| 1 | /* ARP */ |
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| 2 | #include <netinet/ether.h> |
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| 3 | #include <netinet/in.h> |
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| 4 | #include <stdio.h> |
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| 5 | #include <inttypes.h> |
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| 6 | #include <dlfcn.h> |
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| 7 | #include <map> |
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| 8 | #include "libpacketdump.h" |
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| 9 | #include <sys/socket.h> |
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| 10 | #include <netinet/in.h> |
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| 11 | #include <netinet/ip.h> |
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| 12 | #include <net/if_arp.h> |
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| 13 | #include <arpa/inet.h> |
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| 14 | |
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| 15 | #define DISPLAY_EXP(x,fmt,exp) \ |
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| 16 | if ((unsigned int)len>=((char*)&ip->x-(char*)ip+sizeof(ip->x))) \ |
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| 17 | printf(fmt,exp); \ |
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| 18 | else \ |
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| 19 | return; |
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| 20 | |
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| 21 | #define DISPLAY(x,fmt) DISPLAY_EXP(x,fmt,ip->x) |
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| 22 | |
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| 23 | #define DISPLAYS(x,fmt) DISPLAY_EXP(x,fmt,htons(ip->x)) |
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| 24 | #define DISPLAYIP(x,fmt) DISPLAY_EXP(x,fmt,inet_ntoa(*(struct in_addr*)&ip->x)) |
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| 25 | |
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| 26 | static char *format(struct arphdr *arp, char *hrd, char *pro) |
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| 27 | { |
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| 28 | static char buffer[1024]; |
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| 29 | if (hrd==NULL) |
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| 30 | return "Truncated (Truncated)"; |
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| 31 | switch(arp->ar_hrd) { |
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| 32 | case ARPHRD_ETHER: |
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| 33 | strcpy(buffer,ether_ntoa((struct ether_addr*)&hrd)); |
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| 34 | break; |
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| 35 | default: |
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| 36 | int i; |
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| 37 | for (i=0;i<arp->ar_hln;i++) { |
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| 38 | snprintf(buffer,sizeof(buffer),"%s %02x", |
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| 39 | buffer,(unsigned char)hrd[i]); |
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| 40 | } |
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| 41 | } |
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| 42 | if (pro==NULL) { |
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| 43 | strncat(buffer," (Truncated)",sizeof(buffer)); |
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| 44 | return buffer; |
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| 45 | } |
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| 46 | switch(arp->ar_pro) { |
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| 47 | case 0x0800: |
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| 48 | snprintf(buffer,sizeof(buffer),"%s (%s)", |
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| 49 | buffer,inet_ntoa(*(struct in_addr*)&pro)); |
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| 50 | break; |
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| 51 | default: |
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| 52 | int i; |
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| 53 | strncat(buffer," (",sizeof(buffer)); |
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| 54 | for (i=0;i<arp->ar_pln;i++) { |
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| 55 | snprintf(buffer,sizeof(buffer),"%s %02x", |
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| 56 | buffer,(unsigned char)pro[i]); |
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| 57 | } |
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| 58 | strncat(buffer,")",sizeof(buffer)); |
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| 59 | break; |
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| 60 | } |
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| 61 | return buffer; |
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| 62 | } |
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| 63 | |
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| 64 | extern "C" |
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| 65 | void decode(int link_type,char *packet,int len) |
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| 66 | { |
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| 67 | struct arphdr *arp = (struct arphdr*)packet; |
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| 68 | char *source_hrd = NULL; |
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| 69 | char *source_pro = NULL; |
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| 70 | char *dest_hrd = NULL; |
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| 71 | char *dest_pro = NULL; |
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| 72 | if (len<8) |
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| 73 | return; |
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| 74 | if (sizeof(*arp)<=(unsigned int)len) |
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| 75 | source_hrd=packet+sizeof(arp); |
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| 76 | if (source_hrd && source_hrd-packet+arp->ar_hln<=len) |
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| 77 | source_pro =source_hrd+arp->ar_hln; |
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| 78 | if (source_pro && source_pro-packet+arp->ar_pln<=len) |
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| 79 | dest_hrd =source_pro +arp->ar_pln; |
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| 80 | if (dest_hrd && dest_hrd-packet+arp->ar_pln<=len) |
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| 81 | dest_pro =dest_hrd +arp->ar_hln; |
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| 82 | switch(arp->ar_op) { |
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| 83 | case ARPOP_REQUEST: |
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| 84 | printf(" ARP: Who-has %s", |
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| 85 | format(arp,source_hrd,source_pro)); |
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| 86 | printf(" please tell %s", |
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| 87 | format(arp,dest_hrd,dest_pro)); |
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| 88 | break; |
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| 89 | default: |
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| 90 | printf(" ARP: Unknown opcode (%i) from %s", |
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| 91 | arp->ar_op, |
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| 92 | format(arp,source_hrd,source_pro)); |
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| 93 | printf(" to %s", |
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| 94 | format(arp,dest_hrd,dest_pro)); |
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| 95 | break; |
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| 96 | } |
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| 97 | return; |
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| 98 | } |
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