1.获取设备列表：
#include "pcap.h" main() { pcap_if_t *alldevs; pcap_if_t *d; int i=0; char errbuf[PCAP_ERRBUF_SIZE]; /* Retrieve the device list from the local machine */ if (pcap_findalldevs_ex(PCAP_SRC_IF_STRING, NULL /* auth is not needed */, &alldevs, errbuf) == -1) { fprintf(stderr,"Error in pcap_findalldevs_ex: %s\n", errbuf); exit(1); } /* Print the list */ for(d= alldevs; d != NULL; d= d->next) { printf("%d. %s", ++i, d->name); if (d->description) printf(" (%s)\n", d->description); else printf(" (No description available)\n"); } if (i == 0) { printf("\nNo interfaces found! Make sure WinPcap is installed.\n"); return; } /* We don't need any more the device list. Free it */ pcap_freealldevs(alldevs); }
2.获取设备详细信息
#include <stdio.h> #include "pcap.h" #ifndef WIN32 #include <sys/socket.h> #include <netinet/in.h> #else #include <winsock.h> #endif // Function prototypes void ifprint(pcap_if_t *d); char *iptos(u_long in); char* ip6tos(struct sockaddr *sockaddr, char *address, int addrlen); int main() { pcap_if_t *alldevs; pcap_if_t *d; char errbuf[PCAP_ERRBUF_SIZE+1]; char source[PCAP_ERRBUF_SIZE+1]; printf("Enter the device you want to list:\n" "rpcap:// ==> lists interfaces in the local machine\n" "rpcap://hostname:port ==> lists interfaces in a remote machine\n" " (rpcapd daemon must be up and running\n" " and it must accept 'null' authentication)\n" "file://foldername ==> lists all pcap files in the give folder\n\n" "Enter your choice: "); fgets(source, PCAP_ERRBUF_SIZE, stdin); source[PCAP_ERRBUF_SIZE] = '\0'; /* Retrieve the interfaces list */ if (pcap_findalldevs_ex(source, NULL, &alldevs, errbuf) == -1) { fprintf(stderr,"Error in pcap_findalldevs: %s\n",errbuf); exit(1); } /* Scan the list printing every entry */ for(d=alldevs;d;d=d->next) { ifprint(d); } pcap_freealldevs(alldevs); return 1; } /* Print all the available information on the given interface */ void ifprint(pcap_if_t *d) { pcap_addr_t *a; char ip6str[128]; /* Name */ printf("%s\n",d->name); /* Description */ if (d->description) printf("\tDescription: %s\n",d->description); /* Loopback Address*/ printf("\tLoopback: %s\n",(d->flags & PCAP_IF_LOOPBACK)?"yes":"no"); /* IP addresses */ for(a=d->addresses;a;a=a->next) { printf("\tAddress Family: #%d\n",a->addr->sa_family); switch(a->addr->sa_family) { case AF_INET: printf("\tAddress Family Name: AF_INET\n"); if (a->addr) printf("\tAddress: %s\n",iptos(((struct sockaddr_in *)a->addr)->sin_addr.s_addr)); if (a->netmask) printf("\tNetmask: %s\n",iptos(((struct sockaddr_in *)a->netmask)->sin_addr.s_addr)); if (a->broadaddr) printf("\tBroadcast Address: %s\n",iptos(((struct sockaddr_in *)a->broadaddr)->sin_addr.s_addr)); if (a->dstaddr) printf("\tDestination Address: %s\n",iptos(((struct sockaddr_in *)a->dstaddr)->sin_addr.s_addr)); break; case AF_INET6: printf("\tAddress Family Name: AF_INET6\n"); if (a->addr) printf("\tAddress: %s\n", ip6tos(a->addr, ip6str, sizeof(ip6str))); break; default: printf("\tAddress Family Name: Unknown\n"); break; } } printf("\n"); } /* From tcptraceroute, convert a numeric IP address to a string */ #define IPTOSBUFFERS 12 char *iptos(u_long in) { static char output[IPTOSBUFFERS][3*4+3+1]; static short which; u_char *p; p = (u_char *)∈ which = (which + 1 == IPTOSBUFFERS ? 0 : which + 1); _snprintf_s(output[which], sizeof(output[which]), sizeof(output[which]),"%d.%d.%d.%d", p[0], p[1], p[2], p[3]); return output[which]; } char* ip6tos(struct sockaddr *sockaddr, char *address, int addrlen) { socklen_t sockaddrlen; #ifdef WIN32 sockaddrlen = sizeof(struct sockaddr_in6); #else sockaddrlen = sizeof(struct sockaddr_storage); #endif if(getnameinfo(sockaddr, sockaddrlen, address, addrlen, NULL, 0, NI_NUMERICHOST) != 0) address = NULL; return addres
