) ifp->ip6ll, ifp->mac); // build link-local address
}
memset(ifp->gw6mac, 255, sizeof(ifp->gw6mac)); // Set best-effort to bcast
#endif
}
}
@@ -6267,7 +6332,7 @@ void mg_connect_resolved(struct mg_connection *c) {
struct connstate *s = (struct connstate *) (c + 1);
memcpy(s->mac, ip6mac_allnodes, sizeof(s->mac));
mac_resolved(c);
} else if (c->rem.ip6[0] == ifp->ip6[0] &&
} else if (c->rem.ip6[0] == ifp->ip6[0] && // TODO(): HANDLE PREFIX ***
!MG_IP6MATCH(c->rem.ip6,
ifp->gw6)) { // skip if gw (onstate6change -> NS)
// If we're in the same LAN, fire a Neighbor Solicitation
@@ -6275,11 +6340,11 @@ void mg_connect_resolved(struct mg_connection *c) {
tx_ndp_ns(ifp, c->rem.ip6, ifp->mac);
settmout(c, MIP_TTYPE_ARP);
c->is_arplooking = 1;
} else if (*((uint8_t *) c->rem.ip6) == 0xFF) { // multicast
} else if (c->is_udp && *((uint8_t *) c->rem.ip6) == 0xFF) { // multicast
struct connstate *s = (struct connstate *) (c + 1);
ip6_mcastmac(s->mac, c->rem.ip6);
mac_resolved(c);
} else if (ifp->gw6[0] != 0 || ifp->gw6[1] != 0) {
} else if (ifp->gw6_ready) {
struct connstate *s = (struct connstate *) (c + 1);
memcpy(s->mac, ifp->gw6mac, sizeof(s->mac));
mac_resolved(c);
@@ -6302,14 +6367,14 @@ void mg_connect_resolved(struct mg_connection *c) {
mg_tcpip_arp_request(ifp, rem_ip, NULL);
settmout(c, MIP_TTYPE_ARP);
c->is_arplooking = 1;
} else if ((*((uint8_t *) &rem_ip) & 0xE0) == 0xE0) {
} else if (c->is_udp && (*((uint8_t *) &rem_ip) & 0xE0) == 0xE0) {
struct connstate *s =
(struct connstate *) (c + 1); // 224 to 239, E0 to EF
ip4_mcastmac(s->mac, &rem_ip); // multicast group
mac_resolved(c);
} else if (ifp->gw != 0) {
} else if (ifp->gw_ready) {
struct connstate *s = (struct connstate *) (c + 1);
memcpy(s->mac, ifp->gwmac, sizeof(ifp->gwmac));
memcpy(s->mac, ifp->gwmac, sizeof(s->mac));
mac_resolved(c);
} else {
MG_ERROR(("No gateway, can't connect"));
mongoose.h
+2
View File
@@ -3219,9 +3219,11 @@ struct mg_tcpip_if {
#define MG_TCPIP_STATE_REQ 2 // Interface is up, DHCP REQUESTING state
#define MG_TCPIP_STATE_IP 3 // Interface is up and has an IP assigned
#define MG_TCPIP_STATE_READY 4 // Interface has fully come up, ready to work
bool gw_ready; // We've got a hw address for the router
#if MG_ENABLE_IPV6
uint8_t gw6mac[6]; // IPv6 Router's MAC
uint8_t state6; // Current IPv6 state
bool gw6_ready; // We've got a hw address for the IPv6 router
#endif
};
void mg_tcpip_init(struct mg_mgr *, struct mg_tcpip_if *);
src/net_builtin.c
+88 -23
View File
@@ -489,6 +489,8 @@ static struct mg_connection *getpeer(struct mg_mgr *mgr, struct pkt *pkt,
}
static void mac_resolved(struct mg_connection *c);
static uint8_t *get_return_mac(struct mg_tcpip_if *ifp, struct mg_addr *rem,
bool is_udp, struct pkt *pkt);
static void rx_arp(struct mg_tcpip_if *ifp, struct pkt *pkt) {
if (pkt->arp->op == mg_htons(1) && pkt->arp->tpa == ifp->ip) {
