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mongoose/mip/mip.c

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#include "mip.h"
#if MG_ENABLE_MIP
#if defined(_MSC_VER) || defined(ARDUINO)
#define _Atomic
#else
#include <stdatomic.h>
#endif
#define MIP_ETHEMERAL_PORT 49152
#define U16(ptr) ((((uint16_t) (ptr)[0]) << 8) | (ptr)[1])
#define PDIFF(a, b) ((size_t) (((char *) (b)) - ((char *) (a))))
#ifndef MIP_ARP_ENTRIES
#define MIP_ARP_ENTRIES 5 // Number of ARP cache entries. Maximum 21
#endif
#ifndef MIP_QSIZE
#define MIP_QSIZE (16 * 1024) // Queue size
#endif
#define MIP_ARP_CS (2 + 12 * MIP_ARP_ENTRIES) // ARP cache size
#define MIP_TCP_KEEPALIVE_MS 45000 // TCP keep-alive period, ms
#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
struct mg_iobuf raw; // For TLS only. Incoming raw data
};
struct str {
uint8_t *buf;
size_t len;
};
// Receive queue - single producer, single consumer queue. Interrupt-based
// drivers copy received frames to the queue in interrupt context. mip_poll()
// function runs in event loop context, reads from the queue
struct queue {
uint8_t *buf;
size_t len;
volatile _Atomic size_t tail, head;
};
// Network interface
struct mip_if {
uint8_t mac[6]; // MAC address. Must be set to a valid MAC
uint32_t ip, mask, gw; // IP address, mask, default gateway. Can be 0
struct str rx; // Output (TX) buffer
struct str tx; // Input (RX) buffer
bool use_dhcp; // Enable DCHP
struct mip_driver *driver; // Low level driver
void *driver_data; // Driver-specific data
struct mg_mgr *mgr; // Mongoose event manager
// Internal state, user can use it but should not change it
uint64_t now; // Current time
uint64_t timer_1000ms; // 1000 ms timer: for DHCP and link state
uint8_t arp_cache[MIP_ARP_CS]; // Each entry is 12 bytes
uint16_t eport; // Next ephemeral port
uint16_t dropped; // Number of dropped frames
uint8_t state; // Current state
#define MIP_STATE_DOWN 0 // Interface is down
#define MIP_STATE_UP 1 // Interface is up
#define MIP_STATE_READY 2 // Interface is up and has IP
struct queue queue; // Receive queue
};
#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 str raw; // Raw packet data
struct 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_space(struct queue *q) {
return q->tail > q->head ? q->tail - q->head : q->tail + (q->len - q->head);
}
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 str mkstr(void *buf, size_t len) {
struct str str = {(uint8_t *) buf, len};
return str;
}
static void mkpay(struct pkt *pkt, void *p) {
pkt->pay = mkstr(p, (size_t) (&pkt->raw.buf[pkt->raw.len] - (uint8_t *) 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);
}
// ARP cache is organised as a doubly linked list. A successful cache lookup
// moves an entry to the head of the list. New entries are added by replacing
// the last entry in the list with a new IP/MAC.
