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9dc86aa77dfe7745feb72a33939cc16b6b23fdf2
mongoose/mip/mip.c
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cpq 9dc86aa77d Kill ARP cache, kill qprofile
2023-02-07 14:26:03 +00:00

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#include "mip.h"
#if MG_ENABLE_MIP
#define MIP_EPHEMERAL_PORT 49152
#define PDIFF(a, b) ((size_t) (((char *) (b)) - ((char *) (a))))
#ifndef MIP_TCP_KEEPALIVE_MS
#define MIP_TCP_KEEPALIVE_MS 45000 // TCP keep-alive period, ms
#endif
#define MIP_TCP_ACK_MS 150 // Timeout for ACKing
struct connstate {
uint32_t seq, ack; // TCP seq/ack counters
uint64_t timer; // TCP keep-alive / ACK timer
uint8_t mac[6]; // Peer MAC address
uint8_t ttype; // Timer type. 0: ack, 1: keep-alive
#define MIP_TTYPE_KEEPALIVE 0 // Connection is idle for long, send keepalive
#define MIP_TTYPE_ACK 1 // Peer sent us data, we have to ack it soon
uint8_t tmiss; // Number of keep-alive misses
struct mg_iobuf raw; // For TLS only. Incoming raw data
};
#pragma pack(push, 1)
struct lcp {
uint8_t addr, ctrl, proto[2], code, id, len[2];
};
struct eth {
uint8_t dst[6]; // Destination MAC address
uint8_t src[6]; // Source MAC address
uint16_t type; // Ethernet type
};
struct ip {
uint8_t ver; // Version
uint8_t tos; // Unused
uint16_t len; // Length
uint16_t id; // Unused
uint16_t frag; // Fragmentation
uint8_t ttl; // Time to live
uint8_t proto; // Upper level protocol
uint16_t csum; // Checksum
uint32_t src; // Source IP
uint32_t dst; // Destination IP
};
struct ip6 {
uint8_t ver; // Version
uint8_t opts[3]; // Options
uint16_t len; // Length
uint8_t proto; // Upper level protocol
uint8_t ttl; // Time to live
uint8_t src[16]; // Source IP
uint8_t dst[16]; // Destination IP
};
struct icmp {
uint8_t type;
uint8_t code;
uint16_t csum;
};
struct arp {
uint16_t fmt; // Format of hardware address
uint16_t pro; // Format of protocol address
uint8_t hlen; // Length of hardware address
uint8_t plen; // Length of protocol address
uint16_t op; // Operation
uint8_t sha[6]; // Sender hardware address
uint32_t spa; // Sender protocol address
uint8_t tha[6]; // Target hardware address
uint32_t tpa; // Target protocol address
};
struct tcp {
uint16_t sport; // Source port
uint16_t dport; // Destination port
uint32_t seq; // Sequence number
uint32_t ack; // Acknowledgement number
uint8_t off; // Data offset
uint8_t flags; // TCP flags
#define TH_FIN 0x01
#define TH_SYN 0x02
#define TH_RST 0x04
#define TH_PUSH 0x08
#define TH_ACK 0x10
#define TH_URG 0x20
#define TH_ECE 0x40
#define TH_CWR 0x80
uint16_t win; // Window
uint16_t csum; // Checksum
uint16_t urp; // Urgent pointer
};
struct udp {
uint16_t sport; // Source port
uint16_t dport; // Destination port
uint16_t len; // UDP length
uint16_t csum; // UDP checksum
};
struct dhcp {
uint8_t op, htype, hlen, hops;
uint32_t xid;
uint16_t secs, flags;
uint32_t ciaddr, yiaddr, siaddr, giaddr;
uint8_t hwaddr[208];
uint32_t magic;
uint8_t options[32];
};
#pragma pack(pop)
struct pkt {
struct mg_str raw; // Raw packet data
struct mg_str pay; // Payload data
struct eth *eth;
struct llc *llc;
struct arp *arp;
struct ip *ip;
struct ip6 *ip6;
struct icmp *icmp;
struct tcp *tcp;
struct udp *udp;
struct dhcp *dhcp;
};
static void q_copyin(struct queue *q, const uint8_t *buf, size_t len,
size_t head) {
size_t left = q->len - head;
memcpy(&q->buf[head], buf, left < len ? left : len);
if (left < len) memcpy(q->buf, &buf[left], len - left);
}
static void q_copyout(struct queue *q, uint8_t *buf, size_t len, size_t tail) {
size_t left = q->len - tail;
memcpy(buf, &q->buf[tail], left < len ? left : len);
if (left < len) memcpy(&buf[left], q->buf, len - left);
}
static bool q_write(struct queue *q, const void *buf, size_t len) {
bool success = false;
size_t left = (q->len - q->head + q->tail - 1) % q->len;
if (len + sizeof(size_t) <= left) {
q_copyin(q, (uint8_t *) &len, sizeof(len), q->head);
q_copyin(q, (uint8_t *) buf, len, (q->head + sizeof(size_t)) % q->len);
q->head = (q->head + sizeof(len) + len) % q->len;
success = true;
}
