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/* |
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* Cisco router simulation platform. |
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* Copyright (c) 2005,2006 Christophe Fillot (cf@utc.fr) |
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* |
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* NetIO Filtering. |
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*/ |
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|
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <stdarg.h> |
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#include <unistd.h> |
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#include <errno.h> |
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#include <signal.h> |
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#include <fcntl.h> |
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#include <ctype.h> |
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#include <time.h> |
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#include <sys/time.h> |
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#include <sys/stat.h> |
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#include <sys/types.h> |
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#include <sys/ioctl.h> |
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#include <sys/socket.h> |
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#include <sys/un.h> |
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#include <sys/wait.h> |
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#include <netinet/in.h> |
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#include <arpa/inet.h> |
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#include <netdb.h> |
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#include <pthread.h> |
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#include <pcap.h> |
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|
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#include "registry.h" |
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#include "net.h" |
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#include "net_io.h" |
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#include "net_io_filter.h" |
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|
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/* Filter list */ |
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static netio_pktfilter_t *pf_list = NULL; |
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|
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/* Find a filter */ |
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netio_pktfilter_t *netio_filter_find(char *name) |
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{ |
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netio_pktfilter_t *pf; |
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|
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for(pf=pf_list;pf;pf=pf->next) |
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if (!strcmp(pf->name,name)) |
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return pf; |
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|
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return NULL; |
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} |
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|
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/* Add a new filter */ |
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int netio_filter_add(netio_pktfilter_t *pf) |
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{ |
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if (netio_filter_find(pf->name) != NULL) |
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return(-1); |
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|
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pf->next = pf_list; |
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pf_list = pf; |
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return(0); |
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} |
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|
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/* Bind a filter to a NIO */ |
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int netio_filter_bind(netio_desc_t *nio,int direction,char *pf_name) |
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{ |
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netio_pktfilter_t *pf; |
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|
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if (!(pf = netio_filter_find(pf_name))) |
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return(-1); |
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|
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if (direction == NETIO_FILTER_DIR_RX) { |
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nio->rx_filter_data = NULL; |
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nio->rx_filter = pf; |
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} else if (direction == NETIO_FILTER_DIR_TX) { |
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nio->tx_filter_data = NULL; |
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nio->tx_filter = pf; |
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} else { |
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nio->both_filter_data = NULL; |
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nio->both_filter = pf; |
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} |
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return(0); |
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} |
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|
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/* Unbind a filter from a NIO */ |
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int netio_filter_unbind(netio_desc_t *nio,int direction) |
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{ |
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netio_pktfilter_t *pf; |
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void **opt; |
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|
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if (direction == NETIO_FILTER_DIR_RX) { |
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opt = &nio->rx_filter_data; |
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pf = nio->rx_filter; |
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} else if (direction == NETIO_FILTER_DIR_TX) { |
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opt = &nio->tx_filter_data; |
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pf = nio->tx_filter; |
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} else { |
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opt = &nio->both_filter_data; |
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pf = nio->both_filter; |
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} |
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|
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if (!pf) |
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return(-1); |
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|
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pf->free(nio,opt); |
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return(0); |
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} |
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|
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/* Setup a filter */ |
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int netio_filter_setup(netio_desc_t *nio,int direction,int argc,char *argv[]) |
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{ |
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netio_pktfilter_t *pf; |
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void **opt; |
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|
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if (direction == NETIO_FILTER_DIR_RX) { |
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opt = &nio->rx_filter_data; |
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pf = nio->rx_filter; |
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} else if (direction == NETIO_FILTER_DIR_TX) { |
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opt = &nio->tx_filter_data; |
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pf = nio->tx_filter; |
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} else { |
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opt = &nio->both_filter_data; |
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pf = nio->both_filter; |
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} |
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|
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if (!pf) |
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return(-1); |
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|
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return(pf->setup(nio,opt,argc,argv)); |
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} |
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|
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/* ======================================================================== */ |
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/* Packet Capture ("capture") */ |
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/* GFA */ |
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/* ======================================================================== */ |
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|
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/* Free resources used by filter */ |
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static void pf_capture_free(netio_desc_t *nio,void **opt) |
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{ |
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struct netio_filter_capture *c = *opt; |
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|
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if (c != NULL) { |
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printf("NIO %s: ending packet capture.\n",nio->name); |
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|
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/* Close dumper */ |
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if (c->dumper) |
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pcap_dump_close(c->dumper); |
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|
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/* Close PCAP descriptor */ |
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if (c->desc) |
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pcap_close(c->desc); |
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|
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free(c); |
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*opt = NULL; |
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} |
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} |
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|
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/* Setup filter resources */ |
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static int pf_capture_setup(netio_desc_t *nio,void **opt, |
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int argc,char *argv[]) |
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{ |
