toaruos/modules/net.c

903 lines
25 KiB
C

/* vim: tabstop=4 shiftwidth=4 noexpandtab
* This file is part of ToaruOS and is released under the terms
* of the NCSA / University of Illinois License - see LICENSE.md
* Copyright (C) 2014 Kevin Lange
*/
#include <module.h>
#include <logging.h>
#include <hashmap.h>
#include <ipv4.h>
#include <printf.h>
#include <mod/net.h>
#include <mod/shell.h>
static hashmap_t * dns_cache;
// static fs_node_t * irc_socket;
// static uint32_t seq_no = 0xff0000;
// static uint32_t ack_no = 0x0;
static uint8_t mac[6];
static hashmap_t *_tcp_sockets = NULL;
static hashmap_t *_udp_sockets = NULL;
static fs_node_t *_atty = NULL;
static struct netif _netif;
void init_netif_funcs(get_mac_func mac_func, get_packet_func get_func, send_packet_func send_func) {
_netif.get_mac = mac_func;
_netif.get_packet = get_func;
_netif.send_packet = send_func;
memcpy(_netif.hwaddr, _netif.get_mac(), sizeof(_netif.hwaddr));
}
uint32_t ip_aton(const char * in) {
char ip[16];
char * c = ip;
int out[4];
char * i;
memcpy(ip, in, strlen(in) < 15 ? strlen(in) + 1 : 15);
ip[15] = '\0';
i = (char *)lfind(c, '.');
*i = '\0';
out[0] = atoi(c);
c += strlen(c) + 1;
i = (char *)lfind(c, '.');
*i = '\0';
out[1] = atoi(c);
c += strlen(c) + 1;
i = (char *)lfind(c, '.');
*i = '\0';
out[2] = atoi(c);
c += strlen(c) + 1;
out[3] = atoi(c);
return ((out[0] << 24) | (out[1] << 16) | (out[2] << 8) | (out[3]));
}
void ip_ntoa(uint32_t src_addr, char * out) {
sprintf(out, "%d.%d.%d.%d",
(src_addr & 0xFF000000) >> 24,
(src_addr & 0xFF0000) >> 16,
(src_addr & 0xFF00) >> 8,
(src_addr & 0xFF));
}
uint16_t calculate_ipv4_checksum(struct ipv4_packet * p) {
uint32_t sum = 0;
uint16_t * s = (uint16_t *)p;
/* TODO: Checksums for options? */
for (int i = 0; i < 10; ++i) {
sum += ntohs(s[i]);
}
if (sum > 0xFFFF) {
sum = (sum >> 16) + (sum & 0xFFFF);
}
return ~(sum & 0xFFFF) & 0xFFFF;
}
uint16_t calculate_tcp_checksum(struct tcp_check_header * p, struct tcp_header * h, void * d, size_t payload_size) {
uint32_t sum = 0;
uint16_t * s = (uint16_t *)p;
/* TODO: Checksums for options? */
for (int i = 0; i < 6; ++i) {
sum += ntohs(s[i]);
if (sum > 0xFFFF) {
sum = (sum >> 16) + (sum & 0xFFFF);
}
}
s = (uint16_t *)h;
for (int i = 0; i < 10; ++i) {
sum += ntohs(s[i]);
if (sum > 0xFFFF) {
sum = (sum >> 16) + (sum & 0xFFFF);
}
}
uint16_t d_words = payload_size / 2;
s = (uint16_t *)d;
for (unsigned int i = 0; i < d_words; ++i) {
sum += ntohs(s[i]);
if (sum > 0xFFFF) {
sum = (sum >> 16) + (sum & 0xFFFF);
}
}
if (d_words * 2 != payload_size) {
uint8_t * t = (uint8_t *)d;
uint8_t tmp[2];
tmp[0] = t[d_words * sizeof(uint16_t)];
tmp[1] = 0;
uint16_t * f = (uint16_t *)tmp;
sum += ntohs(f[0]);
if (sum > 0xFFFF) {
sum = (sum >> 16) + (sum & 0xFFFF);
}
}
return ~(sum & 0xFFFF) & 0xFFFF;
}
static struct dirent * readdir_netfs(fs_node_t *node, uint32_t index) {
if (index == 0) {
struct dirent * out = malloc(sizeof(struct dirent));
memset(out, 0x00, sizeof(struct dirent));
out->ino = 0;
strcpy(out->name, ".");
return out;
}