return success;
}
static inline size_t q_avail(struct queue *q) {
size_t n = 0;
if (q->tail != q->head) q_copyout(q, (uint8_t *) &n, sizeof(n), q->tail);
return n;
}
static size_t q_read(struct queue *q, void *buf) {
size_t n = q_avail(q);
if (n > 0) {
q_copyout(q, (uint8_t *) buf, n, (q->tail + sizeof(n)) % q->len);
q->tail = (q->tail + sizeof(n) + n) % q->len;
}
return n;
}
static struct mg_str mkstr(void *buf, size_t len) {
struct mg_str str = {(char *) buf, len};
return str;
}
static void mkpay(struct pkt *pkt, void *p) {
pkt->pay = mkstr(p, (size_t) (&pkt->raw.ptr[pkt->raw.len] - (char *) p));
}
static uint32_t csumup(uint32_t sum, const void *buf, size_t len) {
const uint8_t *p = (const uint8_t *) buf;
for (size_t i = 0; i < len; i++) sum += i & 1 ? p[i] : (uint32_t) (p[i] << 8);
return sum;
}
static uint16_t csumfin(uint32_t sum) {
while (sum >> 16) sum = (sum & 0xffff) + (sum >> 16);
return mg_htons(~sum & 0xffff);
}
static uint16_t ipcsum(const void *buf, size_t len) {
uint32_t sum = csumup(0, buf, len);
return csumfin(sum);
}
static size_t ether_output(struct mip_if *ifp, size_t len) {
// size_t min = 64; // Pad short frames to 64 bytes (minimum Ethernet size)
// if (len < min) memset(ifp->tx.ptr + len, 0, min - len), len = min;
// mg_hexdump(ifp->tx.ptr, len);
size_t n = ifp->driver->tx(ifp->tx.ptr, len, ifp);
if (n == len) ifp->nsent++;
return n;
}
static void arp_ask(struct mip_if *ifp, uint32_t ip) {
struct eth *eth = (struct eth *) ifp->tx.ptr;
struct arp *arp = (struct arp *) (eth + 1);
memset(eth->dst, 255, sizeof(eth->dst));
memcpy(eth->src, ifp->mac, sizeof(eth->src));
eth->type = mg_htons(0x806);
memset(arp, 0, sizeof(*arp));
arp->fmt = mg_htons(1), arp->pro = mg_htons(0x800), arp->hlen = 6,
arp->plen = 4;
arp->op = mg_htons(1), arp->tpa = ip, arp->spa = ifp->ip;
memcpy(arp->sha, ifp->mac, sizeof(arp->sha));
ether_output(ifp, PDIFF(eth, arp + 1));
}
static void onstatechange(struct mip_if *ifp) {
if (ifp->state == MIP_STATE_READY) {
MG_INFO(("READY, IP: %M", mg_print_ip4, &ifp->ip));
MG_INFO((" GW: %M", mg_print_ip4, &ifp->gw));
if (ifp->lease_expire > ifp->now) {
MG_INFO(
(" Lease: %lld sec", (ifp->lease_expire - ifp->now) / 1000));
}
arp_ask(ifp, ifp->gw);
} else if (ifp->state == MIP_STATE_UP) {
MG_ERROR(("Link up"));
} else if (ifp->state == MIP_STATE_DOWN) {
MG_ERROR(("Link down"));
}
}
static struct ip *tx_ip(struct mip_if *ifp, uint8_t *mac_dst, uint8_t proto,
uint32_t ip_src, uint32_t ip_dst, size_t plen) {
struct eth *eth = (struct eth *) ifp->tx.ptr;
struct ip *ip = (struct ip *) (eth + 1);
memcpy(eth->dst, mac_dst, sizeof(eth->dst));
memcpy(eth->src, ifp->mac, sizeof(eth->src)); // Use our MAC
eth->type = mg_htons(0x800);
memset(ip, 0, sizeof(*ip));
ip->ver = 0x45; // Version 4, header length 5 words
ip->frag = 0x40; // Don't fragment
ip->len = mg_htons((uint16_t) (sizeof(*ip) + plen));
ip->ttl = 64;
ip->proto = proto;
ip->src = ip_src;
ip->dst = ip_dst;
ip->csum = ipcsum(ip, sizeof(*ip));
return ip;
}
static void tx_udp(struct mip_if *ifp, uint8_t *mac_dst, uint32_t ip_src,
uint16_t sport, uint32_t ip_dst, uint16_t dport,
const void *buf, size_t len) {
struct ip *ip =
tx_ip(ifp, mac_dst, 17, ip_src, ip_dst, len + sizeof(struct udp));
struct udp *udp = (struct udp *) (ip + 1);
// MG_DEBUG(("UDP XX LEN %d %d", (int) len, (int) ifp->tx.len));
udp->sport = sport;
udp->dport = dport;
udp->len = mg_htons((uint16_t) (sizeof(*udp) + len));
udp->csum = 0;
uint32_t cs = csumup(0, udp, sizeof(*udp));
cs = csumup(cs, buf, len);
cs = csumup(cs, &ip->src, sizeof(ip->src));
cs = csumup(cs, &ip->dst, sizeof(ip->dst));
cs += (uint32_t) (ip->proto + sizeof(*udp) + len);
udp->csum = csumfin(cs);
memmove(udp + 1, buf, len);
// MG_DEBUG(("UDP LEN %d %d", (int) len, (int) ifp->frame_len));
ether_output(ifp, sizeof(struct eth) + sizeof(*ip) + sizeof(*udp) + len);
}
static void tx_dhcp(struct mip_if *ifp, uint8_t *mac_dst, uint32_t ip_src,
uint32_t ip_dst, uint8_t *opts, size_t optslen) {
struct dhcp dhcp = {1, 1, 6, 0, 0, 0, 0, 0, 0, 0, 0, {0}, 0, {0}};
dhcp.magic = mg_htonl(0x63825363);
