master

分支 (1)

管理

管理

master

tcpip
/
icmpdump.cpp

#include <arpa/inet.h>
#include <errno.h>
#include <iostream>
#include <linux/if_packet.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <netinet/if_ether.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netinet/udp.h>
#include <sstream>
#include <stdexcept>
#include <string.h>
#include <string>
#include <strings.h>
#include <sys/socket.h>
#include <unistd.h>

using namespace std;

#define throw_unix_error(fn) throw runtime_error(string(fn) + ": " + strerror(errno))

struct {
    string iface;
    bool hexdump = false;
} options;

void parse_options(int argc, char *argv[])
{
    for (;;) {
        int c = getopt(argc, argv, ":i:x");
        switch (c) {
        case -1:
            return;
        case 'i':
            options.iface = optarg;
            break;
        case 'x':
            options.hexdump = true;
            break;
        default:
            throw invalid_argument(string{(char)c});
        }
    }
}

struct __attribute__((__packed__)) myicmp {
    struct ethhdr eth_hdr;
    struct iphdr ip_hdr;
    struct icmp icmp;
    /* 假设没有ip选项*/
    union {
        struct udphdr udp_hdr;
    };
};

struct ipaddr {
    in_addr_t in_addr;
};

ostream &operator<<(ostream &out, const ipaddr &ip)
{
    struct in_addr in;
    in.s_addr = ip.in_addr;
    out << inet_ntoa(in);
    return out;
}

ostream &operator<<(ostream &out, const struct iphdr &ip_hdr)
{
    out << "IP " << ipaddr{ip_hdr.saddr} << " > " << ipaddr{ip_hdr.daddr};
    return out;
}

inline int icmp_len(const myicmp *icmp)
{
    return ntohs(icmp->ip_hdr.tot_len) - (icmp->ip_hdr.ihl << 2);
}

struct midnight {
    unsigned long ms;
};

ostream &operator<<(ostream &out, const midnight &mn)
{
    unsigned long ms = mn.ms % 1000UL;
    unsigned long sec = mn.ms / 1000UL;
    char buf[32];

    sprintf(buf, "%02lu:%02lu:%02lu.%03lu",
            sec / 60 / 60,
            sec / 60 % 60,
            sec % 60,
            ms);
    out << buf;
    return out;
}

template <int type, int code = 0>
struct outicmp {
    const myicmp *icmp;
};

template <int type, int code>
ostream &operator<<(ostream &out, const outicmp<type, code> &icmp)
{
    out << "TODO";
    return out;
}

ostream &operator<<(ostream &out, const outicmp<ICMP_DEST_UNREACH, ICMP_NET_UNREACH> &icmp)
{
    out << icmp.icmp->ip_hdr
        << ": ICMP net " << ipaddr{icmp.icmp->icmp.icmp_ip.ip_dst.s_addr} << " unreachable"
        << ", length " << icmp_len(icmp.icmp);
    return out;
}

ostream &operator<<(ostream &out, const outicmp<ICMP_DEST_UNREACH, ICMP_HOST_UNREACH> &icmp)
{
    out << icmp.icmp->ip_hdr
        << ": ICMP host " << ipaddr{icmp.icmp->icmp.icmp_ip.ip_dst.s_addr} << " unreachable"
        << ", length " << icmp_len(icmp.icmp);
    return out;
}

ostream &operator<<(ostream &out, const outicmp<ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED> &icmp)
{
    out << icmp.icmp->ip_hdr
        << ": ICMP " << ipaddr{icmp.icmp->icmp.icmp_ip.ip_dst.s_addr}
        << " unreachable - need to frag (mtu " << ntohs(icmp.icmp->icmp.icmp_nextmtu) << ")"
        << ", length " << icmp_len(icmp.icmp);
    return out;
}