if (index == 1) {
struct dirent * out = malloc(sizeof(struct dirent));
memset(out, 0x00, sizeof(struct dirent));
out->ino = 0;
strcpy(out->name, "..");
return out;
}
index -= 2;
return NULL;
}
size_t print_dns_name(fs_node_t * tty, struct dns_packet * dns, size_t offset) {
uint8_t * bytes = (uint8_t *)dns;
while (1) {
uint8_t c = bytes[offset];
if (c == 0) {
offset++;
return offset;
} else if (c >= 0xC0) {
uint16_t ref = ((c - 0xC0) << 8) + bytes[offset+1];
print_dns_name(tty, dns, ref);
offset++;
offset++;
return offset;
} else {
for (int i = 0; i < c; ++i) {
fprintf(tty,"%c",bytes[offset+1+i]);
}
fprintf(tty,".");
offset += c + 1;
}
}
}
static int is_ip(char * name) {
unsigned int dot_count = 0;
unsigned int t = 0;
for (char * c = name; *c != '\0'; ++c) {
if ((*c < '0' || *c > '9') && (*c != '.')) return 0;
if (*c == '.') {
if (t > 255) return 0;
dot_count++;
t = 0;
} else {
t *= 10;
t += *c - '0';
}
if (dot_count == 4) return 0;
}
if (dot_count != 3) return 0;
return 1;
}
static uint32_t socket_read(fs_node_t * node, uint32_t offset, uint32_t size, uint8_t * buffer) {
/* Sleep until we have something to receive */
return 0;
}
static uint32_t socket_write(fs_node_t * node, uint32_t offset, uint32_t size, uint8_t * buffer) {
/* Add the packet to the appropriate interface queue and send it off. */
/* What other things (routing) should we be doing here? Or do we do those somewhere else? */
/* Whatever... */
return 0;
}
uint16_t next_ephemeral_port(void) {
static uint16_t next = 49152;
if (next == 0) {
assert(0 && "All out of ephemeral ports, halting this time.");
}
uint16_t out = next;
next++;
if (next == 0) {
debug_print(WARNING, "Ran out of ephemeral ports - next time I'm going to bail.");
debug_print(WARNING, "You really need to implement a bitmap here.");
}
return out;
}
fs_node_t * socket_ipv4_tcp_create(uint32_t dest, uint16_t target_port, uint16_t source_port) {
/* Okay, first step is to get us added to the table so we can receive syns. */
return NULL;
}
/* TODO: socket_close - TCP close; UDP... just clean us up */
/* TODO: socket_open - idk, whatever */
static fs_node_t * finddir_netfs(fs_node_t * node, char * name) {
/* Should essentially find anything. */
debug_print(WARNING, "Need to look up domain or check if is IP: %s", name);
/* Block until lookup is complete */
if (is_ip(name)) {
debug_print(WARNING, " IP: %x", ip_aton(name));
} else {
if (hashmap_has(dns_cache, name)) {
uint32_t ip = ip_aton(hashmap_get(dns_cache, name));
debug_print(WARNING, " In Cache: %s → %x", name, ip);
} else {
debug_print(WARNING, " Still needs look up.");
}
}
return NULL;
}
static size_t write_dns_packet(uint8_t * buffer, size_t queries_len, uint8_t * queries) {
size_t offset = 0;
size_t payload_size = sizeof(struct dns_packet) + queries_len;
/* Then, let's write an ethernet frame */
struct ethernet_packet eth_out = {
.source = { mac[0], mac[1], mac[2], mac[3], mac[4], mac[5] },
.destination = BROADCAST_MAC,
.type = htons(0x0800),
};
memcpy(&buffer[offset], &eth_out, sizeof(struct ethernet_packet));