memcpy(&dhcp.hwaddr, ifp->mac, sizeof(ifp->mac));
memcpy(&dhcp.xid, ifp->mac + 2, sizeof(dhcp.xid));
memcpy(&dhcp.options, opts, optslen);
tx_udp(ifp, mac_dst, ip_src, mg_htons(68), ip_dst, mg_htons(67), &dhcp,
sizeof(dhcp));
}
static void tx_dhcp_request(struct mip_if *ifp, uint8_t *mac_dst,
uint32_t ip_src, uint32_t ip_dst) {
uint8_t opts[] = {
53, 1, 3, // Type: DHCP request
55, 2, 1, 3, // GW and mask
12, 3, 'm', 'i', 'p', // Host name: "mip"
54, 4, 0, 0, 0, 0, // DHCP server ID
50, 4, 0, 0, 0, 0, // Requested IP
255 // End of options
};
memcpy(opts + 14, &ip_dst, sizeof(ip_dst));
memcpy(opts + 20, &ip_src, sizeof(ip_src));
tx_dhcp(ifp, mac_dst, ip_src, ip_dst, opts, sizeof(opts));
}
static void tx_dhcp_discover(struct mip_if *ifp) {
uint8_t mac[6] = {255, 255, 255, 255, 255, 255};
uint8_t opts[] = {
53, 1, 1, // Type: DHCP discover
55, 2, 1, 3, // Parameters: ip, mask
255 // End of options
};
tx_dhcp(ifp, mac, 0, 0xffffffff, opts, sizeof(opts));
MG_DEBUG(("DHCP discover sent"));
}
static struct mg_connection *getpeer(struct mg_mgr *mgr, struct pkt *pkt,
bool lsn) {
struct mg_connection *c = NULL;
for (c = mgr->conns; c != NULL; c = c->next) {
if (c->is_udp && pkt->udp && c->loc.port == pkt->udp->dport) break;
if (!c->is_udp && pkt->tcp && c->loc.port == pkt->tcp->dport &&
lsn == c->is_listening && (lsn || c->rem.port == pkt->tcp->sport))
break;
}
return c;
}
static void rx_arp(struct mip_if *ifp, struct pkt *pkt) {
if (pkt->arp->op == mg_htons(1) && pkt->arp->tpa == ifp->ip) {
// ARP request. Make a response, then send
// MG_DEBUG(("ARP op %d %M: %M", mg_ntohs(pkt->arp->op), mg_print_ip4,
// &pkt->arp->spa, mg_print_ip4, &pkt->arp->tpa));
struct eth *eth = (struct eth *) ifp->tx.ptr;
struct arp *arp = (struct arp *) (eth + 1);
memcpy(eth->dst, pkt->eth->src, sizeof(eth->dst));
memcpy(eth->src, ifp->mac, sizeof(eth->src));
eth->type = mg_htons(0x806);
*arp = *pkt->arp;
arp->op = mg_htons(2);
memcpy(arp->tha, pkt->arp->sha, sizeof(pkt->arp->tha));
memcpy(arp->sha, ifp->mac, sizeof(pkt->arp->sha));
arp->tpa = pkt->arp->spa;
arp->spa = ifp->ip;
MG_DEBUG(("ARP: tell %M we're %M", mg_print_ip4, &arp->tpa, mg_print_ip4,
&ifp->ip));
ether_output(ifp, PDIFF(eth, arp + 1));
} else if (pkt->arp->op == mg_htons(2)) {
if (memcmp(pkt->arp->tha, ifp->mac, sizeof(pkt->arp->tha)) != 0) return;
if (pkt->arp->spa == ifp->gw) {
// Got response for the GW ARP request. Set ifp->gwmac
memcpy(ifp->gwmac, pkt->arp->sha, sizeof(ifp->gwmac));
} else {
struct mg_connection *c = getpeer(ifp->mgr, pkt, false);
if (c != NULL && c->is_arplooking) {
struct connstate *s = (struct connstate *) (c + 1);
memcpy(s->mac, pkt->arp->sha, sizeof(s->mac));
MG_DEBUG(("%lu ARP resolved %M -> %M", c->id, mg_print_ip4, &c->rem.ip,
mg_print_mac, s->mac));
c->is_arplooking = 0;
}
}
}
}
static void rx_icmp(struct mip_if *ifp, struct pkt *pkt) {
// MG_DEBUG(("ICMP %d", (int) len));
if (pkt->icmp->type == 8 && pkt->ip != NULL && pkt->ip->dst == ifp->ip) {
size_t hlen = sizeof(struct eth) + sizeof(struct ip) + sizeof(struct icmp);
size_t space = ifp->tx.len - hlen, plen = pkt->pay.len;
if (plen > space) plen = space;
struct ip *ip = tx_ip(ifp, pkt->eth->src, 1, ifp->ip, pkt->ip->src,
sizeof(struct icmp) + plen);
struct icmp *icmp = (struct icmp *) (ip + 1);
memset(icmp, 0, sizeof(*icmp)); // Set csum to 0
memcpy(icmp + 1, pkt->pay.ptr, plen); // Copy RX payload to TX
icmp->csum = ipcsum(icmp, sizeof(*icmp) + plen);
ether_output(ifp, hlen + plen);
}
}
static void rx_dhcp_client(struct mip_if *ifp, struct pkt *pkt) {
uint32_t ip = 0, gw = 0, mask = 0;
uint8_t *p = pkt->dhcp->options,
*end = (uint8_t *) &pkt->raw.ptr[pkt->raw.len];
if (end < (uint8_t *) (pkt->dhcp + 1)) return;
while (p + 1 < end && p[0] != 255) { // Parse options
if (p[0] == 1 && p[1] == sizeof(ifp->mask) && p + 6 < end) { // Mask
memcpy(&mask, p + 2, sizeof(mask));
} else if (p[0] == 3 && p[1] == sizeof(ifp->gw) && p + 6 < end) { // GW
memcpy(&gw, p + 2, sizeof(gw));
ip = pkt->dhcp->yiaddr;
} else if (p[0] == 51 && p[1] == 4 && p + 6 < end) { // Lease
uint32_t lease = 0;