// ARP cache format: | prev | next | Entry0 | Entry1 | .... | EntryN |
// ARP entry format: | prev | next | IP (4bytes) | MAC (6bytes) |
// prev and next are 1-byte offsets in the cache, so cache size is max 256 bytes
// ARP entry size is 12 bytes
static void arp_cache_init(uint8_t *p, int n, int size) {
for (int i = 0; i < n; i++) p[2 + i * size] = (uint8_t) (2 + (i - 1) * size);
for (int i = 0; i < n; i++) p[3 + i * size] = (uint8_t) (2 + (i + 1) * size);
p[0] = p[2] = (uint8_t) (2 + (n - 1) * size);
p[1] = p[3 + (n - 1) * size] = 2;
}
#if 0
static inline void arp_cache_dump(const uint8_t *p) {
MG_INFO(("ARP cache:"));
for (uint8_t i = 0, j = p[1]; i < MIP_ARP_ENTRIES; i++, j = p[j + 1]) {
MG_INFO((" %d.%d.%d.%d -> %x:%x:%x:%x:%x:%x", p[j + 2], p[j + 3], p[j + 4],
p[j + 5], p[j + 6], p[j + 7], p[j + 8], p[j + 9], p[j + 10],
p[j + 11]));
}
}
#endif
static uint8_t *arp_cache_find(struct mip_if *ifp, uint32_t ip) {
uint8_t *p = ifp->arp_cache;
if (ip == 0 || ip == 0xffffffffU) return NULL;
for (uint8_t i = 0, j = p[1]; i < MIP_ARP_ENTRIES; i++, j = p[j + 1]) {
if (memcmp(p + j + 2, &ip, sizeof(ip)) == 0) {
p[1] = j, p[0] = p[j]; // Found entry! Point list head to us
// MG_DEBUG(("ARP find: %#lx @ %x:%x:%x:%x:%x:%x", (long) ip, p[j + 6],
// p[j + 7], p[j + 8], p[j + 9], p[j + 10], p[j + 11]));
return p + j + 6; // And return MAC address
}
}
return NULL;
}
static void arp_cache_add(struct mip_if *ifp, uint32_t ip, uint8_t mac[6]) {
uint8_t *p = ifp->arp_cache;
if (ip == 0 || ip == ~0U) return; // Bad IP
if (arp_cache_find(ifp, ip) != NULL) return; // Already exists, do nothing
memcpy(p + p[0] + 2, &ip, sizeof(ip)); // Replace last entry: IP address
memcpy(p + p[0] + 6, mac, 6); // And MAC address
p[1] = p[0], p[0] = p[p[1]]; // Point list head to us
MG_DEBUG(("ARP cache: added %#lx @ %x:%x:%x:%x:%x:%x", (long) mg_htonl(ip),
mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]));
}
static void arp_ask(struct mip_if *ifp, uint32_t ip) {
struct eth *eth = (struct eth *) ifp->tx.buf;
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));
ifp->driver->tx(eth, PDIFF(eth, arp + 1), ifp->driver_data);
}
static void onstatechange(struct mip_if *ifp) {
if (ifp->state == MIP_STATE_READY) {
char buf[40];
struct mg_addr addr = {.ip = ifp->ip};
MG_INFO(("READY, IP: %s", mg_ntoa(&addr, buf, sizeof(buf))));
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 proto, uint32_t ip_src,
uint32_t ip_dst, size_t plen) {
struct eth *eth = (struct eth *) ifp->tx.buf;
struct ip *ip = (struct ip *) (eth + 1);
uint8_t *mac = arp_cache_find(ifp, ip_dst); // Dst IP in ARP cache ?
if (!mac) mac = arp_cache_find(ifp, ifp->gw); // No, use gateway
if (mac) memcpy(eth->dst, mac, sizeof(eth->dst)); // Found? Use it
if (!mac) memset(eth->dst, 255, sizeof(eth->dst)); // No? Use broadcast
memcpy(eth->src, ifp->mac, sizeof(eth->src)); // TODO(cpq): ARP lookup
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, 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, 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));
ifp->driver->tx(ifp->tx.buf,
sizeof(struct eth) + sizeof(*ip) + sizeof(*udp) + len,
ifp->driver_data);
}
static void tx_dhcp(struct mip_if *ifp, uint32_t src, uint32_t dst,
uint8_t *opts, size_t optslen) {
struct dhcp dhcp = {.op = 1,
.htype = 1,
.hlen = 6,
.ciaddr = src,
.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, src, mg_htons(68), dst, mg_htons(67), &dhcp, sizeof(dhcp));
}