offset += sizeof(struct ethernet_packet);
/* Prepare the IPv4 header */
uint16_t _length = htons(sizeof(struct ipv4_packet) + sizeof(struct udp_packet) + payload_size);
uint16_t _ident = htons(1);
struct ipv4_packet ipv4_out = {
.version_ihl = ((0x4 << 4) | (0x5 << 0)), /* 4 = ipv4, 5 = no options */
.dscp_ecn = 0, /* not setting either of those */
.length = _length,
.ident = _ident,
.flags_fragment = 0,
.ttl = 0x40,
.protocol = IPV4_PROT_UDP,
.checksum = 0, /* fill this in later */
.source = htonl(ip_aton("10.0.2.15")),
.destination = htonl(ip_aton("10.0.2.3")),
};
uint16_t checksum = calculate_ipv4_checksum(&ipv4_out);
ipv4_out.checksum = htons(checksum);
memcpy(&buffer[offset], &ipv4_out, sizeof(struct ipv4_packet));
offset += sizeof(struct ipv4_packet);
uint16_t _udp_source = htons(50053); /* Use an ephemeral port */
uint16_t _udp_destination = htons(53);
uint16_t _udp_length = htons(sizeof(struct udp_packet) + payload_size);
/* Now let's build a UDP packet */
struct udp_packet udp_out = {
.source_port = _udp_source,
.destination_port = _udp_destination,
.length = _udp_length,
.checksum = 0,
};
/* XXX calculate checksum here */
memcpy(&buffer[offset], &udp_out, sizeof(struct udp_packet));
offset += sizeof(struct udp_packet);
/* DNS header */
struct dns_packet dns_out = {
.qid = htons(0),
.flags = htons(0x0100), /* Standard query */
.questions = htons(1), /* 1 question */
.answers = htons(0),
.authorities = htons(0),
.additional = htons(0),
};
memcpy(&buffer[offset], &dns_out, sizeof(struct dns_packet));
offset += sizeof(struct dns_packet);
memcpy(&buffer[offset], queries, queries_len);
offset += queries_len;
return offset;
}
static int net_send_ether(struct socket *socket, struct netif* netif, uint16_t ether_type, void* payload, uint32_t payload_size) {
struct ethernet_packet *eth = malloc(sizeof(struct ethernet_packet) + payload_size);
memcpy(eth->source, netif->hwaddr, sizeof(eth->source));
memset(eth->destination, 0xFF, sizeof(eth->destination));
eth->type = htons(ether_type);
if (payload_size) {
memcpy(eth->payload, payload, payload_size);
}
netif->send_packet((uint8_t*)eth, sizeof(struct ethernet_packet) + payload_size);
return 1; // yolo
}
static int net_send_ip(struct socket *socket, int proto, void* payload, uint32_t payload_size) {
struct ipv4_packet *ipv4 = malloc(sizeof(struct ipv4_packet) + payload_size);
uint16_t _length = htons(sizeof(struct ipv4_packet) + payload_size);
uint16_t _ident = htons(1);
ipv4->version_ihl = ((0x4 << 4) | (0x5 << 0)); /* 4 = ipv4, 5 = no options */
ipv4->dscp_ecn = 0; /* not setting either of those */
ipv4->length = _length;
ipv4->ident = _ident;
ipv4->flags_fragment = 0;
ipv4->ttl = 0x40;
ipv4->protocol = proto;
ipv4->checksum = 0; // Fill in later */
ipv4->source = htonl(ip_aton("10.0.2.15")),
ipv4->destination = htonl(socket->ip);
uint16_t checksum = calculate_ipv4_checksum(ipv4);
ipv4->checksum = htons(checksum);
if (proto == IPV4_PROT_TCP) {
// Need to calculate TCP checksum
struct tcp_check_header check_hd = {