3.打开一个适配器并抓取数据包
#include "pcap.h" /* prototype of the packet handler */ void packet_handler(u_char *param, const struct pcap_pkthdr *header, const u_char *pkt_data); int main() { pcap_if_t *alldevs; pcap_if_t *d; int inum; int i=0; pcap_t *adhandle; char errbuf[PCAP_ERRBUF_SIZE]; /* Retrieve the device list on the local machine */ if (pcap_findalldevs_ex(PCAP_SRC_IF_STRING, NULL, &alldevs, errbuf) == -1) { fprintf(stderr,"Error in pcap_findalldevs: %s\n", errbuf); exit(1); } /* Print the list */ for(d=alldevs; d; d=d->next) { printf("%d. %s", ++i, d->name); if (d->description) printf(" (%s)\n", d->description); else printf(" (No description available)\n"); } if(i==0) { printf("\nNo interfaces found! Make sure WinPcap is installed.\n"); return -1; } printf("Enter the interface number (1-%d):",i); scanf_s("%d", &inum); if(inum < 1 || inum > i) { printf("\nInterface number out of range.\n"); /* Free the device list */ pcap_freealldevs(alldevs); return -1; } /* Jump to the selected adapter */ for(d=alldevs, i=0; i< inum-1 ;d=d->next, i++); /* Open the device */ if ( (adhandle= pcap_open(d->name, // name of the device 65536, // portion of the packet to capture // 65536 guarantees that the whole packet will be captured on all the link layers PCAP_OPENFLAG_PROMISCUOUS, // promiscuous mode 1000, // read timeout NULL, // authentication on the remote machine errbuf // error buffer ) ) == NULL) { fprintf(stderr,"\nUnable to open the adapter. %s is not supported by WinPcap\n", d->name); /* Free the device list */ pcap_freealldevs(alldevs); return -1; } printf("\nlistening on %s...\n", d->description); /* At this point, we don't need any more the device list. Free it */ pcap_freealldevs(alldevs); /* start the capture */ pcap_loop(adhandle, 0, packet_handler, NULL); return 0; } /* Callback function invoked by libpcap for every incoming packet */ void packet_handler(u_char *param, const struct pcap_pkthdr *header, const u_char *pkt_data) { struct tm ltime; char timestr[16]; time_t local_tv_sec; /* * unused variables */ (VOID)(param); (VOID)(pkt_data); /* convert the timestamp to readable format */ local_tv_sec = header->ts.tv_sec; localtime_s(<ime, &local_tv_sec); strftime( timestr, sizeof timestr, "%H:%M:%S", <ime); printf("%s,%.6d len:%d\n", timestr, header->ts.tv_usec, header->len); }
4.不使用回调函数抓取数据包
#include "pcap.h" int main() { pcap_if_t *alldevs; pcap_if_t *d; int inum; int i=0; pcap_t *adhandle; int res; char errbuf[PCAP_ERRBUF_SIZE]; struct tm ltime; char timestr[16]; struct pcap_pkthdr *header; const u_char *pkt_data; time_t local_tv_sec; /* Retrieve the device list on the local machine */ if (pcap_findalldevs_ex(PCAP_SRC_IF_STRING, NULL, &alldevs, errbuf) == -1) { fprintf(stderr,"Error in pcap_findalldevs: %s\n", errbuf); exit(1); } /* Print the list */ for(d=alldevs; d; d=d->next) { printf("%d. %s", ++i, d->name); if (d->description) printf(" (%s)\n", d->description); else printf(" (No description available)\n"); } if(i==0) { printf("\nNo interfaces found! Make sure WinPcap is installed.\n"); return -1; } printf("Enter the interface number (1-%d):",i); scanf_s("%d", &inum); if(inum < 1 || inum > i) { printf("\nInterface number out of range.\n"); /* Free the device list */ pcap_freealldevs(alldevs); return -1; } /* Jump to the selected adapter */ for(d=alldevs, i=0; i< inum-1 ;d=d->next, i++); /* Open the device */ if ( (adhandle= pcap_open(d->name, // name of the device 65536, // portion of the packet to capture. // 65536 guarantees that the whole packet will be captured on all the link layers PCAP_OPENFLAG_PROMISCUOUS, // promiscuous mode 1000, // read timeout NULL, // authentication on the remote machine errbuf // error buffer ) ) == NULL) { fprintf(stderr,"\nUnable to open the adapter. %s is not supported by WinPcap\n", d->name); /* Free the device list */ pcap_freealldevs(alldevs); return -1; } printf("\nlistening on %s...