diff options
Diffstat (limited to 'qemu/roms/ipxe/src/util/hijack.c')
| -rw-r--r-- | qemu/roms/ipxe/src/util/hijack.c | 628 |
1 files changed, 0 insertions, 628 deletions
diff --git a/qemu/roms/ipxe/src/util/hijack.c b/qemu/roms/ipxe/src/util/hijack.c deleted file mode 100644 index ed89592b1..000000000 --- a/qemu/roms/ipxe/src/util/hijack.c +++ /dev/null @@ -1,628 +0,0 @@ -#include <stdio.h> -#include <stdlib.h> -#include <unistd.h> -#include <string.h> -#include <stdarg.h> -#include <errno.h> -#include <fcntl.h> -#include <libgen.h> -#include <signal.h> -#include <net/if.h> -#include <net/ethernet.h> -#include <sys/select.h> -#include <sys/socket.h> -#include <sys/stat.h> -#include <sys/un.h> -#include <syslog.h> -#include <getopt.h> -#include <pcap.h> - -#define SNAPLEN 1600 - -/* - * FIXME: is there a way to detect the version of the libpcap library? - * Version 0.9 has pcap_inject; version 0.8 doesn't, but both report - * their version number as 2.4. - */ -#define HAVE_PCAP_INJECT 0 - -struct hijack { - pcap_t *pcap; - int fd; - int datalink; - int filtered; - unsigned long rx_count; - unsigned long tx_count; -}; - -struct hijack_listener { - struct sockaddr_un sun; - int fd; -}; - -struct hijack_options { - char interface[IF_NAMESIZE]; - int daemonise; -}; - -static int daemonised = 0; - -static int signalled = 0; - -static void flag_signalled ( int signal __attribute__ (( unused )) ) { - signalled = 1; -} - -#if ! HAVE_PCAP_INJECT -/** - * Substitute for pcap_inject(), if this version of libpcap doesn't - * have it. Will almost certainly only work under Linux. - * - */ -int pcap_inject ( pcap_t *pcap, const void *data, size_t len ) { - int fd; - char *errbuf = pcap_geterr ( pcap ); - - fd = pcap_get_selectable_fd ( pcap ); - if ( fd < 0 ) { - snprintf ( errbuf, PCAP_ERRBUF_SIZE, - "could not get file descriptor" ); - return -1; - } - if ( write ( fd, data, len ) != len ) { - snprintf ( errbuf, PCAP_ERRBUF_SIZE, - "could not write data: %s", strerror ( errno ) ); - return -1; - } - return len; -} -#endif /* ! HAVE_PCAP_INJECT */ - -/** - * Log error message - * - */ -static __attribute__ (( format ( printf, 2, 3 ) )) void -logmsg ( int level, const char *format, ... ) { - va_list ap; - - va_start ( ap, format ); - if ( daemonised ) { - vsyslog ( ( LOG_DAEMON | level ), format, ap ); - } else { - vfprintf ( stderr, format, ap ); - } - va_end ( ap ); -} - -/** - * Open pcap device - * - */ -static int hijack_open ( const char *interface, struct hijack *hijack ) { - char errbuf[PCAP_ERRBUF_SIZE]; - - /* Open interface via pcap */ - errbuf[0] = '\0'; - hijack->pcap = pcap_open_live ( interface, SNAPLEN, 1, 0, errbuf ); - if ( ! hijack->pcap ) { - logmsg ( LOG_ERR, "Failed to open %s: %s\n", - interface, errbuf ); - goto err; - } - if ( errbuf[0] ) - logmsg ( LOG_WARNING, "Warning: %s\n", errbuf ); - - /* Set capture interface to non-blocking mode */ - if ( pcap_setnonblock ( hijack->pcap, 1, errbuf ) < 0 ) { - logmsg ( LOG_ERR, "Could not make %s non-blocking: %s\n", - interface, errbuf ); - goto err; - } - - /* Get file descriptor for select() */ - hijack->fd = pcap_get_selectable_fd ( hijack->pcap ); - if ( hijack->fd < 0 ) { - logmsg ( LOG_ERR, "Cannot get selectable file descriptor " - "for %s\n", interface ); - goto err; - } - - /* Get link layer type */ - hijack->datalink = pcap_datalink ( hijack->pcap ); - - return 0; - - err: - if ( hijack->pcap ) - pcap_close ( hijack->pcap ); - return -1; -} - -/** - * Close pcap device - * - */ -static void hijack_close ( struct hijack *hijack ) { - pcap_close ( hijack->pcap ); -} - -/** - * Install filter for hijacked connection - * - */ -static int