.source = ipv4->source,
.destination = ipv4->destination,
.zeros = 0,
.protocol = 6,
.tcp_len = htons(payload_size),
};
fprintf(_atty, "net_send_ip: Payload size: %d\n", payload_size);
struct tcp_header* tcp_hdr = (struct tcp_header*)payload;
fprintf(_atty, "net_send_ip: Header len htons: %d\n", TCP_HEADER_LENGTH_FLIPPED(tcp_hdr));
size_t orig_payload_size = payload_size - TCP_HEADER_LENGTH_FLIPPED(tcp_hdr);
uint16_t chk = calculate_tcp_checksum(&check_hd, tcp_hdr, tcp_hdr->payload, orig_payload_size);
tcp_hdr->checksum = htons(chk);
}
if (payload) {
memcpy(ipv4->payload, payload, payload_size);
}
// TODO: netif should not be a global thing. But the route should be looked up here and a netif object created/returned
return net_send_ether(socket, &_netif, ETHERNET_TYPE_IPV4, ipv4, sizeof(struct ipv4_packet) + payload_size);
}
static int net_send_tcp(struct socket *socket, uint16_t flags, uint8_t * payload, uint32_t payload_size) {
struct tcp_header *tcp = malloc(sizeof(struct tcp_header) + payload_size);
tcp->source_port = htons(socket->port_recv);
tcp->destination_port = htons(socket->port_dest);
tcp->seq_number = htonl(socket->proto_sock.tcp_socket.seq_no);
tcp->ack_number = flags & (TCP_FLAGS_ACK) ? htonl(socket->proto_sock.tcp_socket.ack_no) : 0;
tcp->flags = htons(0x5000 ^ (flags & 0xFF));
tcp->window_size = htons(1800);
tcp->checksum = 0; // Fill in later
tcp->urgent = 0;
if ((flags & 0xff) == TCP_FLAGS_SYN) {
// If only SYN set, expected ACK will be 1 despite no payload
socket->proto_sock.tcp_socket.seq_no += 1;
} else {
socket->proto_sock.tcp_socket.seq_no += payload_size;
}
if (payload) {
memcpy(tcp->payload, payload, payload_size);
}
return net_send_ip(socket, IPV4_PROT_TCP, tcp, sizeof(struct tcp_header) + payload_size);
}
struct socket* net_open(uint32_t type) {
// This is a socket() call
struct socket *sock = malloc(sizeof(struct socket));
memset(sock, 0, sizeof(struct socket));
sock->sock_type = type;
return sock;
}
int net_close(struct socket* socket) {
// socket->is_connected;
return 1;
}
int net_send(struct socket* socket, uint8_t* payload, size_t payload_size, int flags) {
return net_send_tcp(socket, TCP_FLAGS_ACK | TCP_FLAGS_PSH, payload, payload_size);
}
size_t net_recv(struct socket* socket, uint8_t* buffer, size_t len) {
tcpdata_t *tcpdata = NULL;
node_t *node = NULL;
fprintf(_atty, "net_recv: ENTER\n");
spin_lock(socket->packet_queue_lock);
fprintf(_atty, "net_recv: Got lock\n");
do {
fprintf(_atty, "net_recv: check length: %d\n", socket->packet_queue->length);
if (socket->packet_queue->length > 0) {
fprintf(_atty, "net_recv: Packet in recv queue\n");
node = list_dequeue(socket->packet_queue);
break;
} else {
fprintf(_atty, "net_recv: Aint got nothin, go to sleep son.\n");
spin_unlock(socket->packet_queue_lock);
sleep_on(socket->packet_wait);
spin_lock(socket->packet_queue_lock);
fprintf(_atty, "net_recv: Annnnnnd we're back\n");
}
} while (1);
fprintf(_atty, "net_recv: About to unlock\n");
spin_unlock(socket->packet_queue_lock);