memcpy(&lease, p + 2, sizeof(lease));
ifp->lease_expire = ifp->now + mg_ntohl(lease) * 1000;
}
p += p[1] + 2;
}
if (ip && mask && gw && ifp->ip == 0) {
memcpy(ifp->gwmac, pkt->eth->src, sizeof(ifp->gwmac));
ifp->ip = ip, ifp->gw = gw, ifp->mask = mask;
ifp->state = MIP_STATE_READY;
onstatechange(ifp);
tx_dhcp_request(ifp, pkt->eth->src, ip, pkt->dhcp->siaddr);
}
}
// Simple DHCP server that assigns a next IP address: ifp->ip + 1
static void rx_dhcp_server(struct mip_if *ifp, struct pkt *pkt) {
uint8_t op = 0, *p = pkt->dhcp->options,
*end = (uint8_t *) &pkt->raw.ptr[pkt->raw.len];
if (end < (uint8_t *) (pkt->dhcp + 1)) return;
// struct dhcp *req = pkt->dhcp;
struct dhcp res = {2, 1, 6, 0, 0, 0, 0, 0, 0, 0, 0, {0}, 0, {0}};
res.yiaddr = ifp->ip;
((uint8_t *) (&res.yiaddr))[3]++; // Offer our IP + 1
while (p + 1 < end && p[0] != 255) { // Parse options
if (p[0] == 53 && p[1] == 1 && p + 2 < end) { // Message type
op = p[2];
}
p += p[1] + 2;
}
if (op == 1 || op == 3) { // DHCP Discover or DHCP Request
uint8_t msg = op == 1 ? 2 : 5; // Message type: DHCP OFFER or DHCP ACK
uint8_t opts[] = {
53, 1, msg, // Message type
1, 4, 0, 0, 0, 0, // Subnet mask
54, 4, 0, 0, 0, 0, // Server ID
12, 3, 'm', 'i', 'p', // Host name: "mip"
51, 4, 255, 255, 255, 255, // Lease time
255 // End of options
};
memcpy(&res.hwaddr, pkt->dhcp->hwaddr, 6);
memcpy(opts + 5, &ifp->mask, sizeof(ifp->mask));
memcpy(opts + 11, &ifp->ip, sizeof(ifp->ip));
memcpy(&res.options, opts, sizeof(opts));
res.magic = pkt->dhcp->magic;
res.xid = pkt->dhcp->xid;
// memcpy(ifp->gwmac, pkt->eth->src, sizeof(ifp->gwmac));
tx_udp(ifp, pkt->eth->src, ifp->ip, mg_htons(67),
op == 1 ? ~0U : res.yiaddr, mg_htons(68), &res, sizeof(res));
}
}
static void rx_udp(struct mip_if *ifp, struct pkt *pkt) {
struct mg_connection *c = getpeer(ifp->mgr, pkt, true);
if (c == NULL) {
// No UDP listener on this port. Should send ICMP, but keep silent.
} else if (c != NULL) {
c->rem.port = pkt->udp->sport;
c->rem.ip = pkt->ip->src;
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 &&
!mg_iobuf_resize(&c->recv, c->recv.len + pkt->pay.len)) {
mg_error(c, "oom");
} else {
memcpy(&c->recv.buf[c->recv.len], pkt->pay.ptr, pkt->pay.len);
c->recv.len += pkt->pay.len;
mg_call(c, MG_EV_READ, &pkt->pay.len);
}
}
}
static size_t tx_tcp(struct mip_if *ifp, uint8_t *dst_mac, uint32_t dst_ip,
uint8_t flags, uint16_t sport, uint16_t dport,
uint32_t seq, uint32_t ack, const void *buf, size_t len) {
struct ip *ip =
tx_ip(ifp, dst_mac, 6, ifp->ip, dst_ip, sizeof(struct tcp) + len);
struct tcp *tcp = (struct tcp *) (ip + 1);
memset(tcp, 0, sizeof(*tcp));
if (buf != NULL && len) memmove(tcp + 1, buf, len);
tcp->sport = sport;
tcp->dport = dport;
tcp->seq = seq;
tcp->ack = ack;
tcp->flags = flags;
tcp->win = mg_htons(8192);
tcp->off = (uint8_t) (sizeof(*tcp) / 4 << 4);
uint32_t cs = 0;
uint16_t n = (uint16_t) (sizeof(*tcp) + len);
uint8_t pseudo[] = {0, ip->proto, (uint8_t) (n >> 8), (uint8_t) (n & 255)};
cs = csumup(cs, tcp, n);
cs = csumup(cs, &ip->src, sizeof(ip->src));
cs = csumup(cs, &ip->dst, sizeof(ip->dst));
cs = csumup(cs, pseudo, sizeof(pseudo));
tcp->csum = csumfin(cs);
return ether_output(ifp, PDIFF(ifp->tx.ptr, tcp + 1) + len);
}
static size_t tx_tcp_pkt(struct mip_if *ifp, struct pkt *pkt, uint8_t flags,
uint32_t seq, const void *buf, size_t len) {
uint32_t delta = (pkt->tcp->flags & (TH_SYN | TH_FIN)) ? 1 : 0;
return tx_tcp(ifp, pkt->eth->src, pkt->ip->src, flags, pkt->tcp->dport,
pkt->tcp->sport, seq, mg_htonl(mg_ntohl(pkt->tcp->seq) + delta),
buf, len);
}
static void settmout(struct mg_connection *c, uint8_t type) {
struct mip_if *ifp = (struct mip_if *) c->mgr->priv;
struct connstate *s = (struct connstate *) (c + 1);
unsigned n = type == MIP_TTYPE_ACK ? MIP_TCP_ACK_MS : MIP_TCP_KEEPALIVE_MS;
s->timer = ifp->now + n;
s->ttype = type;
MG_VERBOSE(("%lu %d -> %llx", c->id, type, s->timer));
}
static struct mg_connection *accept_conn(struct mg_connection *lsn,
struct pkt *pkt) {
struct mg_connection *c = mg_alloc_conn(lsn->mgr);
struct connstate *s = (struct connstate *) (c + 1);