ostream &operator<<(ostream &out, const outicmp<ICMP_REDIRECT, ICMP_REDIR_HOST> &icmp)
{
    out << icmp.icmp->ip_hdr
        << ": ICMP redirect " << ipaddr{icmp.icmp->icmp.icmp_ip.ip_dst.s_addr}
        << " to host " << ipaddr{icmp.icmp->icmp.icmp_gwaddr.s_addr}
        << ", length " << icmp_len(icmp.icmp);
    return out;
}

ostream &operator<<(ostream &out, const outicmp<ICMP_ECHO> &icmp)
{
    out << icmp.icmp->ip_hdr
        << ": ICMP echo query"
        << ", id " << ntohs(icmp.icmp->icmp.icmp_id)
        << ", seq " << ntohs(icmp.icmp->icmp.icmp_seq)
        << ", length " << icmp_len(icmp.icmp);
    return out;
}

ostream &operator<<(ostream &out, const outicmp<ICMP_ECHOREPLY> &icmp)
{
    out << icmp.icmp->ip_hdr
        << ": ICMP echo reply"
        << ", id " << ntohs(icmp.icmp->icmp.icmp_id)
        << ", seq " << ntohs(icmp.icmp->icmp.icmp_seq)
        << ", length " << icmp_len(icmp.icmp);
    return out;
}

ostream &operator<<(ostream &out, const outicmp<ICMP_TIMESTAMP> &icmp)
{
    out << icmp.icmp->ip_hdr
        << ": ICMP time stamp query"
        << ", id " << ntohs(icmp.icmp->icmp.icmp_id)
        << ", seq " << ntohs(icmp.icmp->icmp.icmp_seq)
        << ", length " << icmp_len(icmp.icmp);
    return out;
}

ostream &operator<<(ostream &out, const outicmp<ICMP_TIMESTAMPREPLY> &icmp)
{
    out << icmp.icmp->ip_hdr
        << ": ICMP time stamp reply"
        << ", id " << ntohs(icmp.icmp->icmp.icmp_id)
        << ", seq " << ntohs(icmp.icmp->icmp.icmp_seq)
        << ", org " << midnight{ntohl(icmp.icmp->icmp.icmp_otime)}
        << ", recv " << midnight{ntohl(icmp.icmp->icmp.icmp_rtime)}
        << ", xmit " << midnight{ntohl(icmp.icmp->icmp.icmp_ttime)}
        << ", length " << icmp_len(icmp.icmp)
        << endl;
    return out;
}

ostream &operator<<(ostream &out, const outicmp<ICMP_DEST_UNREACH, ICMP_PORT_UNREACH> &icmp)
{
    out << icmp.icmp->ip_hdr
        << ": ICMP " << ipaddr{icmp.icmp->icmp.icmp_ip.ip_dst.s_addr}
        << " udp port " << ntohs(icmp.icmp->udp_hdr.uh_dport) << " unreachable"
        << ", length " << icmp_len(icmp.icmp);
    return out;
}

ostream &operator<<(ostream &out, const outicmp<ICMP_TIME_EXCEEDED, ICMP_EXC_TTL> &icmp)
{
    out << icmp.icmp->ip_hdr
        << ": ICMP time exceeded in-transit"
        << ", length " << icmp_len(icmp.icmp);
    return out;
}

ostream &operator<<(ostream &out, const outicmp<ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME> &icmp)
{
    out << icmp.icmp->ip_hdr
        << ": ICMP ip reassembly time exceeded"
        << ", length " << icmp_len(icmp.icmp);
    return out;
}

void dump_icmp_dest_unreach(const myicmp *icmp)
{
    switch (icmp->icmp.icmp_code) {
    case ICMP_PORT_UNREACH:
        cout << outicmp<ICMP_DEST_UNREACH, ICMP_PORT_UNREACH>{icmp} << endl;
        break;
    case ICMP_NET_UNREACH:
        cout << outicmp<ICMP_DEST_UNREACH, ICMP_NET_UNREACH>{icmp} << endl;
        break;
    case ICMP_HOST_UNREACH:
        cout << outicmp<ICMP_DEST_UNREACH, ICMP_HOST_UNREACH>{icmp} << endl;
        break;
    case ICMP_FRAG_NEEDED:
        cout << outicmp<ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED>{icmp} << endl;
        break;
    }
}