tcpdata = node->value;
fprintf(_atty, "net_recv: Got packet with len: %d\n", tcpdata->payload_size);
if (tcpdata->payload != 0) {
memcpy(buffer, tcpdata->payload, len < tcpdata->payload_size ? len : tcpdata->payload_size);
}
fprintf(_atty, "net_recv: About to free the node value\n");
free(node->value);
fprintf(_atty, "net_recv: About to free the node\n");
free(node);
return tcpdata->payload_size;
}
static void net_handle_tcp(struct tcp_header * tcp, size_t length) {
fprintf(_atty, "net_handle_tcp: ENTER\n");
size_t data_length = length - TCP_HEADER_LENGTH_FLIPPED(tcp);
fprintf(_atty, "net_handle_tcp: Got src port: %d | dst port: %d\n", ntohs(tcp->source_port), ntohs(tcp->destination_port));
/* Find socket */
if (hashmap_has(_tcp_sockets, (void *)ntohs(tcp->destination_port))) {
struct socket *socket = hashmap_get(_tcp_sockets, (void *)ntohs(tcp->destination_port));
if (socket->proto_sock.tcp_socket.seq_no != ntohl(tcp->ack_number)) {
// Drop packet
fprintf(_atty, "Dropping packet. Expected ack: %d | Got ack: %d\n",
socket->proto_sock.tcp_socket.seq_no, ntohl(tcp->ack_number));
return;
}
if ((htons(tcp->flags) & TCP_FLAGS_SYN) && (htons(tcp->flags) & TCP_FLAGS_ACK)) {
fprintf(_atty, "net_handle_tcp: SYN-ACK data_length: %d\n", data_length);
socket->proto_sock.tcp_socket.ack_no = ntohl(tcp->seq_number) + data_length + 1;
net_send_tcp(socket, TCP_FLAGS_ACK, NULL, 0);
wakeup_queue(socket->proto_sock.tcp_socket.is_connected);
}
else if (htons(tcp->flags) & TCP_FLAGS_RES)
{
fprintf(_atty, "net_handle_tcp: Received RST - socket closing\n");
net_close(socket);
return;
}
else
{
// Store a copy of the layer 5 data for a userspace recv() call
tcpdata_t *tcpdata = malloc(sizeof(tcpdata_t));
tcpdata->payload_size = length - TCP_HEADER_LENGTH_FLIPPED(tcp);
if (tcpdata->payload_size == 0) {
return;
}
fprintf(_atty, "net_handle_tcp: payload length: %d\n", length);
fprintf(_atty, "net_handle_tcp: tcp flags hdr len: %d\n", TCP_HEADER_LENGTH(tcp));
fprintf(_atty, "net_handle_tcp: flipped tcp flags hdr len: %d\n", TCP_HEADER_LENGTH_FLIPPED(tcp));
fprintf(_atty, "net_handle_tcp: tcpdata->payload_size: %d\n", tcpdata->payload_size);
if (tcpdata->payload_size > 0) {
tcpdata->payload = malloc(tcpdata->payload_size);
memcpy(tcpdata->payload, tcp->payload, tcpdata->payload_size);
} else {
tcpdata->payload = NULL;
}
fprintf(_atty, "net_handle_tcp: data_length: %d\n", data_length);
socket->proto_sock.tcp_socket.ack_no = ntohl(tcp->seq_number) + data_length;
fprintf(_atty, "net_handle_tcp: set ack: %d\n", socket->proto_sock.tcp_socket.ack_no);
if ((htons(tcp->flags) & TCP_FLAGS_SYN) && (htons(tcp->flags) & TCP_FLAGS_ACK) && data_length == 0) {
fprintf(_atty, "net_handle_tcp: adding 1 to ack\n");
socket->proto_sock.tcp_socket.ack_no += 1;
}
fprintf(_atty, "net_handle_tcp: set ack: %d\n", socket->proto_sock.tcp_socket.ack_no);
socket->proto_sock.tcp_socket.ack_no = ntohl(tcp->seq_number) + tcpdata->payload_size;
fprintf(_atty, "net_handle_tcp: new ack: %d\n", socket->proto_sock.tcp_socket.ack_no);