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struct netio_filter_capture *c; |
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int link_type; |
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|
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/* We must have a link type and a filename */ |
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if (argc != 2) |
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return(-1); |
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|
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/* Free resources if something has already been done */ |
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pf_capture_free(nio,opt); |
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|
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/* Allocate structure to hold PCAP info */ |
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if (!(c = malloc(sizeof(*c)))) |
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return(-1); |
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|
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if ((link_type = pcap_datalink_name_to_val(argv[0])) == -1) { |
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fprintf(stderr,"NIO %s: unknown link type %s, assuming Ethernet.\n", |
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nio->name,argv[0]); |
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link_type = DLT_EN10MB; |
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} |
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|
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/* Open a dead pcap descriptor */ |
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if (!(c->desc = pcap_open_dead(link_type,8192))) { |
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fprintf(stderr,"NIO %s: pcap_open_dead failure\n",nio->name); |
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goto pcap_open_err; |
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} |
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|
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/* Open the output file */ |
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if (!(c->dumper = pcap_dump_open(c->desc,argv[1]))) { |
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fprintf(stderr,"NIO %s: pcap_dump_open failure (file %s)\n", |
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nio->name,argv[0]); |
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goto pcap_dump_err; |
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} |
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|
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printf("NIO %s: capturing to file '%s'\n",nio->name,argv[1]); |
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*opt = c; |
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return(0); |
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|
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pcap_dump_err: |
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pcap_close(c->desc); |
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pcap_open_err: |
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free(c); |
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return(-1); |
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} |
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|
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/* Packet handler: write packets to a file in CAP format */ |
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static int pf_capture_pkt_handler(netio_desc_t *nio,void *pkt,size_t len, |
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void *opt) |
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{ |
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struct netio_filter_capture *c = opt; |
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struct pcap_pkthdr pkt_hdr; |
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|
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if (c != NULL) { |
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gettimeofday(&pkt_hdr.ts,0); |
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pkt_hdr.caplen = len; |
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pkt_hdr.len = len; |
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|
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pcap_dump((u_char *)c->dumper,&pkt_hdr,pkt); |
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pcap_dump_flush(c->dumper); |
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} |
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|
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return(NETIO_FILTER_ACTION_PASS); |
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} |
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|
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/* Packet capture */ |
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static netio_pktfilter_t pf_capture_def = { |
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"capture", |
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pf_capture_setup, |
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pf_capture_free, |
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pf_capture_pkt_handler, |
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NULL, |
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}; |
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|
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/* ======================================================================== */ |
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/* Frequency Dropping ("freq_drop"). */ |
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/* ======================================================================== */ |
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|
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struct pf_freqdrop_data { |
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int frequency; |
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int current; |
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}; |
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|
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/* Setup filter ressources */ |
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static int pf_freqdrop_setup(netio_desc_t *nio,void **opt, |
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int argc,char *argv[]) |
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{ |
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struct pf_freqdrop_data *data = *opt; |
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|
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if (argc != 1) |
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return(-1); |
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|
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if (!data) { |
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if (!(data = malloc(sizeof(*data)))) |
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return(-1); |
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|
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*opt = data; |
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} |
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|
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data->current = 0; |
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data->frequency = atoi(argv[0]); |
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return(0); |
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} |
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|
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/* Free ressources used by filter */ |
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static void pf_freqdrop_free(netio_desc_t *nio,void **opt) |
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{ |
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if (*opt) |
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free(*opt); |
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|
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*opt = NULL; |
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} |
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|
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/* Packet handler: drop 1 out of n packets */ |
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static int pf_freqdrop_pkt_handler(netio_desc_t *nio,void *pkt,size_t len, |
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void *opt) |
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{ |
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struct pf_freqdrop_data *data = opt; |
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|
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if (data != NULL) { |
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switch(data->frequency) { |
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case -1: |
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return(NETIO_FILTER_ACTION_DROP); |
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case 0: |
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return(NETIO_FILTER_ACTION_PASS); |
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default: |
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data->current++; |
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|
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if (data->current == data->frequency) { |
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data->current = 0; |
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return(NETIO_FILTER_ACTION_DROP); |
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} |
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} |
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} |
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|
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return(NETIO_FILTER_ACTION_PASS); |
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} |
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|
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/* Packet dropping at 1/n frequency */ |
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static netio_pktfilter_t pf_freqdrop_def = { |
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"freq_drop", |
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pf_freqdrop_setup, |
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pf_freqdrop_free, |
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pf_freqdrop_pkt_handler, |
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NULL, |
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}; |
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|
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/* ======================================================================== */ |
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/* Initialization of packet filters. */ |
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/* ======================================================================== */ |
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|
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void netio_filter_load_all(void) |
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{ |
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netio_filter_add(&pf_freqdrop_def); |
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netio_filter_add(&pf_capture_def); |
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} |