static void tx_dhcp_request(struct mip_if *ifp, uint32_t src, uint32_t 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, &dst, sizeof(dst));
memcpy(opts + 20, &src, sizeof(src));
tx_dhcp(ifp, src, dst, opts, sizeof(opts));
}
static void tx_dhcp_discover(struct mip_if *ifp) {
uint8_t opts[] = {
53, 1, 1, // Type: DHCP discover
55, 2, 1, 3, // Parameters: ip, mask
255 // End of options
};
tx_dhcp(ifp, 0, 0xffffffff, opts, sizeof(opts));
MG_DEBUG(("DHCP discover sent"));
}
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
struct eth *eth = (struct eth *) ifp->tx.buf;
struct arp *arp = (struct arp *) (eth + 1);
MG_DEBUG(("ARP op %d %#x %#x", mg_htons(arp->op), arp->spa, arp->tpa));
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 response: we're %#lx", (long) mg_ntohl(ifp->ip)));
ifp->driver->tx(ifp->tx.buf, PDIFF(eth, arp + 1), ifp->driver_data);
} else if (pkt->arp->op == mg_htons(2)) {
if (memcmp(pkt->arp->tha, ifp->mac, sizeof(pkt->arp->tha)) != 0) return;
// MG_INFO(("ARP RESPONSE"));
arp_cache_add(ifp, pkt->arp->spa, pkt->arp->sha);
}
}
static void rx_icmp(struct mip_if *ifp, struct pkt *pkt) {
// MG_DEBUG(("ICMP %d", (int) len));
if (pkt->icmp->type == 8 && pkt->ip->dst == ifp->ip) {
struct ip *ip = tx_ip(ifp, 1, ifp->ip, pkt->ip->src,
sizeof(struct icmp) + pkt->pay.len);
struct icmp *icmp = (struct icmp *) (ip + 1);
memset(icmp, 0, sizeof(*icmp)); // Important - set csum to 0
memcpy(icmp + 1, pkt->pay.buf, pkt->pay.len);
icmp->csum = ipcsum(icmp, sizeof(*icmp) + pkt->pay.len);
ifp->driver->tx(ifp->tx.buf, PDIFF(ifp->tx.buf, icmp + 1) + pkt->pay.len,
ifp->driver_data);
}
}
static void rx_dhcp(struct mip_if *ifp, struct pkt *pkt) {
uint32_t ip = 0, gw = 0, mask = 0;
uint8_t *p = pkt->dhcp->options, *end = &pkt->raw.buf[pkt->raw.len];
if (end < (uint8_t *) (pkt->dhcp + 1)) return;
// MG_DEBUG(("DHCP %u", (unsigned) pkt->raw.len));
while (p < end && p[0] != 255) {
if (p[0] == 1 && p[1] == sizeof(ifp->mask)) {
memcpy(&mask, p + 2, sizeof(mask));
// MG_DEBUG(("MASK %x", mask));
} else if (p[0] == 3 && p[1] == sizeof(ifp->gw)) {
memcpy(&gw, p + 2, sizeof(gw));
ip = pkt->dhcp->yiaddr;
// MG_DEBUG(("IP %x GW %x", ip, gw));
}
p += p[1] + 2;
}
if (ip && mask && gw && ifp->ip == 0) {
// MG_DEBUG(("DHCP offer ip %#08lx mask %#08lx gw %#08lx", (long) ip,
// (long) mask, (long) gw));
arp_cache_add(ifp, pkt->dhcp->siaddr, ((struct eth *) pkt->raw.buf)->src);
ifp->ip = ip, ifp->gw = gw, ifp->mask = mask;
ifp->state = MIP_STATE_READY;
onstatechange(ifp);
tx_dhcp_request(ifp, ip, pkt->dhcp->siaddr);
}
}
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_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.buf, 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, 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, 6, ifp->ip, dst_ip, sizeof(struct tcp) + len);
struct tcp *tcp = (struct tcp *) (ip + 1);
memset(tcp, 0, sizeof(*tcp));
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 ifp->driver->tx(ifp->tx.buf, PDIFF(ifp->tx.buf, tcp + 1) + len,
ifp->driver_data);
}
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->ip->src, flags, pkt->tcp->dport, pkt->tcp->sport, seq,
mg_htonl(mg_ntohl(pkt->tcp->seq) + delta), buf, len);
}
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);
s->timer = ((struct mip_if *) c->mgr->priv)->now + MIP_TCP_KEEPALIVE_MS;
c->rem.ip = pkt->ip->src;
c->rem.port = pkt->tcp->sport;
MG_DEBUG(("%lu accepted %lx:%hx", c->id, mg_ntohl(c->rem.ip), c->rem.port));
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;