spin_lock(socket->packet_queue_lock);
list_insert(socket->packet_queue, tcpdata);
spin_unlock(socket->packet_queue_lock);
wakeup_queue(socket->packet_wait);
}
} else {
fprintf(_atty, "net_handle_tcp: Received packet not associated with a socket!\n");
}
fprintf(_atty, "net_handle_tcp: RETURN\n");
}
static void net_handle_udp(struct udp_packet * udp, size_t length) {
// size_t data_length = length - sizeof(struct tcp_header);
/* Find socket */
if (hashmap_has(_udp_sockets, (void *)ntohs(udp->source_port))) {
/* Do the thing */
} else {
/* ??? */
}
}
static void net_handle_ipv4(struct ipv4_packet * ipv4) {
fprintf(_atty, "net_handle_ipv4: ENTER\n");
switch (ipv4->protocol) {
case IPV4_PROT_TCP:
fprintf(_atty, "net_handle_ipv4: about to handle TCP packet\n");
net_handle_tcp((struct tcp_header *)ipv4->payload, ntohs(ipv4->length) - sizeof(struct ipv4_packet));
break;
case IPV4_PROT_UDP:
net_handle_udp((struct udp_packet *)ipv4->payload, ntohs(ipv4->length) - sizeof(struct ipv4_packet));
break;
default:
/* XXX */
break;
}
fprintf(_atty, "net_handle_ipv4: RETURN\n");
}
static struct ethernet_packet* net_receive(void) {
struct ethernet_packet *eth = _netif.get_packet();
return eth;
}
int net_connect(struct socket* socket, uint32_t dest_ip, uint16_t dest_port) {
if (socket->sock_type == SOCK_DGRAM) {
// Can't connect UDP
return -1;
}
memset(socket->mac, 0, sizeof(socket->mac)); // idk
socket->port_recv = next_ephemeral_port();
socket->proto_sock.tcp_socket.is_connected = list_create();
socket->proto_sock.tcp_socket.seq_no = 0;
socket->proto_sock.tcp_socket.ack_no = 0;
socket->proto_sock.tcp_socket.status = 0;
socket->packet_queue = list_create();
socket->packet_wait = list_create();
socket->ip = dest_ip; //ip_aton("10.255.50.206");
socket->port_dest = dest_port; //12345;
fprintf(_atty, "net_connect: using ephemeral port: %d\n", (void*)socket->port_recv);
hashmap_set(_tcp_sockets, (void*)socket->port_recv, socket);
net_send_tcp(socket, TCP_FLAGS_SYN, NULL, 0);
// fprintf(_atty, "net_connect:sent tcp SYN: %d\n", ret);
// Race condition here - if net_handle_tcp runs and connects before this sleep
sleep_on(socket->proto_sock.tcp_socket.is_connected);
return 1;
}
DEFINE_SHELL_FUNCTION(conn, "Do connection") {
int ret;
fprintf(_atty, "conn: Get socket\n");
struct socket* socket = net_open(SOCK_STREAM);
fprintf(_atty, "conn: Make connection\n");
// ret = net_connect(socket, ip_aton("192.168.134.129"), 12345);
ret = net_connect(socket, ip_aton("10.255.50.206"), 12345);
fprintf(_atty, "conn: connection ret: %d\n", ret);
return 0;
}
void net_handler(void * data, char * name) {
/* Network Packet Handler*/
fs_node_t * tty = data;
_atty = tty;
// char *words = "ello govna";
fprintf(tty, "net_handler: ENTER\n");
_netif.extra = NULL;
// TODO: THIS MUST BE CHANGED
_netif.source = 0x0a0a0a0a; // "10.10.10.10"
_tcp_sockets = hashmap_create_int(0xFF);
_udp_sockets = hashmap_create_int(0xFF);
// fprintf(tty, "net_handler: About to get socket\n");
// struct socket* socket = net_open(SOCK_STREAM);