\n", d->description); /* At this point, we don't need any more the device list. Free it */ pcap_freealldevs(alldevs); /* Retrieve the packets */ while((res = pcap_next_ex( adhandle, &header, &pkt_data)) >= 0){ if(res == 0) /* Timeout elapsed */ continue; /* convert the timestamp to readable format */ local_tv_sec = header->ts.tv_sec; localtime_s(<ime, &local_tv_sec); strftime( timestr, sizeof timestr, "%H:%M:%S", <ime); printf("%s,%.6d len:%d\n", timestr, header->ts.tv_usec, header->len); } if(res == -1){ printf("Error reading the packets: %s\n", pcap_geterr(adhandle)); return -1; } return 0; }
5.过滤并解析数据包
#include "pcap.h" /* 4 bytes IP address */ typedef struct ip_address{ u_char byte1; u_char byte2; u_char byte3; u_char byte4; }ip_address; /* IPv4 header */ typedef struct ip_header{ u_char ver_ihl; // Version (4 bits) + Internet header length (4 bits) u_char tos; // Type of service u_short tlen; // Total length u_short identification; // Identification u_short flags_fo; // Flags (3 bits) + Fragment offset (13 bits) u_char ttl; // Time to live u_char proto; // Protocol u_short crc; // Header checksum ip_address saddr; // Source address ip_address daddr; // Destination address u_int op_pad; // Option + Padding }ip_header; /* UDP header*/ typedef struct udp_header{ u_short sport; // Source port u_short dport; // Destination port u_short len; // Datagram length u_short crc; // Checksum }udp_header; /* prototype of the packet handler */ void packet_handler(u_char *param, const struct pcap_pkthdr *header, const u_char *pkt_data); int main() { pcap_if_t *alldevs; pcap_if_t *d; int inum; int i=0; pcap_t *adhandle; char errbuf[PCAP_ERRBUF_SIZE]; u_int netmask; char packet_filter[] = "ip and udp"; struct bpf_program fcode; /* Retrieve the device list */ if (pcap_findalldevs_ex(PCAP_SRC_IF_STRING, NULL, &alldevs, errbuf) == -1) { fprintf(stderr,"Error in pcap_findalldevs: %s\n", errbuf); exit(1); } /* Print the list */ for(d=alldevs; d; d=d->next) { printf("%d. %s", ++i, d->name); if (d->description) printf(" (%s)\n", d->description); else printf(" (No description available)\n"); } if(i==0) { printf("\nNo interfaces found! Make sure WinPcap is installed.\n"); return -1; } printf("Enter the interface number (1-%d):",i); scanf_s("%d", &inum); if(inum < 1 || inum > i) { printf("\nInterface number out of range.\n"); /* Free the device list */ pcap_freealldevs(alldevs); return -1; } /* Jump to the selected adapter */ for(d=alldevs, i=0; i< inum-1 ;d=d->next, i++); /* Open the adapter */ if ( (adhandle= pcap_open(d->name, // name of the device 65536, // portion of the packet to capture. // 65536 grants that the whole packet will be captured on all the MACs. PCAP_OPENFLAG_PROMISCUOUS, // promiscuous mode 1000, // read timeout NULL, // remote authentication errbuf // error buffer ) ) == NULL) { fprintf(stderr,"\nUnable to open the adapter. %s is not supported by WinPcap\n"); /* Free the device list */ pcap_freealldevs(alldevs); return -1; } /* Check the link layer. We support only Ethernet for simplicity. */ if(pcap_datalink(adhandle) != DLT_EN10MB) { fprintf(stderr,"\nThis program works only on Ethernet networks.\n"); /* Free the device list */ pcap_freealldevs(alldevs); return -1; } if(d->addresses != NULL) /* Retrieve the mask of the first address of the interface */ netmask=((struct sockaddr_in *)(d->addresses->netmask))->sin_addr.S_un.S_addr; else /* If the interface is without addresses we suppose to be in a C class network */ netmask=0xffffff; //compile the filter if (pcap_compile(adhandle, &fcode, packet_filter, 1, netmask) <0 ) { fprintf(stderr,"\nUnable to compile the packet filter. Check the syntax.