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);
c->rem.ip = pkt->ip->src;
c->rem.port = pkt->tcp->sport;
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;
c->is_hexdumping = lsn->is_hexdumping;
c->pfn = lsn->pfn;
c->loc = lsn->loc;
c->pfn_data = lsn->pfn_data;
c->fn = lsn->fn;
c->fn_data = lsn->fn_data;
mg_call(c, MG_EV_OPEN, NULL);
mg_call(c, MG_EV_ACCEPT, NULL);
return c;
}
long mg_io_send(struct mg_connection *c, const void *buf, size_t len) {
struct mip_if *ifp = (struct mip_if *) c->mgr->priv;
struct connstate *s = (struct connstate *) (c + 1);
size_t max_headers_len = 14 + 24 /* max IP */ + 60 /* max TCP */;
if (len + max_headers_len > ifp->tx.len) len = ifp->tx.len - max_headers_len;
if (tx_tcp(ifp, s->mac, c->rem.ip, TH_PUSH | TH_ACK, c->loc.port, c->rem.port,
mg_htonl(s->seq), mg_htonl(s->ack), buf, len) > 0) {
s->seq += (uint32_t) len;
if (s->ttype == MIP_TTYPE_ACK) settmout(c, MIP_TTYPE_KEEPALIVE);
} else {
return MG_IO_ERR;
}
return (long) len;
}
long mg_io_recv(struct mg_connection *c, void *buf, size_t len) {
struct connstate *s = (struct connstate *) (c + 1);
if (s->raw.len == 0) return MG_IO_WAIT;
if (len > s->raw.len) len = s->raw.len;
memcpy(buf, s->raw.buf, len);
mg_iobuf_del(&s->raw, 0, len);
MG_DEBUG(("%lu", len));
return (long) len;
}
static void read_conn(struct mg_connection *c, struct pkt *pkt) {
struct connstate *s = (struct connstate *) (c + 1);
struct mg_iobuf *io = c->is_tls ? &s->raw : &c->recv;
uint32_t seq = mg_ntohl(pkt->tcp->seq);
s->raw.align = c->recv.align;
if (pkt->tcp->flags & TH_FIN) {
s->ack = mg_htonl(pkt->tcp->seq) + 1, s->seq = mg_htonl(pkt->tcp->ack);
c->is_closing = 1;
} else if (pkt->pay.len == 0) {
// TODO(cpq): handle this peer's ACK
} else if (seq != s->ack) {
uint32_t ack = (uint32_t) (mg_htonl(pkt->tcp->seq) + pkt->pay.len);
if (s->ack == ack) {
MG_VERBOSE(("ignoring duplicate pkt"));
} else {
// TODO(cpq): peer sent us SEQ which we don't expect. Retransmit rather
// than close this connection
mg_error(c, "SEQ != ACK: %x %x %x", seq, s->ack, ack);
}
} else if (io->size - io->len < pkt->pay.len &&
!mg_iobuf_resize(io, io->len + pkt->pay.len)) {
mg_error(c, "oom");
} else {
// Copy TCP payload into the IO buffer. If the connection is plain text, we
// copy to c->recv. If the connection is TLS, this data is encrypted,
// therefore we copy that encrypted data to the s->raw iobuffer instead,
// and then call mg_tls_recv() to decrypt it. NOTE: mg_tls_recv() will
// call back mg_io_recv() which grabs raw data from s->raw
memcpy(&io->buf[io->len], pkt->pay.ptr, pkt->pay.len);
io->len += pkt->pay.len;
MG_DEBUG(("%lu SEQ %x -> %x", c->id, mg_htonl(pkt->tcp->seq), s->ack));
// Advance ACK counter
s->ack = (uint32_t) (mg_htonl(pkt->tcp->seq) + pkt->pay.len);
#if 0
// Send ACK immediately
MG_DEBUG((" imm ACK", c->id, mg_htonl(pkt->tcp->seq), s->ack));
tx_tcp((struct mip_if *) c->mgr->priv, c->rem.ip, TH_ACK, c->loc.port,
c->rem.port, mg_htonl(s->seq), mg_htonl(s->ack), "", 0);
#else
// if not already running, setup a timer to send an ACK later
if (s->ttype != MIP_TTYPE_ACK) settmout(c, MIP_TTYPE_ACK);
#endif
if (c->is_tls) {
// TLS connection. Make room for decrypted data in c->recv
io = &c->recv;
if (io->size - io->len < pkt->pay.len &&
!mg_iobuf_resize(io, io->len + pkt->pay.len)) {
mg_error(c, "oom");
} else {
// Decrypt data directly into c->recv
long n = mg_tls_recv(c, &io->buf[io->len], io->size - io->len);
if (n == MG_IO_ERR) {
mg_error(c, "TLS recv error");
} else if (n > 0) {
// Decrypted successfully - trigger MG_EV_READ
io->len += (size_t) n;
mg_call(c, MG_EV_READ, &n);
}
}
} else {
// Plain text connection, data is already in c->recv, trigger MG_EV_READ
mg_call(c, MG_EV_READ, &pkt->pay.len);
}
}
}
static void rx_tcp(struct mip_if *ifp, struct pkt *pkt) {
struct mg_connection *c = getpeer(ifp->mgr, pkt, false);
struct connstate *s = c == NULL ? NULL : (struct connstate *) (c + 1);
#if 0
MG_INFO(("%lu %hhu %d", c ? c->id : 0, pkt->tcp->flags, (int) pkt->pay.len));
#endif
if (c != NULL && c->is_connecting && pkt->tcp->flags & (TH_SYN | TH_ACK)) {