// fprintf(tty, "net_handler: About to send connect()\n");
// int ret = net_connect(socket);
// fprintf(tty, "net_handler: return from connect(): %d\n", ret);
// ret = net_send(socket, (uint8_t*)words, 11, 0);
// fprintf(tty, "net_handler: return from net_send(): %d\n", ret);
while (1) {
struct ethernet_packet * eth = net_receive();
if (!eth) continue;
switch (ntohs(eth->type)) {
case ETHERNET_TYPE_IPV4:
net_handle_ipv4((struct ipv4_packet *)eth->payload);
break;
case ETHERNET_TYPE_ARP:
// net_handle_arp(eth);
break;
}
free(eth);
}
}
size_t write_dhcp_packet(uint8_t * buffer) {
size_t offset = 0;
size_t payload_size = sizeof(struct dhcp_packet);
/* First, let's figure out how big this is supposed to be... */
uint8_t dhcp_options[] = {
53, /* Message type */
1, /* Length: 1 */
1, /* Discover */
255, /* END */
};
payload_size += sizeof(dhcp_options);
/* Then, let's write an ethernet frame */
struct ethernet_packet eth_out = {
.source = { mac[0], mac[1], mac[2], mac[3], mac[4], mac[5] },
.destination = BROADCAST_MAC,
.type = htons(0x0800),
};
memcpy(&buffer[offset], &eth_out, sizeof(struct ethernet_packet));
offset += sizeof(struct ethernet_packet);
/* Prepare the IPv4 header */
uint16_t _length = htons(sizeof(struct ipv4_packet) + sizeof(struct udp_packet) + payload_size);
uint16_t _ident = htons(1);
struct ipv4_packet ipv4_out = {
.version_ihl = ((0x4 << 4) | (0x5 << 0)), /* 4 = ipv4, 5 = no options */
.dscp_ecn = 0, /* not setting either of those */
.length = _length,
.ident = _ident,
.flags_fragment = 0,
.ttl = 0x40,
.protocol = IPV4_PROT_UDP,
.checksum = 0, /* fill this in later */
.source = htonl(ip_aton("0.0.0.0")),
.destination = htonl(ip_aton("255.255.255.255")),
};
uint16_t checksum = calculate_ipv4_checksum(&ipv4_out);
ipv4_out.checksum = htons(checksum);
memcpy(&buffer[offset], &ipv4_out, sizeof(struct ipv4_packet));
offset += sizeof(struct ipv4_packet);
uint16_t _udp_source = htons(68);
uint16_t _udp_destination = htons(67);
uint16_t _udp_length = htons(sizeof(struct udp_packet) + payload_size);
/* Now let's build a UDP packet */
struct udp_packet udp_out = {
.source_port = _udp_source,
.destination_port = _udp_destination,
.length = _udp_length,
.checksum = 0,
};
/* XXX calculate checksum here */
memcpy(&buffer[offset], &udp_out, sizeof(struct udp_packet));
offset += sizeof(struct udp_packet);
/* BOOTP headers */
struct dhcp_packet bootp_out = {
.op = 1,
.htype = 1,
.hlen = 6, /* mac address... */
.hops = 0,
.xid = htonl(0x1337), /* transaction id */
.secs = 0,
.flags = 0,
.ciaddr = 0x000000,
.yiaddr = 0x000000,
.siaddr = 0x000000,
.giaddr = 0x000000,
.chaddr = {mac[0], mac[1], mac[2], mac[3], mac[4], mac[5], 0x00},
.sname = {0},
.file = {0},
.magic = htonl(DHCP_MAGIC),
};
memcpy(&buffer[offset], &bootp_out, sizeof(struct dhcp_packet));
offset += sizeof(struct dhcp_packet);
memcpy(&buffer[offset], &dhcp_options, sizeof(dhcp_options));
offset += sizeof(dhcp_options);
return offset;
}
static void parse_dns_response(fs_node_t * tty, void * last_packet) {