\n"); /* Free the device list */ pcap_freealldevs(alldevs); return -1; } //set the filter if (pcap_setfilter(adhandle, &fcode)<0) { fprintf(stderr,"\nError setting the filter.\n"); /* Free the device list */ pcap_freealldevs(alldevs); return -1; } printf("\nlistening on %s...\n", d->description); /* At this point, we don't need any more the device list. Free it */ pcap_freealldevs(alldevs); /* start the capture */ pcap_loop(adhandle, 0, packet_handler, NULL); return 0; } /* Callback function invoked by libpcap for every incoming packet */ void packet_handler(u_char *param, const struct pcap_pkthdr *header, const u_char *pkt_data) { struct tm ltime; char timestr[16]; ip_header *ih; udp_header *uh; u_int ip_len; u_short sport,dport; time_t local_tv_sec; /* * Unused variable */ (VOID)(param); /* convert the timestamp to readable format */ local_tv_sec = header->ts.tv_sec; localtime_s(<ime, &local_tv_sec); strftime( timestr, sizeof timestr, "%H:%M:%S", <ime); /* print timestamp and length of the packet */ printf("%s.%.6d len:%d ", timestr, header->ts.tv_usec, header->len); /* retireve the position of the ip header */ ih = (ip_header *) (pkt_data + 14); //length of ethernet header /* retireve the position of the udp header */ ip_len = (ih->ver_ihl & 0xf) * 4; uh = (udp_header *) ((u_char*)ih + ip_len); /* convert from network byte order to host byte order */ sport = ntohs( uh->sport ); dport = ntohs( uh->dport ); /* print ip addresses and udp ports */ printf("%d.%d.%d.%d.%d -> %d.%d.%d.%d.%d\n", ih->saddr.byte1, ih->saddr.byte2, ih->saddr.byte3, ih->saddr.byte4, sport, ih->daddr.byte1, ih->daddr.byte2, ih->daddr.byte3, ih->daddr.byte4, dport); }
6.发送数据包
（1）
#include <stdlib.h> #include <stdio.h> #include <pcap.h> void main(int argc, char **argv) { pcap_t *fp; char errbuf[PCAP_ERRBUF_SIZE]; u_char packet[100]; int i; /* Check the validity of the command line */ if (argc != 2) { printf("usage: %s interface (e.g. 'rpcap://eth0')", argv[0]); return; } /* Open the output device */ if ( (fp= pcap_open(argv[1], // name of the device 100, // portion of the packet to capture (only the first 100 bytes) PCAP_OPENFLAG_PROMISCUOUS, // promiscuous mode 1000, // read timeout NULL, // authentication on the remote machine errbuf // error buffer ) ) == NULL) { fprintf(stderr,"\nUnable to open the adapter. %s is not supported by WinPcap\n", argv[1]); return; } /* Supposing to be on ethernet, set mac destination to 1:1:1:1:1:1 */ packet[0]=1; packet[1]=1; packet[2]=1; packet[3]=1; packet[4]=1; packet[5]=1; /* set mac source to 2:2:2:2:2:2 */ packet[6]=2; packet[7]=2; packet[8]=2; packet[9]=2; packet[10]=2; packet[11]=2; /* Fill the rest of the packet */ for(i=12;i<100;i++) { packet[i]=(u_char)i; } /* Send down the packet */ if (pcap_sendpacket(fp, packet, 100 /* size */) != 0) { fprintf(stderr,"\nError sending the packet: %s\n", pcap_geterr(fp)); return; } return; }
（2）
#include <stdlib.h> #include <stdio.h> #include <pcap.h> void usage(); void main(int argc, char **argv) { pcap_t *indesc,*outdesc; char errbuf[PCAP_ERRBUF_SIZE]; char source[PCAP_BUF_SIZE]; FILE *capfile; int caplen, sync; u_int res; pcap_send_queue *squeue; struct pcap_pkthdr *pktheader; u_char *pktdata; float cpu_time; u_int npacks = 0; errno_t fopen_error; /* Check the validity of the command line */ if (argc <= 2 || argc >= 5) { usage(); return; } /* Retrieve the length of the capture file */ fopen_error = fopen_s(&capfile, argv[1],"rb"); if(fopen_error != 0){ printf("Error opening the file, errno %d.