s->seq = mg_ntohl(pkt->tcp->ack), s->ack = mg_ntohl(pkt->tcp->seq) + 1;
tx_tcp_pkt(ifp, pkt, TH_ACK, pkt->tcp->ack, NULL, 0);
c->is_connecting = 0; // Client connected
settmout(c, MIP_TTYPE_KEEPALIVE);
mg_call(c, MG_EV_CONNECT, NULL); // Let user know
} else if (c != NULL && c->is_connecting) {
tx_tcp_pkt(ifp, pkt, TH_RST | TH_ACK, pkt->tcp->ack, NULL, 0);
} else if (c != NULL && pkt->tcp->flags & TH_RST) {
mg_error(c, "peer RST"); // RFC-1122 4.2.2.13
} else if (c != NULL) {
#if 0
MG_DEBUG(("%lu %d %M:%hu -> %M:%hu", c->id, (int) pkt->raw.len,
mg_print_ip4, &pkt->ip->src, mg_ntohs(pkt->tcp->sport),
mg_print_ip4, &pkt->ip->dst, mg_ntohs(pkt->tcp->dport)));
mg_hexdump(pkt->pay.buf, pkt->pay.len);
#endif
s->tmiss = 0; // Reset missed keep-alive counter
if (s->ttype == MIP_TTYPE_KEEPALIVE) // Advance keep-alive timer
settmout(c,
MIP_TTYPE_KEEPALIVE); // unless a former ACK timeout is pending
read_conn(c, pkt); // Override timer with ACK timeout if needed
} else if ((c = getpeer(ifp->mgr, pkt, true)) == NULL) {
tx_tcp_pkt(ifp, pkt, TH_RST | TH_ACK, pkt->tcp->ack, NULL, 0);
} else if (pkt->tcp->flags & TH_RST) {
if (c->is_accepted) mg_error(c, "peer RST"); // RFC-1122 4.2.2.13
// ignore RST if not connected
} else if (pkt->tcp->flags & TH_SYN) {
// Use peer's source port as ISN, in order to recognise the handshake
uint32_t isn = mg_htonl((uint32_t) mg_ntohs(pkt->tcp->sport));
tx_tcp_pkt(ifp, pkt, TH_SYN | TH_ACK, isn, NULL, 0);
} else if (pkt->tcp->flags & TH_FIN) {
tx_tcp_pkt(ifp, pkt, TH_FIN | TH_ACK, pkt->tcp->ack, NULL, 0);
} else if (mg_htonl(pkt->tcp->ack) == mg_htons(pkt->tcp->sport) + 1U) {
accept_conn(c, pkt);
} else if (!c->is_accepted) { // no peer
tx_tcp_pkt(ifp, pkt, TH_RST | TH_ACK, pkt->tcp->ack, NULL, 0);
} else {
// MG_DEBUG(("dropped silently.."));
}
}
static void rx_ip(struct mip_if *ifp, struct pkt *pkt) {
if (pkt->ip->proto == 1) {
pkt->icmp = (struct icmp *) (pkt->ip + 1);
if (pkt->pay.len < sizeof(*pkt->icmp)) return;
mkpay(pkt, pkt->icmp + 1);
rx_icmp(ifp, pkt);
} else if (pkt->ip->proto == 17) {
pkt->udp = (struct udp *) (pkt->ip + 1);
if (pkt->pay.len < sizeof(*pkt->udp)) return;
mkpay(pkt, pkt->udp + 1);
MG_DEBUG(("UDP %M:%hu -> %M:%hu len %u", mg_print_ip4, &pkt->ip->src,
mg_ntohs(pkt->udp->sport), mg_print_ip4, &pkt->ip->dst,
mg_ntohs(pkt->udp->dport), (int) pkt->pay.len));
if (pkt->udp->dport == mg_htons(68)) {
pkt->dhcp = (struct dhcp *) (pkt->udp + 1);
mkpay(pkt, pkt->dhcp + 1);
rx_dhcp_client(ifp, pkt);
} else if (ifp->enable_dhcp_server && pkt->udp->dport == mg_htons(67)) {
pkt->dhcp = (struct dhcp *) (pkt->udp + 1);
mkpay(pkt, pkt->dhcp + 1);
rx_dhcp_server(ifp, pkt);
} else {
rx_udp(ifp, pkt);
}
} else if (pkt->ip->proto == 6) {
pkt->tcp = (struct tcp *) (pkt->ip + 1);
if (pkt->pay.len < sizeof(*pkt->tcp)) return;
mkpay(pkt, pkt->tcp + 1);
uint16_t iplen = mg_ntohs(pkt->ip->len);
uint16_t off = (uint16_t) (sizeof(*pkt->ip) + ((pkt->tcp->off >> 4) * 4U));
if (iplen >= off) pkt->pay.len = (size_t) (iplen - off);
MG_DEBUG(("TCP %M:%hu -> %M:%hu len %u", mg_print_ip4, &pkt->ip->src,
mg_ntohs(pkt->tcp->sport), mg_print_ip4, &pkt->ip->dst,
mg_ntohs(pkt->tcp->dport), (int) pkt->pay.len));
rx_tcp(ifp, pkt);
}
}
static void rx_ip6(struct mip_if *ifp, struct pkt *pkt) {
// MG_DEBUG(("IP %d", (int) len));
if (pkt->ip6->proto == 1 || pkt->ip6->proto == 58) {
pkt->icmp = (struct icmp *) (pkt->ip6 + 1);
if (pkt->pay.len < sizeof(*pkt->icmp)) return;
mkpay(pkt, pkt->icmp + 1);
rx_icmp(ifp, pkt);
} else if (pkt->ip6->proto == 17) {
pkt->udp = (struct udp *) (pkt->ip6 + 1);
if (pkt->pay.len < sizeof(*pkt->udp)) return;
// MG_DEBUG((" UDP %u %u -> %u", len, mg_htons(udp->sport),
// mg_htons(udp->dport)));
mkpay(pkt, pkt->udp + 1);
}
}
static void mip_rx(struct mip_if *ifp, void *buf, size_t len) {
const uint8_t broadcast[] = {255, 255, 255, 255, 255, 255};
struct pkt pkt;
memset(&pkt, 0, sizeof(pkt));
pkt.raw.ptr = (char *) buf;
pkt.raw.len = len;
pkt.eth = (struct eth *) buf;
if (pkt.raw.len < sizeof(*pkt.eth)) return; // Truncated - runt?