@@ -514,6 +516,7 @@ static void rx_arp(struct mg_tcpip_if *ifp, struct pkt *pkt) {
if (pkt->arp->spa == ifp->gw) {
// Got response for the GW ARP request. Set ifp->gwmac and IP -> READY
memcpy(ifp->gwmac, pkt->arp->sha, sizeof(ifp->gwmac));
ifp->gw_ready = true;
if (ifp->state == MG_TCPIP_STATE_IP) {
ifp->state = MG_TCPIP_STATE_READY;
onstatechange(ifp);
@@ -538,6 +541,11 @@ static void rx_icmp(struct mg_tcpip_if *ifp, struct pkt *pkt) {
size_t space = ifp->tx.len - hlen, plen = pkt->pay.len;
struct ip *ip;
struct icmp *icmp;
struct mg_addr ips;
ips.ip4 = pkt->ip->src;
ips.is_ip6 = false;
if (get_return_mac(ifp, &ips, false, pkt) == NULL)
return; // safety net for lousy networks
if (plen > space) plen = space;
ip = tx_ip(ifp, pkt->eth->src, 1, ifp->ip, pkt->ip->src,
sizeof(*icmp) + plen);
@@ -557,7 +565,7 @@ static void rx_dhcp_client(struct mg_tcpip_if *ifp, struct pkt *pkt) {
// perform size check first, then access fields
uint8_t *p = pkt->dhcp->options,
*end = (uint8_t *) &pkt->pay.buf[pkt->pay.len];
if (end < p) return; // options are optional, check min header length
if (end < p) return; // options are optional, check min header length
if (memcmp(&pkt->dhcp->xid, ifp->mac + 2, sizeof(pkt->dhcp->xid))) return;
while (p + 1 < end && p[0] != 255) { // Parse options RFC-1533 #9
if (p[0] == 1 && p[1] == sizeof(ifp->mask) && p + 6 < end) { // Mask
@@ -595,6 +603,7 @@ static void rx_dhcp_client(struct mg_tcpip_if *ifp, struct pkt *pkt) {
MG_INFO(("Lease: %u sec (%lld)", lease, ifp->lease_expire / 1000));
// assume DHCP server = router until ARP resolves
memcpy(ifp->gwmac, pkt->eth->src, sizeof(ifp->gwmac));
ifp->gw_ready = true; // NOTE(): actual gw ARP won't retry now
ifp->ip = ip, ifp->gw = gw, ifp->mask = mask;
ifp->state = MG_TCPIP_STATE_IP; // BOUND state
mg_random(&rand, sizeof(rand));
@@ -619,7 +628,7 @@ static void rx_dhcp_server(struct mg_tcpip_if *ifp, struct pkt *pkt) {
*end = (uint8_t *) &pkt->pay.buf[pkt->pay.len];
// struct dhcp *req = pkt->dhcp;
struct dhcp res = {2, 1, 6, 0, 0, 0, 0, 0, 0, 0, 0, {0}, 0, {0}};
if (end < p) return; // options are optional, check min header length
if (end < p) return; // options are optional, check min header length
res.yiaddr = ifp->ip;
((uint8_t *) (&res.yiaddr))[3]++; // Offer our IP + 1
while (p + 1 < end && p[0] != 255) { // Parse options
@@ -723,6 +732,7 @@ static void rx_ndp_na(struct mg_tcpip_if *ifp, struct pkt *pkt) {
if (MG_IP6MATCH(na->addr, ifp->gw6)) {
// Got response for the GW NS request. Set ifp->gw6mac and IP6 -> READY
memcpy(ifp->gw6mac, opts, sizeof(ifp->gw6mac));
ifp->gw6_ready = true;
if (ifp->state6 == MG_TCPIP_STATE_IP) {
ifp->state6 = MG_TCPIP_STATE_READY;
onstate6change(ifp);
@@ -843,6 +853,7 @@ static void rx_ndp_ra(struct mg_tcpip_if *ifp, struct pkt *pkt) {
// Received router's MAC address
ifp->state6 = MG_TCPIP_STATE_READY;
memcpy(ifp->gw6mac, opts + 2, 6);