\n", fopen_error); return; } fseek(capfile , 0, SEEK_END); caplen= ftell(capfile)- sizeof(struct pcap_file_header); fclose(capfile); /* Chek if the timestamps must be respected */ if(argc == 4 && argv[3][0] == 's') sync = TRUE; else sync = FALSE; /* Open the capture */ /* Create the source string according to the new WinPcap syntax */ if ( pcap_createsrcstr( source, // variable that will keep the source string PCAP_SRC_FILE, // we want to open a file NULL, // remote host NULL, // port on the remote host argv[1], // name of the file we want to open errbuf // error buffer ) != 0) { fprintf(stderr,"\nError creating a source string\n"); return; } /* Open the capture file */ if ( (indesc= pcap_open(source, 65536, PCAP_OPENFLAG_PROMISCUOUS, 1000, NULL, errbuf) ) == NULL) { fprintf(stderr,"\nUnable to open the file %s.\n", source); return; } /* Open the output adapter */ if ( (outdesc= pcap_open(argv[2], 100, PCAP_OPENFLAG_PROMISCUOUS, 1000, NULL, errbuf) ) == NULL) { fprintf(stderr,"\nUnable to open adapter %s.\n", source); return; } /* Check the MAC type */ if (pcap_datalink(indesc) != pcap_datalink(outdesc)) { printf("Warning: the datalink of the capture differs from the one of the selected interface.\n"); printf("Press a key to continue, or CTRL+C to stop.\n"); getchar(); } /* Allocate a send queue */ squeue = pcap_sendqueue_alloc(caplen); /* Fill the queue with the packets from the file */ while ((res = pcap_next_ex( indesc, &pktheader, &pktdata)) == 1) { if (pcap_sendqueue_queue(squeue, pktheader, pktdata) == -1) { printf("Warning: packet buffer too small, not all the packets will be sent.\n"); break; } npacks++; } if (res == -1) { printf("Corrupted input file.\n"); pcap_sendqueue_destroy(squeue); return; } /* Transmit the queue */ cpu_time = (float)clock (); if ((res = pcap_sendqueue_transmit(outdesc, squeue, sync)) < squeue->len) { printf("An error occurred sending the packets: %s. Only %d bytes were sent\n", pcap_geterr(outdesc), res); } cpu_time = (clock() - cpu_time)/CLK_TCK; printf ("\n\nElapsed time: %5.3f\n", cpu_time); printf ("\nTotal packets generated = %d", npacks); printf ("\nAverage packets per second = %d", (int)((double)npacks/cpu_time)); printf ("\n"); /* free the send queue */ pcap_sendqueue_destroy(squeue); /* Close the input file */ pcap_close(indesc); /* * lose the output adapter * IMPORTANT: remember to close the adapter, otherwise there will be no guarantee that all the * packets will be sent! */ pcap_close(outdesc); return; } void usage() { printf("\nSendcap, sends a libpcap/tcpdump capture file to the net. Copyright (C) 2002 Loris Degioanni.\n"); printf("\nUsage:\n"); printf("\t sendcap file_name adapter [s]\n"); printf("\nParameters:\n"); printf("\nfile_name: the name of the dump file that will be sent to the network\n"); printf("\nadapter: the device to use. Use \"WinDump -D\" for a list of valid devices\n"); printf("\ns: if present, forces the packets to be sent synchronously, i.e. respecting the timestamps in the dump file. This option will work only under Windows NTx.\n\n"); exit(0); }
#include "pcap.h" main() { pcap_if_t *alldevs; pcap_if_t *d; int i=0; char errbuf[PCAP_ERRBUF_SIZE]; /* Retrieve the device list from the local machine */ if (pcap_findalldevs_ex(PCAP_SRC_IF_STRING, NULL /* auth is not needed */, &alldevs, errbuf) == -1) { fprintf(stderr,"Error in pcap_findalldevs_ex: %s\n", errbuf); exit(1); } /* Print the list */ for(d= alldevs; d != NULL; d= d->next) { printf("%d. %s", ++i, d->name); if (d->description) printf(" (%s)\n", d->description); else printf(" (No description available)\n"); } if (i == 0) { printf("\nNo interfaces found! Make sure WinPcap is installed.\n"); return; } /* We don't need any more the device list. Free it */ pcap_freealldevs(alldevs); }