void dump_icmp_time_exceeded(const myicmp *icmp)
{
    switch (icmp->icmp.icmp_code) {
    case ICMP_EXC_TTL:
        cout << outicmp<ICMP_TIME_EXCEEDED, ICMP_EXC_TTL>{icmp} << endl;
        break;
    case ICMP_EXC_FRAGTIME:
        cout << outicmp<ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME>{icmp} << endl;
        break;
    }
}

void dump_icmp_redirect(const myicmp *icmp)
{
    switch (icmp->icmp.icmp_code) {
    case ICMP_REDIR_HOST:
        cout << outicmp<ICMP_REDIRECT, ICMP_REDIR_HOST>{icmp} << endl;
        break;
    }
}

void hexdump(const unsigned char *ptr, size_t len)
{
    stringstream ss;
    char buf[16];

    for (size_t i = 0; i < len; i += 2) {
        if (i % 16) {
            ss << ' ';
        } else {
            sprintf(buf, "\t0x%04x:  ", (unsigned int)i);
            ss << '\n'
               << buf;
        }
        sprintf(buf, "%02x%02x", ptr[i], ptr[i + 1]);
        ss << buf;
    }
    string s = ss.str();
    if (!s.empty())
        s.erase(s.cbegin());
    cout << s << endl;
}

void icmpdump(const unsigned char *ptr, size_t len)
{
    myicmp *icmp = (myicmp *)ptr;

    if (icmp->eth_hdr.h_proto != htons(ETH_P_IP))
        return;
    if (icmp->ip_hdr.protocol != IPPROTO_ICMP)
        return;

    switch (icmp->icmp.icmp_type) {
    case ICMP_ECHO:
        cout << outicmp<ICMP_ECHO>{icmp} << endl;
        break;
    case ICMP_ECHOREPLY:
        cout << outicmp<ICMP_ECHOREPLY>{icmp} << endl;
        break;
    case ICMP_TIMESTAMP:
        cout << outicmp<ICMP_TIMESTAMP>{icmp} << endl;
        break;
    case ICMP_TIMESTAMPREPLY:
        cout << outicmp<ICMP_TIMESTAMPREPLY>{icmp} << endl;
        break;
    case ICMP_DEST_UNREACH:
        dump_icmp_dest_unreach(icmp);
        break;
    case ICMP_TIME_EXCEEDED:
        dump_icmp_time_exceeded(icmp);
        break;
    case ICMP_REDIRECT:
        dump_icmp_redirect(icmp);
        break;
    }

    if (options.hexdump)
        hexdump(ptr, len);
}

void do_listen()
{
    int sockfd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
    if (sockfd < 0)
        throw_unix_error("socket");

    if (!options.iface.empty()) {
        unsigned int iface_idx = if_nametoindex(options.iface.c_str());
        if (iface_idx == 0)
            throw_unix_error("if_nametoindex");
        struct sockaddr_ll addr;
        bzero(&addr, sizeof(addr));
        addr.sll_family = AF_PACKET;
        addr.sll_protocol = htons(ETH_P_ALL);
        addr.sll_ifindex = iface_idx;
        if (bind(sockfd, (struct sockaddr *)&addr, sizeof(addr)) < 0)
            throw_unix_error("bind");
    }

    for (;;) {
        unsigned char buf[1024];
        ssize_t nrecv = recvfrom(sockfd, buf, sizeof(buf), 0, NULL, NULL);
        if (nrecv < 0)
            throw_unix_error("recvfrom");
        icmpdump(buf, nrecv);
    }
}

int main(int argc, char *argv[])
{
    try {
        parse_options(argc, argv);
        do_listen();
    } catch (const runtime_error &e) {
        cout << e.what() << endl;
    } catch (const invalid_argument &e) {
        cout << "usage: " << argv[0] << " [-i interface] [-x]" << endl;
    }
}