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use netlink api (legacy ioctl frontend)

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mykola2312 2024-12-18 13:30:41 +02:00
parent c526033ad9
commit bab44ceea9
1 changed files with 75 additions and 33 deletions
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108
main.c
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@ -3,8 +3,11 @@
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <net/ethernet.h>
#include <linux/if_packet.h>
@ -38,15 +41,17 @@ struct linkinterface {
uint8_t gateway[ETH_ALEN];
int fd; // raw socket
int if_idx;
};
struct linkinterface* link_parse(const char* if_name, const char* host, const char* gateway) {
struct linkinterface* link_parse(const char* if_name, const char* gateway) {
struct linkinterface* link = (struct linkinterface*)malloc(sizeof(struct linkinterface));
link->if_name = strdup(if_name);
link->if_len = strlen(link->if_name);
parse_mac(host, link->host);
parse_mac(gateway, link->gateway);
return link;
}
int link_open(struct linkinterface* link) {
@ -54,7 +59,25 @@ int link_open(struct linkinterface* link) {
if (link->fd < 0) {
return 1;
}
setsockopt(link->fd, SOL_SOCKET, SO_BINDTODEVICE, link->if_name, link->if_name);
setsockopt(link->fd, SOL_SOCKET, SO_BINDTODEVICE, link->if_name, link->if_len);
// get interface index and MAC
struct ifreq netlink;
memset(&netlink, '\0', sizeof(netlink));
strncpy(netlink.ifr_ifrn.ifrn_name, link->if_name, IFNAMSIZ-1);
if (ioctl(link->fd, SIOCGIFINDEX, &netlink) < 0) {
return 1;
}
link->if_idx = netlink.ifr_ifru.ifru_ivalue; // index
memset(&netlink, '\0', sizeof(netlink));
strncpy(netlink.ifr_ifrn.ifrn_name, link->if_name, IFNAMSIZ-1);
if (ioctl(link->fd, SIOCGIFHWADDR, &netlink) < 0) {
return 1;
}
memcpy(link->host, netlink.ifr_ifru.ifru_hwaddr.sa_data, ETH_ALEN); // MAC
return 0;
}
void link_free(struct linkinterface* link) {
@ -63,24 +86,7 @@ void link_free(struct linkinterface* link) {
free(link);
}
typedef struct arp_packet_s {
struct ether_header ether;
uint16_t hrd; // Hardware address space (e.g., Ethernet, Packet Radio Net.)
uint16_t pro; // Protocol address space. For Ethernet hardware, this is from the set of type fields ether_typ$<protocol>.
uint8_t hln; // byte length of each hardware address
uint8_t pln; // byte length of each protocol address
uint16_t op; // opcode (ares_op$REQUEST | ares_op$REPLY)
uint8_t sha[ETH_ALEN]; // Hardware address of sender of this packet
uint8_t spa[4]; // Protocol address of sender of this packet
uint8_t tha[ETH_ALEN]; // Hardware address of sender of this packet
uint8_t tpa[4]; // Protocol address of sender of this packet
} __attribute__((packed)) arp_packet_t;
#define ARP_OP_REQUEST 0x01
#define ARP_OP_REPLY 0x02
int link_send(struct linkinterface* link, uint16_t type, uint8_t* packet, size_t len) {
ssize_t link_send(struct linkinterface* link, uint16_t type, uint8_t* packet, size_t len) {
struct ether_header* ether = (struct ether_header*)packet;
memcpy(ether->ether_shost, link->host, ETH_ALEN);
memcpy(ether->ether_dhost, link->gateway, ETH_ALEN);
@ -89,7 +95,7 @@ int link_send(struct linkinterface* link, uint16_t type, uint8_t* packet, size_t
return send(link->fd, packet, len, 0);
}
int link_recv(struct linkinterface* link, uint16_t type, uint8_t* packet, size_t len) {
ssize_t link_recv(struct linkinterface* link, uint16_t type, uint8_t* packet, size_t len) {
char buffer[MTU];
uint16_t want_type = htons(type);
do {
@ -117,23 +123,59 @@ int link_recv(struct linkinterface* link, uint16_t type, uint8_t* packet, size_t
// TODO: timeout
}
#define ARP_HW_ETHER 0x000F
#define ARP_PT_IP 0x0800
#define ARP_OP_REQUEST 1
#define ARP_OP_REPLY 2
// Inverse ARP
#define INARP_OP_REQUEST 8
#define INART_OP_REPLY 9
typedef struct arp_packet_s {
struct ether_header ether;
uint16_t hrd; // Hardware address space (e.g., Ethernet, Packet Radio Net.)
uint16_t pro; // Protocol address space. For Ethernet hardware, this is from the set of type fields ether_typ$<protocol>.
uint8_t hln; // byte length of each hardware address
uint8_t pln; // byte length of each protocol address
uint16_t op; // opcode (ares_op$REQUEST | ares_op$REPLY)
uint8_t sha[ETH_ALEN]; // Hardware address of sender of this packet
uint8_t spa[4]; // Protocol address of sender of this packet
uint8_t tha[ETH_ALEN]; // Hardware address of sender of this packet
uint8_t tpa[4]; // Protocol address of sender of this packet
} __attribute__((packed)) arp_packet_t;
int main(int argc, char** argv) {
// ifname hostMAC gatewayMAC targetMAC
struct linkinterface* link = link_parse(argv[1], argv[2], argv[3]);
struct linkinterface* link = link_parse(argv[1], argv[2]);
uint8_t target[ETH_ALEN];
parse_mac(argv[4], target);
parse_mac(argv[3], target);
link_open(link);
// test receive
while (1) {
uint8_t packet[MTU];
ssize_t rd = recv(link->fd, packet, MTU, 0);
struct ether_header *ether = (struct ether_header *)&packet[0];
print_mac(ether->ether_shost);
if (link_open(link) < 0) {
perror("link_open");
return 1;
}
print_mac(link->host);
uint8_t ip[4] = {192, 168, 100, 3};
// test arp send
arp_packet_t arp;
arp.hrd = htons(ARP_HW_ETHER);
arp.pro = htons(ARP_PT_IP);
arp.hln = htons(ETH_ALEN);
arp.pln = htons(4);
arp.op = htons(INARP_OP_REQUEST);
memcpy(arp.sha, link->host, ETH_ALEN);
memcpy(arp.spa, ip, 4);
memcpy(arp.tha, target, ETH_ALEN);
memset(arp.tpa, '\0', 4);
ssize_t sent = link_send(link, ETHERTYPE_ARP, (uint8_t*)&arp, sizeof(arp));
printf("sent %ld\n", sent);
link_free(link);
return 0;