ifp->gw6_ready = true;
} else if (type == 5 && length >= 8) {
// process MTU if available
uint32_t mtu = mg_ntohl(*(uint32_t *) (opts + 4));
@@ -889,6 +900,11 @@ static void rx_icmp6(struct mg_tcpip_if *ifp, struct pkt *pkt) {
size_t hlen =
sizeof(struct eth) + sizeof(struct ip6) + sizeof(struct icmp6);
size_t space = ifp->tx.len - hlen, plen = pkt->pay.len;
struct mg_addr ips;
ips.ip6[0] = pkt->ip6->src[0], ips.ip6[1] = pkt->ip6->src[1];
ips.is_ip6 = true;
if (get_return_mac(ifp, &ips, false, pkt) == NULL)
return; // safety net for lousy networks
if (plen > space) plen = space; // Copy (truncated) RX payload to TX
// Echo Reply, 4.2
tx_icmp6(ifp, pkt->eth->src, pkt->ip6->dst, pkt->ip6->src, 129, 0,
@@ -913,7 +929,7 @@ static void onstate6change(struct mg_tcpip_if *ifp) {
MG_INFO((" GW: %M", mg_print_ip6, &ifp->gw6));
MG_INFO((" MAC: %M", mg_print_mac, &ifp->mac));
} else if (ifp->state6 == MG_TCPIP_STATE_IP) {
if (ifp->gw6[0] != 0 || ifp->gw6[1] != 0)
if (ifp->gw6[0] != 0 || ifp->gw6[1] != 0)
tx_ndp_ns(ifp, ifp->gw6, ifp->gw6mac); // unsolicited GW MAC resolution
} else if (ifp->state6 == MG_TCPIP_STATE_UP) {
MG_INFO(("IP: %M", mg_print_ip6, &ifp->ip6ll));
@@ -923,9 +939,43 @@ static void onstate6change(struct mg_tcpip_if *ifp) {
}
#endif
static uint8_t *get_return_mac(struct mg_tcpip_if *ifp, struct mg_addr *rem,
bool is_udp, struct pkt *pkt) {
#if MG_ENABLE_IPV6
if (rem->is_ip6) {
if (is_udp && MG_IP6MATCH(rem->ip6, ip6_allnodes.u)) // local broadcast
return (uint8_t *) ip6mac_allnodes;
if (rem->ip6[0] == ifp->ip6[0]) // TODO(): HANDLE PREFIX ***
return pkt->eth->src; // we're on the same LAN, get MAC from frame
if (is_udp && *((uint8_t *) rem->ip6) == 0xFF) // multicast
{
} // TODO(): ip6_mcastmac(s->mac, c->rem.ip6), l2 PR handles this better
if (ifp->gw6_ready) // use the router
return ifp->gw6mac; // ignore source MAC in frame
} else
#endif
{
uint32_t rem_ip = rem->ip4;
if (is_udp && (rem_ip == 0xffffffff || rem_ip == (ifp->ip | ~ifp->mask)))
return (uint8_t *) broadcast; // global or local broadcast
if (ifp->ip != 0 && ((rem_ip & ifp->mask) == (ifp->ip & ifp->mask)))
return pkt->eth->src; // we're on the same LAN, get MAC from frame
if (is_udp &&
(*((uint8_t *) &rem_ip) & 0xE0) == 0xE0) // 224 to 239, E0 to EF
{
} // TODO(): ip4_mcastmac(s->mac, &rem_ip); // multicast group, l2 PR
if (ifp->gw_ready) // use the router, ignore source MAC
return ifp->gwmac;
}
MG_ERROR(("%M %s: No way back, can't respond", mg_print_ip_port, rem,
is_udp ? "UDP" : "TCP"));
return NULL;
}
static bool rx_udp(struct mg_tcpip_if *ifp, struct pkt *pkt) {
struct mg_connection *c = getpeer(ifp->mgr, pkt, true);
struct connstate *s;
uint8_t *mac;
if (c == NULL) return false; // No UDP listener on this port
s = (struct connstate *) (c + 1);
c->rem.port = pkt->udp->sport;
@@ -938,7 +988,9 @@ static bool rx_udp(struct mg_tcpip_if *ifp, struct pkt *pkt) {