if (memcmp(pkt.eth->dst, ifp->mac, sizeof(pkt.eth->dst)) != 0 &&
memcmp(pkt.eth->dst, broadcast, sizeof(pkt.eth->dst)) != 0) {
// Not for us. Drop silently
} else if (pkt.eth->type == mg_htons(0x806)) {
pkt.arp = (struct arp *) (pkt.eth + 1);
if (sizeof(*pkt.eth) + sizeof(*pkt.arp) > pkt.raw.len) return; // Truncated
rx_arp(ifp, &pkt);
} else if (pkt.eth->type == mg_htons(0x86dd)) {
pkt.ip6 = (struct ip6 *) (pkt.eth + 1);
if (pkt.raw.len < sizeof(*pkt.eth) + sizeof(*pkt.ip6)) return; // Truncated
if ((pkt.ip6->ver >> 4) != 0x6) return; // Not IP
mkpay(&pkt, pkt.ip6 + 1);
rx_ip6(ifp, &pkt);
} else if (pkt.eth->type == mg_htons(0x800)) {
pkt.ip = (struct ip *) (pkt.eth + 1);
if (pkt.raw.len < sizeof(*pkt.eth) + sizeof(*pkt.ip)) return; // Truncated
// Truncate frame to what IP header tells us
if ((size_t) mg_ntohs(pkt.ip->len) + sizeof(struct eth) < pkt.raw.len) {
pkt.raw.len = (size_t) mg_ntohs(pkt.ip->len) + sizeof(struct eth);
}
if (pkt.raw.len < sizeof(*pkt.eth) + sizeof(*pkt.ip)) return; // Truncated
if ((pkt.ip->ver >> 4) != 4) return; // Not IP
mkpay(&pkt, pkt.ip + 1);
rx_ip(ifp, &pkt);
} else {
MG_DEBUG((" Unknown eth type %x", mg_htons(pkt.eth->type)));
}
}
static void mip_poll(struct mip_if *ifp, uint64_t uptime_ms) {
if (ifp == NULL || ifp->driver == NULL) return;
bool expired_1000ms = mg_timer_expired(&ifp->timer_1000ms, 1000, uptime_ms);
ifp->now = uptime_ms;
// Handle physical interface up/down status
if (expired_1000ms && ifp->driver->up) {
bool up = ifp->driver->up(ifp);
bool current = ifp->state != MIP_STATE_DOWN;
if (up != current) {
ifp->state = up == false ? MIP_STATE_DOWN
: ifp->enable_dhcp_client ? MIP_STATE_UP
: MIP_STATE_READY;
if (!up && ifp->enable_dhcp_client) ifp->ip = 0;
onstatechange(ifp);
}
}
if (ifp->state == MIP_STATE_DOWN) return;
// If IP not configured, send DHCP
if (ifp->ip == 0 && expired_1000ms) tx_dhcp_discover(ifp);
// Read data from the network
size_t len = ifp->driver->rx((void *) ifp->rx.ptr, ifp->rx.len, ifp);
if (len) {
mip_rx(ifp, (void *) ifp->rx.ptr, len);
}
// Process timeouts
for (struct mg_connection *c = ifp->mgr->conns; c != NULL; c = c->next) {
if (c->is_udp || c->is_listening) continue;
if (c->is_connecting || c->is_resolving) continue;
struct connstate *s = (struct connstate *) (c + 1);
if (uptime_ms > s->timer) {
if (s->ttype == MIP_TTYPE_ACK) {
MG_DEBUG(("%lu ack %x %x", c->id, s->seq, s->ack));
tx_tcp(ifp, s->mac, c->rem.ip, TH_ACK, c->loc.port, c->rem.port,
mg_htonl(s->seq), mg_htonl(s->ack), "", 0);
} else {
if (s->tmiss++ > 2) {
mg_error(c, "keepalive");
} else {
MG_DEBUG(("%lu keepalive", c->id));
tx_tcp(ifp, s->mac, c->rem.ip, TH_ACK, c->loc.port, c->rem.port,
mg_htonl(s->seq - 1), mg_htonl(s->ack), "", 0);
}
}
settmout(c, MIP_TTYPE_KEEPALIVE);
}
}
}
// This function executes in interrupt context, thus it should copy data
// somewhere fast. Note that newlib's malloc is not thread safe, thus use
// our lock-free queue with preallocated buffer to copy data and return asap
void mip_qwrite(void *buf, size_t len, struct mip_if *ifp) {
if (q_write(&ifp->queue, buf, len)) {
ifp->nrecv++;
} else {
ifp->ndrop++;
}
}
size_t mip_qread(void *buf, struct mip_if *ifp) {
return q_read(&ifp->queue, buf);
}
size_t mip_driver_rx(void *buf, size_t len, struct mip_if *ifp) {
return mip_qread((void *) ifp->rx.ptr, ifp);
(void) len, (void) buf;
}
void mip_init(struct mg_mgr *mgr, struct mip_if *ifp) {
// If MAC address is not set, make a random one
if (ifp->mac[0] == 0 && ifp->mac[1] == 0 && ifp->mac[2] == 0 &&
ifp->mac[3] == 0 && ifp->mac[4] == 0 && ifp->mac[5] == 0) {
mg_random(ifp->mac, sizeof(ifp->mac));
ifp->mac[0] &= (uint8_t) ~1; // Clear bit 0. 1st byte is even (unicast)
MG_INFO(("MAC not set. Generated random: %M", mg_print_mac, ifp->mac));
}
if (ifp->driver->init && !ifp->driver->init(ifp)) {
MG_ERROR(("driver init failed"));
} else {
size_t maxpktsize = 1540;
ifp->rx.ptr = (char *) calloc(1, maxpktsize), ifp->rx.len = maxpktsize;
ifp->tx.ptr = (char *) calloc(1, maxpktsize), ifp->tx.len = maxpktsize;