}
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));
}
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, 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_KEEPALIVE) 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;
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 (mg_ntohl(pkt->tcp->seq) != s->ack) {
// TODO(cpq): peer sent us SEQ which we don't expect. Retransmit rather
// than close this connection
mg_error(c, "SEQ != ACK: %x %x", mg_ntohl(pkt->tcp->seq), s->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.buf, pkt->pay.len);
io->len += pkt->pay.len;
// Advance ACK counter and setup a timer to send an ACK back
s->ack = (uint32_t) (mg_htonl(pkt->tcp->seq) + pkt->pay.len);
settmout(c, MIP_TTYPE_ACK);
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 = (struct connstate *) (c + 1);
if (c != NULL && s->ttype == MIP_TTYPE_KEEPALIVE) {
settmout(c, MIP_TTYPE_KEEPALIVE);
}
#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
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) {
#if 0
MG_DEBUG(("%lu %d %lx:%hu -> %lx:%hu", c->id, (int) pkt->raw.len,
mg_ntohl(pkt->ip->src), mg_ntohs(pkt->tcp->sport),
mg_ntohl(pkt->ip->dst), mg_ntohs(pkt->tcp->dport)));
mg_hexdump(pkt->pay.buf, pkt->pay.len);
#endif
read_conn(c, pkt);
} 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_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 {
// MG_DEBUG(("dropped silently.."));
}
}
static void rx_ip(struct mip_if *ifp, struct pkt *pkt) {
// MG_DEBUG(("IP %d", (int) pkt->pay.len));
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;
// MG_DEBUG((" UDP %u %u -> %u", len, mg_htons(udp->sport),
// mg_htons(udp->dport)));
mkpay(pkt, pkt->udp + 1);
if (pkt->udp->dport == mg_htons(68)) {
pkt->dhcp = (struct dhcp *) (pkt->udp + 1);
mkpay(pkt, pkt->dhcp + 1);
rx_dhcp(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);
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->ip->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 = {.raw = {.buf = (uint8_t *) buf, .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
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->driver_data);
bool current = ifp->state != MIP_STATE_DOWN;
if (up != current) {
ifp->state = up == false ? MIP_STATE_DOWN
: ifp->use_dhcp ? MIP_STATE_UP
: MIP_STATE_READY;
if (!up && ifp->use_dhcp) ifp->ip = 0;
onstatechange(ifp);
}
}
if (ifp->state == MIP_STATE_DOWN) return;
// if (expired_1000ms) arp_cache_dump(ifp->arp_cache);
if (ifp->ip == 0 && expired_1000ms) {
tx_dhcp_discover(ifp); // If IP not configured, send DHCP
} else if (ifp->use_dhcp == false && expired_1000ms &&
arp_cache_find(ifp, ifp->gw) == NULL) {
arp_ask(ifp, ifp->gw); // If GW's MAC address in not in ARP cache
}
// Read data from the network
for (;;) {
size_t len = ifp->queue.len > 0 ? q_read(&ifp->queue, ifp->rx.buf)
: ifp->driver->rx(ifp->rx.buf, ifp->rx.len,
ifp->driver_data);
if (len == 0) break;
qp_mark(QP_FRAMEPOPPED, (int) q_space(&ifp->queue));
mip_rx(ifp, ifp->rx.buf, len);
qp_mark(QP_FRAMEDONE, (int) q_space(&ifp->queue));
}
// 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", c->id));
tx_tcp(ifp, c->rem.ip, TH_ACK, c->loc.port, c->rem.port,
mg_htonl(s->seq), mg_htonl(s->ack), "", 0);
} else {
MG_DEBUG(("%lu keepalive", c->id));
tx_tcp(ifp, 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);
}
}
#ifdef MIP_QPROFILE
qp_log();
#endif
}
// 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