hijack_install_filter ( struct hijack *hijack, - char *filter ) { - struct bpf_program program; - - /* Compile filter */ - if ( pcap_compile ( hijack->pcap, &program, filter, 1, 0 ) < 0 ) { - logmsg ( LOG_ERR, "could not compile filter \"%s\": %s\n", - filter, pcap_geterr ( hijack->pcap ) ); - goto err_nofree; - } - - /* Install filter */ - if ( pcap_setfilter ( hijack->pcap, &program ) < 0 ) { - logmsg ( LOG_ERR, "could not install filter \"%s\": %s\n", - filter, pcap_geterr ( hijack->pcap ) ); - goto err; - } - - logmsg ( LOG_INFO, "using filter \"%s\"\n", filter ); - - pcap_freecode ( &program ); - return 0; - - err: - pcap_freecode ( &program ); - err_nofree: - return -1; -} - -/** - * Set up filter for hijacked ethernet connection - * - */ -static int hijack_filter_ethernet ( struct hijack *hijack, const char *buf, - size_t len ) { - char filter[55]; /* see format string */ - struct ether_header *ether_header = ( struct ether_header * ) buf; - unsigned char *hwaddr = ether_header->ether_shost; - - if ( len < sizeof ( *ether_header ) ) - return -1; - - snprintf ( filter, sizeof ( filter ), "broadcast or multicast or " - "ether host %02x:%02x:%02x:%02x:%02x:%02x", hwaddr[0], - hwaddr[1], hwaddr[2], hwaddr[3], hwaddr[4], hwaddr[5] ); - - return hijack_install_filter ( hijack, filter ); -} - -/** - * Set up filter for hijacked connection - * - */ -static int hijack_filter ( struct hijack *hijack, const char *buf, - size_t len ) { - switch ( hijack->datalink ) { - case DLT_EN10MB: - return hijack_filter_ethernet ( hijack, buf, len ); - default: - logmsg ( LOG_ERR, "unsupported protocol %s: cannot filter\n", - ( pcap_datalink_val_to_name ( hijack->datalink ) ? - pcap_datalink_val_to_name ( hijack->datalink ) : - "UNKNOWN" ) ); - /* Return success so we don't get called again */ - return 0; - } -} - -/** - * Forward data from hijacker - * - */ -static ssize_t forward_from_hijacker ( struct hijack *hijack, int fd ) { - char buf[SNAPLEN]; - ssize_t len; - - /* Read packet from hijacker */ - len = read ( fd, buf, sizeof ( buf ) ); - if ( len < 0 ) { - logmsg ( LOG_ERR, "read from hijacker failed: %s\n", - strerror ( errno ) ); - return -1; - } - if ( len == 0 ) - return 0; - - /* Set up filter if not already in place */ - if ( ! hijack->filtered ) { - if ( hijack_filter ( hijack, buf, len ) == 0 ) - hijack->filtered = 1; - } - - /* Transmit packet to network */ - if ( pcap_inject ( hijack->pcap, buf, len ) != len ) { - logmsg ( LOG_ERR, "write to hijacked port failed: %s\n", - pcap_geterr ( hijack->pcap ) ); - return -1; - } - - hijack->tx_count++; - return len; -}; - -/** - * Forward data to hijacker - * - */ -static ssize_t forward_to_hijacker ( int fd, struct hijack *hijack ) { - struct pcap_pkthdr *pkt_header; - const unsigned char *pkt_data; - ssize_t len; - - /* Receive packet from network */ - if ( pcap_next_ex ( hijack->pcap, &pkt_header, &pkt_data ) < 0 ) { - logmsg ( LOG_ERR, "read from hijacked port failed: %s\n", - pcap_geterr ( hijack->pcap ) ); - return -1; - } - if ( pkt_header->caplen != pkt_header->len ) { - logmsg ( LOG_ERR, "read partial packet (%d of %d bytes)\n", - pkt_header->caplen, pkt_header->len ); - return -1; - } - if ( pkt_header->caplen == 0 ) - return 0; - len = pkt_header->caplen; - - /* Write packet to hijacker */ - if ( write ( fd, pkt_data, len ) != len ) { - logmsg ( LOG_ERR, "write to hijacker failed: %s\n", - strerror ( errno ) ); - return -1; - } - - hijack->rx_count++; - return len; -}; - - -/** - * Run hijacker - * - */ -static int run_hijacker ( const char *interface, int fd ) { - struct hijack hijack; - fd_set fdset; - int max_fd; - ssize_t len; - - logmsg ( LOG_INFO, "new connection for %s\n", interface ); - - /* Open connection to network */ - memset ( &hijack, 0, sizeof ( hijack ) ); - if ( hijack_open ( interface, &hijack ) < 0 ) - goto err; - - /* Do the forwarding */ - max_fd = ( ( fd > hijack.fd ) ? fd : hijack.fd ); - while ( 1 ) { - /* Wait for available data */ - FD_ZERO ( &fdset ); - FD_SET ( fd, &fdset ); - FD_SET ( hijack.fd, &fdset ); - if ( select ( ( max_fd + 1 ), &fdset, NULL, NULL, 0 ) < 0 ) { - logmsg ( LOG_ERR, "select failed: %s\n", - strerror ( errno ) ); - goto err; - } - if ( FD_ISSET ( fd, &fdset ) ) { - len = forward_from_hijacker ( &hijack, fd ); - if ( len < 0 ) - goto err; - if ( len == 0 ) - break; - } - if ( FD_ISSET ( hijack.fd, &fdset ) ) { - len = forward_to_hijacker ( fd, &hijack ); - if ( len < 0 ) - goto err; - if ( len == 0 ) - break; - } - } - - hijack_close ( &hijack ); - logmsg ( LOG_INFO, "closed connection for %s\n", interface ); - logmsg ( LOG_INFO, "received %ld packets, sent %ld packets\n", - hijack.rx_count, hijack.tx_count ); - - return 0; - - err: - if ( hijack.pcap ) - hijack_close ( &hijack ); - return -1; -} - -/** - * Open listener socket - * - */ -static int open_listener ( const char *interface, - struct hijack_listener *listener ) { - - /* Create socket */ - listener->fd = socket ( PF_UNIX, SOCK_SEQPACKET, 0 ); - if ( listener->fd < 0 ) { - logmsg ( LOG_ERR, "Could not create socket: %s\n", - strerror ( errno ) ); - goto err; - } - - /* Bind to local filename */ - listener->sun.sun_family = AF_UNIX, - snprintf ( listener->sun.sun_path, sizeof ( listener->sun.sun_path ), - "/var/run/hijack-%s", interface ); - if ( bind ( listener->fd, ( struct sockaddr * ) &listener->sun, - sizeof ( listener->sun ) ) < 0 ) { - logmsg ( LOG_ERR, "Could not bind socket to %s: %s\n", - listener->sun.sun_path, strerror ( errno ) ); - goto err; - } - - /* Set as a listening socket */ - if ( listen ( listener->fd, 0 ) < 0 ) { - logmsg ( LOG_ERR, "Could not listen to %s: %s\n", - listener->sun.sun_path, strerror ( errno ) ); - goto err; - } - - return 0; - - err: - if ( listener->fd >= 0 ) - close ( listener->fd ); - return -1; -} - -/** - * Listen on listener socket - * - */ -static int listen_for_hijackers ( struct hijack_listener *listener, - const char *interface ) { - int fd; - pid_t child; - int rc; - - logmsg ( LOG_INFO, "Listening on %s\n", listener->sun.sun_path ); - - while ( ! signalled ) { - /* Accept new connection, interruptibly */ - siginterrupt ( SIGINT, 1 ); - siginterrupt ( SIGHUP, 1 ); - fd = accept ( listener->fd, NULL, 0 ); - siginterrupt ( SIGINT, 0 ); - siginterrupt ( SIGHUP, 0 ); - if ( fd < 0 ) { - if ( errno == EINTR ) { - continue; - } else { - logmsg ( LOG_ERR, "accept failed: %s\n", - strerror ( errno ) ); - goto err; - } - } - - /* Fork child process */ - child = fork(); - if ( child < 0 ) { - logmsg ( LOG_ERR, "fork failed: %s\n", - strerror ( errno ) ); - goto err; - } - if ( child == 0 ) { - /* I am the child; run the hijacker */ - rc = run_hijacker ( interface, fd ); - close ( fd ); - exit ( rc ); - } - - close ( fd ); - } - - logmsg ( LOG_INFO, "Stopped listening on %s\n", - listener->sun.sun_path ); - return 0; - - err: - if ( fd >= 0 ) - close ( fd ); - return -1; -} - -/** - * Close listener socket - * - */ -static void close_listener ( struct hijack_listener *listener ) { - close ( listener->fd ); - unlink ( listener->sun.sun_path ); -} - -/** - * Print usage - * - */ -static void usage ( char **argv ) { - logmsg ( LOG_ERR, - "Usage: %s [options]\n" - "\n" - "Options:\n" - " -h|--help Print this help message\n" - " -i|--interface intf Use specified network interface\n" - " -n|--nodaemon