{
c->rem.ip4 = pkt->ip->src;
}
memcpy(s->mac, pkt->eth->src, sizeof(s->mac));
if ((mac = get_return_mac(ifp, &c->rem, true, pkt)) == NULL)
return false; // safety net for lousy networks
memcpy(s->mac, mac, sizeof(s->mac));
if (c->recv.len >= MG_MAX_RECV_SIZE) {
mg_error(c, "max_recv_buf_size reached");
} else if (c->recv.size - c->recv.len < pkt->pay.len &&
@@ -1027,6 +1079,7 @@ static size_t tx_tcp_ctrlresp(struct mg_tcpip_if *ifp, struct pkt *pkt,
uint32_t ackno = mg_htonl(mg_ntohl(pkt->tcp->seq) + (uint32_t) pkt->pay.len +
((pkt->tcp->flags & (TH_SYN | TH_FIN)) ? 1 : 0));
struct mg_addr ips, ipd;
uint8_t *mac;
memset(&ips, 0, sizeof(ips));
memset(&ipd, 0, sizeof(ipd));
if (pkt->ip != NULL) {
@@ -1040,7 +1093,9 @@ static size_t tx_tcp_ctrlresp(struct mg_tcpip_if *ifp, struct pkt *pkt,
}
ips.port = pkt->tcp->dport;
ipd.port = pkt->tcp->sport;
return tx_tcp(ifp, pkt->eth->src, &ips, &ipd, flags, seqno, ackno, NULL, 0);
if ((mac = get_return_mac(ifp, &ipd, false, pkt)) == NULL)
return 0; // safety net for lousy networks
return tx_tcp(ifp, mac, &ips, &ipd, flags, seqno, ackno, NULL, 0);
}
static size_t tx_tcp_rst(struct mg_tcpip_if *ifp, struct pkt *pkt, bool toack) {
@@ -1052,6 +1107,7 @@ static struct mg_connection *accept_conn(struct mg_connection *lsn,
struct pkt *pkt, uint16_t mss) {
struct mg_connection *c = mg_alloc_conn(lsn->mgr);
struct connstate *s;
uint8_t *mac;
if (c == NULL) {
MG_ERROR(("OOM"));
return NULL;
@@ -1059,8 +1115,6 @@ static struct mg_connection *accept_conn(struct mg_connection *lsn,
s = (struct connstate *) (c + 1);
s->dmss = mss; // from options in client SYN
s->seq = mg_ntohl(pkt->tcp->ack), s->ack = mg_ntohl(pkt->tcp->seq);
memcpy(s->mac, pkt->eth->src, sizeof(s->mac));
settmout(c, MIP_TTYPE_KEEPALIVE);
#if MG_ENABLE_IPV6
if (lsn->loc.is_ip6) {
c->rem.ip6[0] = pkt->ip6->src[0], c->rem.ip6[1] = pkt->ip6->src[1],
@@ -1076,6 +1130,12 @@ static struct mg_connection *accept_conn(struct mg_connection *lsn,
}
c->rem.port = pkt->tcp->sport;
c->loc.port = lsn->loc.port;
if ((mac = get_return_mac(lsn->mgr->ifp, &c->rem, false, pkt)) == NULL) {
free(c); // safety net for lousy networks, not actually needed
return NULL; // as path has already been checked at SYN (sending SYN+ACK)
}
memcpy(s->mac, mac, sizeof(s->mac));
settmout(c, MIP_TTYPE_KEEPALIVE);
MG_DEBUG(("%lu accepted %M", c->id, mg_print_ip_port, &c->rem));
LIST_ADD_HEAD(struct mg_connection, &lsn->mgr->conns, c);
c->is_accepted = 1;
@@ -1387,7 +1447,8 @@ static void rx_tcp(struct mg_tcpip_if *ifp, struct pkt *pkt) {
// Use peer's src port and bl key as ISN, to later identify the
// handshake
isn = (mg_htonl(((uint32_t) key << 16) | mg_ntohs(pkt->tcp->sport)));
tx_tcp_ctrlresp(ifp, pkt, TH_SYN | TH_ACK, isn);
if (tx_tcp_ctrlresp(ifp, pkt, TH_SYN | TH_ACK, isn) == 0)
backlog_remove(c, (uint16_t) key); // safety net for lousy networks