struct ethernet_packet * eth = (struct ethernet_packet *)last_packet;
uint16_t eth_type = ntohs(eth->type);
fprintf(tty, "Ethernet II, Src: (%2x:%2x:%2x:%2x:%2x:%2x), Dst: (%2x:%2x:%2x:%2x:%2x:%2x) [type=%4x)\n",
eth->source[0], eth->source[1], eth->source[2],
eth->source[3], eth->source[4], eth->source[5],
eth->destination[0], eth->destination[1], eth->destination[2],
eth->destination[3], eth->destination[4], eth->destination[5],
eth_type);
struct ipv4_packet * ipv4 = (struct ipv4_packet *)eth->payload;
uint32_t src_addr = ntohl(ipv4->source);
uint32_t dst_addr = ntohl(ipv4->destination);
uint16_t length = ntohs(ipv4->length);
char src_ip[16];
char dst_ip[16];
ip_ntoa(src_addr, src_ip);
ip_ntoa(dst_addr, dst_ip);
fprintf(tty, "IP packet [%s → %s] length=%d bytes\n",
src_ip, dst_ip, length);
struct udp_packet * udp = (struct udp_packet *)ipv4->payload;
uint16_t src_port = ntohs(udp->source_port);
uint16_t dst_port = ntohs(udp->destination_port);
uint16_t udp_len = ntohs(udp->length);
fprintf(tty, "UDP [%d → %d] length=%d bytes\n",
src_port, dst_port, udp_len);
struct dns_packet * dns = (struct dns_packet *)udp->payload;
uint16_t dns_questions = ntohs(dns->questions);
uint16_t dns_answers = ntohs(dns->answers);
fprintf(tty, "DNS - %d queries, %d answers\n",
dns_questions, dns_answers);
fprintf(tty, "Queries:\n");
int offset = sizeof(struct dns_packet);
int queries = 0;
uint8_t * bytes = (uint8_t *)dns;
while (queries < dns_questions) {
offset = print_dns_name(tty, dns, offset);
uint16_t * d = (uint16_t *)&bytes[offset];
fprintf(tty, " - Type: %4x %4x\n", ntohs(d[0]), ntohs(d[1]));
offset += 4;
queries++;
}
fprintf(tty, "Answers:\n");
int answers = 0;
while (answers < dns_answers) {
offset = print_dns_name(tty, dns, offset);
uint16_t * d = (uint16_t *)&bytes[offset];
fprintf(tty, " - Type: %4x %4x; ", ntohs(d[0]), ntohs(d[1]));
offset += 4;
uint32_t * t = (uint32_t *)&bytes[offset];
fprintf(tty, "TTL: %d; ", ntohl(t[0]));
offset += 4;
uint16_t * l = (uint16_t *)&bytes[offset];
int _l = ntohs(l[0]);
fprintf(tty, "len: %d; ", _l);
offset += 2;
if (_l == 4) {
uint32_t * i = (uint32_t *)&bytes[offset];
char ip[16];
ip_ntoa(ntohl(i[0]), ip);
fprintf(tty, " Address: %s\n", ip);
} else {
if (ntohs(d[0]) == 5) {
fprintf(tty, "CNAME: ");
print_dns_name(tty, dns, offset);
fprintf(tty, "\n");
} else {
fprintf(tty, "dunno\n");
}
}
offset += _l;
answers++;
}
}
static fs_node_t * netfs_create(void) {
fs_node_t * fnode = malloc(sizeof(fs_node_t));
memset(fnode, 0x00, sizeof(fs_node_t));
fnode->inode = 0;
strcpy(fnode->name, "net");
fnode->mask = 0555;
fnode->flags = FS_DIRECTORY;
fnode->readdir = readdir_netfs;
fnode->finddir = finddir_netfs;
fnode->nlink = 1;
return fnode;
}
static int init(void) {
BIND_SHELL_FUNCTION(conn);
dns_cache = hashmap_create(10);
hashmap_set(dns_cache, "dakko.us", strdup("104.131.140.26"));
/* /dev/net/{domain|ip}/{protocol}/{port} */
vfs_mount("/dev/net", netfs_create());
return 0;
}
static int fini(void) {
return 0;
}
MODULE_DEF(net, init, fini);
MODULE_DEPENDS(debugshell);