Run in foreground\n", - argv[0] ); -} - -/** - * Parse command-line options - * - */ -static int parse_options ( int argc, char **argv, - struct hijack_options *options ) { - static struct option long_options[] = { - { "interface", 1, NULL, 'i' }, - { "nodaemon", 0, NULL, 'n' }, - { "help", 0, NULL, 'h' }, - { }, - }; - int c; - - /* Set default options */ - memset ( options, 0, sizeof ( *options ) ); - strncpy ( options->interface, "eth0", sizeof ( options->interface ) ); - options->daemonise = 1; - - /* Parse command-line options */ - while ( 1 ) { - int option_index = 0; - - c = getopt_long ( argc, argv, "i:hn", long_options, - &option_index ); - if ( c < 0 ) - break; - - switch ( c ) { - case 'i': - strncpy ( options->interface, optarg, - sizeof ( options->interface ) ); - break; - case 'n': - options->daemonise = 0; - break; - case 'h': - usage( argv ); - return -1; - case '?': - /* Unrecognised option */ - return -1; - default: - logmsg ( LOG_ERR, "Unrecognised option '-%c'\n", c ); - return -1; - } - } - - /* Check there's nothing left over on the command line */ - if ( optind != argc ) { - usage ( argv ); - return -1; - } - - return 0; -} - -/** - * Daemonise - * - */ -static int daemonise ( const char *interface ) { - char pidfile[16 + IF_NAMESIZE + 4]; /* "/var/run/hijack-<intf>.pid" */ - char pid[16]; - int pidlen; - int fd = -1; - - /* Daemonise */ - if ( daemon ( 0, 0 ) < 0 ) { - logmsg ( LOG_ERR, "Could not daemonise: %s\n", - strerror ( errno ) ); - goto err; - } - daemonised = 1; /* Direct messages to syslog now */ - - /* Open pid file */ - snprintf ( pidfile, sizeof ( pidfile ), "/var/run/hijack-%s.pid", - interface ); - fd = open ( pidfile, ( O_WRONLY | O_CREAT | O_TRUNC ), - ( S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH ) ); - if ( fd < 0 ) { - logmsg ( LOG_ERR, "Could not open %s for writing: %s\n", - pidfile, strerror ( errno ) ); - goto err; - } - - /* Write pid to file */ - pidlen = snprintf ( pid, sizeof ( pid ), "%d\n", getpid() ); - if ( write ( fd, pid, pidlen ) != pidlen ) { - logmsg ( LOG_ERR, "Could not write %s: %s\n", - pidfile, strerror ( errno ) ); - goto err; - } - - close ( fd ); - return 0; - - err: - if ( fd >= 0 ) - close ( fd ); - return -1; -} - -int main ( int argc, char **argv ) { - struct hijack_options options; - struct hijack_listener listener; - struct sigaction sa; - - /* Parse command-line options */ - if ( parse_options ( argc, argv, &options ) < 0 ) - exit ( 1 ); - - /* Set up syslog connection */ - openlog ( basename ( argv[0] ), LOG_PID, LOG_DAEMON ); - - /* Set up listening socket */ - if ( open_listener ( options.interface, &listener ) < 0 ) - exit ( 1 ); - - /* Daemonise on demand */ - if ( options.daemonise ) { - if ( daemonise ( options.interface ) < 0 ) - exit ( 1 ); - } - - /* Avoid creating zombies */ - memset ( &sa, 0, sizeof ( sa ) ); - sa.sa_handler = SIG_IGN; - sa.sa_flags = SA_RESTART | SA_NOCLDWAIT; - if ( sigaction ( SIGCHLD, &sa, NULL ) < 0 ) { - logmsg ( LOG_ERR, "Could not set SIGCHLD handler: %s", - strerror ( errno ) ); - exit ( 1 ); - } - - /* Set 'signalled' flag on SIGINT or SIGHUP */ - sa.sa_handler = flag_signalled; - sa.sa_flags = SA_RESTART | SA_RESETHAND; - if ( sigaction ( SIGINT, &sa, NULL ) < 0 ) { - logmsg ( LOG_ERR, "Could not set SIGINT handler: %s", - strerror ( errno ) ); - exit ( 1 ); - } - if ( sigaction ( SIGHUP, &sa, NULL ) < 0 ) { - logmsg ( LOG_ERR, "Could not set SIGHUP handler: %s", - strerror ( errno ) ); - exit ( 1 ); - } - - /* Listen for hijackers */ - if ( listen_for_hijackers ( &listener, options.interface ) < 0 ) - exit ( 1 ); - - close_listener ( &listener ); - - return 0; -} |