} // what should we do when port=0 ? Linux takes port 0 as any other
// port
} else if (pkt->tcp->flags == TH_ACK) {
@@ -1421,10 +1482,10 @@ static void rx_ip(struct mg_tcpip_if *ifp, struct pkt *pkt) {
if (ihl < 5) return; // bad IHL
if (pkt->pay.len < (uint16_t) (ihl * 4)) return; // Truncated / malformed
// There can be link padding, take length from IP header
len = mg_ntohs(pkt->ip->len); // IP datagram length
len = mg_ntohs(pkt->ip->len); // IP datagram length
if (len < (uint16_t) (ihl * 4) || len > pkt->pay.len) return; // malformed
pkt->pay.len = len; // strip padding
mkpay(pkt, (uint32_t *) pkt->ip + ihl); // account for opts
pkt->pay.len = len; // strip padding
mkpay(pkt, (uint32_t *) pkt->ip + ihl); // account for opts
frag = mg_ntohs(pkt->ip->frag);
if (frag & IP_MORE_FRAGS_MSK || frag & IP_FRAG_OFFSET_MSK) {
struct mg_connection *c;
@@ -1691,15 +1752,21 @@ static void mg_tcpip_poll(struct mg_tcpip_if *ifp, uint64_t now) {
}
// Handle gw ARP request timeout, order is important
if (expired_1000ms && ifp->state == MG_TCPIP_STATE_IP) {
ifp->state = MG_TCPIP_STATE_READY; // keep best-effort MAC
ifp->state = MG_TCPIP_STATE_READY; // keep best-effort MAC or poison mark
onstatechange(ifp);
}
if (expired_1000ms && ifp->state == MG_TCPIP_STATE_READY && !ifp->gw_ready &&
ifp->gw != 0)
mg_tcpip_arp_request(ifp, ifp->gw, NULL); // retry GW ARP request
#if MG_ENABLE_IPV6
// Handle gw NS/NA req/resp timeout, order is important
if (expired_1000ms && ifp->state6 == MG_TCPIP_STATE_IP) {
ifp->state6 = MG_TCPIP_STATE_READY; // keep best-effort MAC
ifp->state6 = MG_TCPIP_STATE_READY; // keep best-effort MAC or poison mark
onstate6change(ifp);
}
if (expired_1000ms && ifp->state == MG_TCPIP_STATE_READY && !ifp->gw6_ready &&
(ifp->gw6[0] != 0 || ifp->gw6[1] != 0))
tx_ndp_ns(ifp, ifp->gw6, ifp->gw6mac); // retry GW MAC resolution
#endif
// poll driver
@@ -1813,9 +1880,8 @@ void mg_tcpip_init(struct mg_mgr *mgr, struct mg_tcpip_if *ifp) {
ifp->mtu = MG_TCPIP_MTU_DEFAULT;
mgr->extraconnsize = sizeof(struct connstate);
if (ifp->ip == 0) ifp->enable_dhcp_client = true;
memset(ifp->gwmac, 255, sizeof(ifp->gwmac)); // Set best-effort to bcast
mg_random(&ifp->eport, sizeof(ifp->eport)); // Random from 0 to 65535
ifp->eport |= MG_EPHEMERAL_PORT_BASE; // Random from
mg_random(&ifp->eport, sizeof(ifp->eport)); // Random from 0 to 65535
ifp->eport |= MG_EPHEMERAL_PORT_BASE; // Random from
// MG_EPHEMERAL_PORT_BASE to 65535
if (ifp->tx.buf == NULL || ifp->recv_queue.buf == NULL) MG_ERROR(("OOM"));
#if MG_ENABLE_IPV6
@@ -1825,7 +1891,6 @@ void mg_tcpip_init(struct mg_mgr *mgr, struct mg_tcpip_if *ifp) {
ifp->enable_slaac = true;
ip6genll((uint8_t *) ifp->ip6ll, ifp->mac); // build link-local address
}
memset(ifp->gw6mac, 255, sizeof(ifp->gw6mac)); // Set best-effort to bcast
#endif
}
}
@@ -1884,7 +1949,7 @@ void mg_connect_resolved(struct mg_connection *c) {