if (ifp->queue.len) ifp->queue.buf = (uint8_t *) calloc(1, ifp->queue.len);
ifp->timer_1000ms = mg_millis();
mgr->priv = ifp;
ifp->mgr = mgr;
mgr->extraconnsize = sizeof(struct connstate);
if (ifp->ip == 0) ifp->enable_dhcp_client = true;
memset(ifp->gwmac, 255, sizeof(ifp->gwmac)); // Set to broadcast
// Randomise initial ephemeral port
uint16_t jitter;
mg_random(&jitter, sizeof(jitter));
ifp->eport = MIP_EPHEMERAL_PORT +
(uint16_t) (jitter % (0xffffu - MIP_EPHEMERAL_PORT));
}
}
void mip_free(struct mip_if *ifp) {
free((char *) ifp->rx.ptr);
free((char *) ifp->tx.ptr);
}
int mg_mkpipe(struct mg_mgr *m, mg_event_handler_t fn, void *d, bool udp) {
(void) m, (void) fn, (void) d, (void) udp;
MG_ERROR(("Not implemented"));
return -1;
}
static void send_syn(struct mg_connection *c) {
struct connstate *s = (struct connstate *) (c + 1);
uint32_t isn = mg_htonl((uint32_t) mg_ntohs(c->loc.port));
struct mip_if *ifp = (struct mip_if *) c->mgr->priv;
tx_tcp(ifp, s->mac, c->rem.ip, TH_SYN, c->loc.port, c->rem.port, isn, 0, NULL,
0);
}
void mg_connect_resolved(struct mg_connection *c) {
struct mip_if *ifp = (struct mip_if *) c->mgr->priv;
c->is_resolving = 0;
if (ifp->eport < MIP_EPHEMERAL_PORT) ifp->eport = MIP_EPHEMERAL_PORT;
c->loc.ip = ifp->ip;
c->loc.port = mg_htons(ifp->eport++);
MG_DEBUG(("%lu %M -> %M", c->id, mg_print_ip_port, &c->loc, mg_print_ip_port,
&c->rem));
mg_call(c, MG_EV_RESOLVE, NULL);
if (((c->rem.ip & ifp->mask) == (ifp->ip & ifp->mask))) {
// If we're in the same LAN, fire an ARP lookup. TODO(cpq): handle this!
MG_DEBUG(("%lu ARP lookup...", c->id));
arp_ask(ifp, c->rem.ip);
c->is_arplooking = 1;
} else {
struct connstate *s = (struct connstate *) (c + 1);
memcpy(s->mac, ifp->gwmac, sizeof(ifp->gwmac));
if (c->is_udp) {
mg_call(c, MG_EV_CONNECT, NULL);
} else {
send_syn(c);
c->is_connecting = 1;
}
}
}
bool mg_open_listener(struct mg_connection *c, const char *url) {
c->loc.port = mg_htons(mg_url_port(url));
return true;
}
static void write_conn(struct mg_connection *c) {
long len = c->is_tls ? mg_tls_send(c, c->send.buf, c->send.len)
: mg_io_send(c, c->send.buf, c->send.len);
if (len > 0) {
mg_iobuf_del(&c->send, 0, (size_t) len);
mg_call(c, MG_EV_WRITE, &len);
}
}
static void close_conn(struct mg_connection *c) {
struct connstate *s = (struct connstate *) (c + 1);
mg_iobuf_free(&s->raw); // For TLS connections, release raw data
if (c->is_udp == false && c->is_listening == false) { // For TCP conns,
struct mip_if *ifp = (struct mip_if *) c->mgr->priv; // send TCP FIN
tx_tcp(ifp, s->mac, c->rem.ip, TH_FIN | TH_ACK, c->loc.port, c->rem.port,
mg_htonl(s->seq), mg_htonl(s->ack), NULL, 0);
}
mg_close_conn(c);
}
static bool can_write(struct mg_connection *c) {
return c->is_connecting == 0 && c->is_resolving == 0 && c->send.len > 0 &&
c->is_tls_hs == 0 && c->is_arplooking == 0;
}
void mg_mgr_poll(struct mg_mgr *mgr, int ms) {
struct mg_connection *c, *tmp;
uint64_t now = mg_millis();
mip_poll((struct mip_if *) mgr->priv, now);
mg_timer_poll(&mgr->timers, now);
for (c = mgr->conns; c != NULL; c = tmp) {
tmp = c->next;
mg_call(c, MG_EV_POLL, &now);
MG_VERBOSE(("%lu .. %c%c%c%c%c", c->id, c->is_tls ? 'T' : 't',
c->is_connecting ? 'C' : 'c', c->is_tls_hs ? 'H' : 'h',
c->is_resolving ? 'R' : 'r', c->is_closing ? 'C' : 'c'));
if (c->is_tls_hs) mg_tls_handshake(c);
if (can_write(c)) write_conn(c);
if (c->is_draining && c->send.len == 0) c->is_closing = 1;
if (c->is_closing) close_conn(c);
}
(void) ms;
}
bool mg_send(struct mg_connection *c, const void *buf, size_t len) {
struct mip_if *ifp = (struct mip_if *) c->mgr->priv;
bool res = false;
if (ifp->ip == 0 || ifp->state != MIP_STATE_READY) {
mg_error(c, "net down");
} else if (c->is_udp) {
struct connstate *s = (struct connstate *) (c + 1);
tx_udp(ifp, s->mac, ifp->ip, c->loc.port, c->rem.ip, c->rem.port, buf, len);
res = true;
} else {
res = mg_iobuf_add(&c->send, c->send.len, buf, len);
}
return res;
}
#endif // MG_ENABLE_MIP
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