diff options
Diffstat (limited to 'util/tap/tap.cc')
| -rw-r--r-- | util/tap/tap.cc | 192 |
1 files changed, 154 insertions, 38 deletions
diff --git a/util/tap/tap.cc b/util/tap/tap.cc index f07d49619..f4d0aadf2 100644 --- a/util/tap/tap.cc +++ b/util/tap/tap.cc @@ -173,7 +173,7 @@ Accept(int fd, bool nodelay) } void -Connect(int fd, const string &host, int port) +Connect(int fd, const std::string &host, int port) { struct sockaddr_in sockaddr; if (::inet_aton(host.c_str(), &sockaddr.sin_addr) == 0) { @@ -193,6 +193,133 @@ Connect(int fd, const string &host, int port) DPRINTF("connected to %s on port %d\n", host, port); } +class Ethernet +{ + protected: + int fd; + + public: + virtual ~Ethernet() {} + + int getfd() const { return fd; } + virtual bool read(const char *&data, int &len) = 0; + virtual bool write(const char *data, int len) = 0; +}; + +class Tap : public Ethernet +{ + private: + char buffer[65536]; + int fd; + + public: + Tap(char *device); + ~Tap(); + virtual bool read(const char *&data, int &len); + virtual bool write(const char *data, int len); +}; + +class PCap : public Ethernet +{ + private: + pcap_t *pcap; + eth_t *ethernet; + + public: + PCap(char *device, char *filter = NULL); + ~PCap(); + virtual bool read(const char *&data, int &len); + virtual bool write(const char *data, int len); +}; + +PCap::PCap(char *device, char *filter) +{ + char errbuf[PCAP_ERRBUF_SIZE]; + memset(errbuf, 0, sizeof errbuf); + pcap = pcap_open_live(device, 1500, 1, -1, errbuf); + if (pcap == NULL) + panic("pcap_open_live failed: %s\n", errbuf); + + if (filter) { + bpf_program program; + bpf_u_int32 localnet, netmask; + if (pcap_lookupnet(device, &localnet, &netmask, errbuf) == -1) { + DPRINTF("pcap_lookupnet failed: %s\n", errbuf); + netmask = 0xffffff00; + } + + if (pcap_compile(pcap, &program, filter, 1, netmask) == -1) + panic("pcap_compile failed, invalid filter:\n%s\n", filter); + + if (pcap_setfilter(pcap, &program) == -1) + panic("pcap_setfilter failed\n"); + } + + ethernet = eth_open(device); + if (!ethernet) + panic("cannot open the ethernet device for writing\n"); + + fd = pcap_fileno(pcap); +} + +PCap::~PCap() +{ + pcap_close(pcap); + eth_close(ethernet); +} + +bool +PCap::read(const char *&data, int &len) +{ + pcap_pkthdr hdr; + data = (const char *)pcap_next(pcap, &hdr); + if (!data) + return false; + + len = hdr.len; + return true; +} + +bool +PCap::write(const char *data, int len) +{ + eth_send(ethernet, data, len); +} + +Tap::Tap(char *device) +{ + fd = open(device, O_RDWR, 0); + if (fd < 0) + panic("could not open %s: %s\n", device, strerror(errno)); +} + +Tap::~Tap() +{ + close(fd); +} + +bool +Tap::read(const char *&data, int &len) +{ + DPRINTF("tap read!\n"); + data = buffer; + len = ::read(fd, buffer, sizeof(buffer)); + if (len < 0) + return false; + + return true; +} + +bool +Tap::write(const char *data, int len) +{ + int result = ::write(fd, data, len); + if (result < 0) + return false; + + return true; +} + int main(int argc, char *argv[]) { @@ -201,13 +328,16 @@ main(int argc, char *argv[]) bool listening = false; char *device = NULL; char *filter = NULL; + Ethernet *tap = NULL; + bool usetap = false; char c; int daemon = false; - string host; + std::string host; + int devfd; program = basename(argv[0]); - while ((c = getopt(argc, argv, "b:df:lp:v")) != -1) { + while ((c = getopt(argc, argv, "b:df:lp:tv")) != -1) { switch (c) { case 'b': bufsize = atoi(optarg); @@ -224,6 +354,9 @@ main(int argc, char *argv[]) case 'p': port = atoi(optarg); break; + case 't': + usetap = true; + break; case 'v': verbose++; break; @@ -268,31 +401,14 @@ main(int argc, char *argv[]) host = *argv; } - char errbuf[PCAP_ERRBUF_SIZE]; - memset(errbuf, 0, sizeof errbuf); - pcap_t *pcap = pcap_open_live(device, 1500, 1, -1, errbuf); - if (pcap == NULL) - panic("pcap_open_live failed: %s\n", errbuf); - - if (filter) { - bpf_program program; - bpf_u_int32 localnet, netmask; - if (pcap_lookupnet(device, &localnet, &netmask, errbuf) == -1) { - DPRINTF("pcap_lookupnet failed: %s\n", errbuf); - netmask = 0xffffff00; - } - - if (pcap_compile(pcap, &program, filter, 1, netmask) == -1) - panic("pcap_compile failed, invalid filter:\n%s\n", filter); - - if (pcap_setfilter(pcap, &program) == -1) - panic("pcap_setfilter failed\n"); + if (usetap) { + if (filter) + panic("-f parameter not valid with a tap device!"); + tap = new Tap(device); + } else { + tap = new PCap(device, filter); } - eth_t *ethernet = eth_open(device); - if (!ethernet) - panic("cannot open the ethernet device for writing\n"); - pollfd pfds[3]; pfds[0].fd = Socket(true); pfds[0].events = POLLIN; @@ -303,7 +419,7 @@ main(int argc, char *argv[]) else Connect(pfds[0].fd, host, port); - pfds[1].fd = pcap_fileno(pcap); + pfds[1].fd = tap->getfd(); pfds[1].events = POLLIN; pfds[1].revents = 0; @@ -341,16 +457,16 @@ main(int argc, char *argv[]) listen_pfd->revents = 0; } + DPRINTF("tap events: %x\n", tap_pfd->revents); if (tap_pfd && tap_pfd->revents) { if (tap_pfd->revents & POLLIN) { - pcap_pkthdr hdr; - const u_char *data = pcap_next(pcap, &hdr); - if (data && client_pfd) { - DPRINTF("Received packet from ethernet len=%d\n", hdr.len); - DDUMP(data, hdr.len); - u_int32_t len = htonl(hdr.len); - write(client_pfd->fd, &len, sizeof(len)); - write(client_pfd->fd, data, hdr.len); + const char *data; int len; + if (tap->read(data, len) && client_pfd) { + DPRINTF("Received packet from ethernet len=%d\n", len); + DDUMP(data, len); + u_int32_t swaplen = htonl(len); + write(client_pfd->fd, &swaplen, sizeof(swaplen)); + write(client_pfd->fd, data, len); } } @@ -379,7 +495,7 @@ main(int argc, char *argv[]) while (data_len != 0 && buffer_offset >= data_len + sizeof(u_int32_t)) { char *data = buffer + sizeof(u_int32_t); - eth_send(ethernet, data, data_len); + tap->write(data, data_len); DPRINTF("Sent packet to ethernet len = %d\n", data_len); DDUMP(data, data_len); @@ -412,8 +528,8 @@ main(int argc, char *argv[]) } delete [] buffer; - pcap_close(pcap); - eth_close(ethernet); + delete tap; + if (listen_pfd) close(listen_pfd->fd); |