struct connstate *s = (struct connstate *) (c + 1);
memcpy(s->mac, ip6mac_allnodes, sizeof(s->mac));
mac_resolved(c);
} else if (c->rem.ip6[0] == ifp->ip6[0] &&
} else if (c->rem.ip6[0] == ifp->ip6[0] && // TODO(): HANDLE PREFIX ***
!MG_IP6MATCH(c->rem.ip6,
ifp->gw6)) { // skip if gw (onstate6change -> NS)
// If we're in the same LAN, fire a Neighbor Solicitation
@@ -1892,11 +1957,11 @@ void mg_connect_resolved(struct mg_connection *c) {
tx_ndp_ns(ifp, c->rem.ip6, ifp->mac);
settmout(c, MIP_TTYPE_ARP);
c->is_arplooking = 1;
} else if (*((uint8_t *) c->rem.ip6) == 0xFF) { // multicast
} else if (c->is_udp && *((uint8_t *) c->rem.ip6) == 0xFF) { // multicast
struct connstate *s = (struct connstate *) (c + 1);
ip6_mcastmac(s->mac, c->rem.ip6);
mac_resolved(c);
} else if (ifp->gw6[0] != 0 || ifp->gw6[1] != 0) {
} else if (ifp->gw6_ready) {
struct connstate *s = (struct connstate *) (c + 1);
memcpy(s->mac, ifp->gw6mac, sizeof(s->mac));
mac_resolved(c);
@@ -1919,14 +1984,14 @@ void mg_connect_resolved(struct mg_connection *c) {
mg_tcpip_arp_request(ifp, rem_ip, NULL);
settmout(c, MIP_TTYPE_ARP);
c->is_arplooking = 1;
} else if ((*((uint8_t *) &rem_ip) & 0xE0) == 0xE0) {
} else if (c->is_udp && (*((uint8_t *) &rem_ip) & 0xE0) == 0xE0) {
struct connstate *s =
(struct connstate *) (c + 1); // 224 to 239, E0 to EF
ip4_mcastmac(s->mac, &rem_ip); // multicast group
mac_resolved(c);
} else if (ifp->gw != 0) {
} else if (ifp->gw_ready) {
struct connstate *s = (struct connstate *) (c + 1);
memcpy(s->mac, ifp->gwmac, sizeof(ifp->gwmac));
memcpy(s->mac, ifp->gwmac, sizeof(s->mac));
mac_resolved(c);
} else {
MG_ERROR(("No gateway, can't connect"));
src/net_builtin.h
+2
View File
@@ -80,9 +80,11 @@ struct mg_tcpip_if {
#define MG_TCPIP_STATE_REQ 2 // Interface is up, DHCP REQUESTING state
#define MG_TCPIP_STATE_IP 3 // Interface is up and has an IP assigned
#define MG_TCPIP_STATE_READY 4 // Interface has fully come up, ready to work
bool gw_ready; // We've got a hw address for the router
#if MG_ENABLE_IPV6
uint8_t gw6mac[6]; // IPv6 Router's MAC
uint8_t state6; // Current IPv6 state
bool gw6_ready; // We've got a hw address for the IPv6 router
#endif
};
void mg_tcpip_init(struct mg_mgr *, struct mg_tcpip_if *);
test/mip_test.c
+2
View File
@@ -252,6 +252,7 @@ static void init_tests(struct mg_mgr *mgr, struct eth *e, struct ipp *ipp,
if (ipp->ip6 != NULL) {
mif->ip6[0] = 1;
mif->gw6[0] = 1;
mif->gw6_ready = true;
mif->state = MG_TCPIP_STATE_READY; // so DHCP stops
mif->state6 = MG_TCPIP_STATE_READY; // so mg_send() works and RS stops
} else
@@ -259,6 +260,7 @@ static void init_tests(struct mg_mgr *mgr, struct eth *e, struct ipp *ipp,
{
mif->ip = 1;
mif->gw = 1;
mif->gw_ready = true;
mif->mask = 255; // use router, to avoid firing an ARP request
mif->state = MG_TCPIP_STATE_READY; // so mg_send() works and DHCP stops
}