static void on_rx(void *buf, size_t len, void *userdata) {
struct mip_if *ifp = (struct mip_if *) userdata;
if (q_write(&ifp->queue, buf, len)) {
qp_mark(QP_FRAMEPUSHED, (int) q_space(&ifp->queue));
} else {
ifp->dropped++;
qp_mark(QP_FRAMEDROPPED, ifp->dropped);
MG_ERROR(("dropped %d", (int) len));
}
}
void mip_init(struct mg_mgr *mgr, struct mip_cfg *ipcfg,
struct mip_driver *driver, void *driver_data) {
if (driver->init && !driver->init(ipcfg->mac, driver_data)) {
MG_ERROR(("driver init failed"));
} else {
size_t maxpktsize = 1518, qlen = driver->setrx ? MIP_QSIZE : 0;
struct mip_if *ifp =
(struct mip_if *) calloc(1, sizeof(*ifp) + 2 * maxpktsize + qlen);
memcpy(ifp->mac, ipcfg->mac, sizeof(ifp->mac));
ifp->use_dhcp = ipcfg->ip == 0;
ifp->ip = ipcfg->ip, ifp->mask = ipcfg->mask, ifp->gw = ipcfg->gw;
ifp->rx.buf = (uint8_t *) (ifp + 1), ifp->rx.len = maxpktsize;
ifp->tx.buf = ifp->rx.buf + maxpktsize, ifp->tx.len = maxpktsize;
ifp->driver = driver;
ifp->driver_data = driver_data;
ifp->mgr = mgr;
ifp->queue.buf = ifp->tx.buf + maxpktsize;
ifp->queue.len = qlen;
ifp->timer_1000ms = mg_millis();
arp_cache_init(ifp->arp_cache, MIP_ARP_ENTRIES, 12);
if (driver->setrx) driver->setrx(on_rx, ifp);
mgr->priv = ifp;
mgr->extraconnsize = sizeof(struct connstate);
#ifdef MIP_QPROFILE
qp_init();
#endif
}
}
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;
}
#if 0
static uint16_t mkeport(void) {
uint16_t a = 0, b = mg_millis() & 0xffffU, c = MIP_ETHEMERAL_PORT;
mg_random(&a, sizeof(a));
c += (a ^ b) % (0xffffU - MIP_ETHEMERAL_PORT);
return c;
}
#endif
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_ETHEMERAL_PORT) ifp->eport = MIP_ETHEMERAL_PORT;
c->loc.ip = ifp->ip;
c->loc.port = mg_htons(ifp->eport++);
MG_DEBUG(("%lu %08lx:%hu->%08lx:%hu", c->id, mg_ntohl(c->loc.ip),
mg_ntohs(c->loc.port), mg_ntohl(c->rem.ip), mg_ntohs(c->rem.port)));
mg_call(c, MG_EV_RESOLVE, NULL);
if (c->is_udp) {
mg_call(c, MG_EV_CONNECT, NULL);
} else {
uint32_t isn = mg_htonl((uint32_t) mg_ntohs(c->loc.port));
tx_tcp(ifp, c->rem.ip, TH_SYN, c->loc.port, c->rem.port, isn, 0, NULL, 0);
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, 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;
}
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;
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) {
tx_udp(ifp, 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;
}
#ifdef MIP_QPROFILE
#pragma pack(push, 1)
struct qpentry {
uint32_t timestamp;
uint16_t type;
uint16_t len;
};
#pragma pack(pop)
static struct queue qp;
// This is called from IRQ and main contexts; two producers, single consumer
// TODO(scaprile): avoid concurrency issues (2 queues ?)
void qp_mark(unsigned int type, int len) {
static bool ovf = false;
static uint16_t irq_ctr = 0, drop_ctr = 0;
struct qpentry e = {.timestamp = (uint32_t) mg_millis(),
.type = (uint16_t) type,
.len = (uint16_t) len};
if (type == QP_IRQTRIGGERED) e.len = ++irq_ctr;
if (ovf) {
e.type = (uint16_t) QP_QUEUEOVF;
e.len = drop_ctr;
}
ovf = !q_write(&qp, &e, sizeof(e));
}
void qp_log(void) {
struct qpentry e;
const char *titles[] = {"IRQ ", "PUSH", "POP ", "DONE", "DROP", "OVFL"};
for (int i = 0; i < 10 && q_read(&qp, &e); i++) {
MG_INFO(("%lx %s %u", e.timestamp, titles[e.type], e.len));
}
}
void qp_init(void) {
qp.len = 500 * (sizeof(size_t) + sizeof(struct qpentry));
qp.buf = calloc(1, qp.len); // THERE IS NO FREE
}
#endif // MIP_QPROFILE
#endif // MG_ENABLE_MIP
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