dissector.h

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * Copyright 2009 - 2013 Daniel Borkmann.
   4  * Subject to the GPL, version 2.
   5  */
   6
   7 #ifndef DISSECTOR_H
   8 #define DISSECTOR_H
   9
  10 #include <stdlib.h>
  11 #include <stdint.h>
  12 #include <sys/socket.h>
  13 #include <linux/if_packet.h>
  14 #include <linux/if.h>
  15 #include <netlink/msg.h>
  16
  17 #include "ring.h"
  18 #include "tprintf.h"
  19 #include "linktype.h"
  20 #include "proto_vlan.h"
  21
  22 #define PRINT_NORM              0
  23 #define PRINT_LESS              1
  24 #define PRINT_HEX               2
  25 #define PRINT_ASCII             3
  26 #define PRINT_HEX_ASCII         4
  27 #define PRINT_NONE              5
  28
  29 extern char *if_indextoname(unsigned ifindex, char *ifname);
  30
  31 static const char * const packet_types[256] = {
  32         [PACKET_HOST]           =       "<",  /* Incoming */
  33         [PACKET_BROADCAST]      =       "B",  /* Broadcast */
  34         [PACKET_MULTICAST]      =       "M",  /* Multicast */
  35         [PACKET_OTHERHOST]      =       "P",  /* Promisc */
  36         [PACKET_OUTGOING]       =       ">",  /* Outgoing */
  37         [PACKET_USER]           =       "K->U", /* To Userspace */
  38         [PACKET_KERNEL]         =       "U->K", /* To Kernelspace */
  39 };
  40
  41 static inline const char *__show_ts_source(uint32_t status)
  42 {
  43         if (status & TP_STATUS_TS_RAW_HARDWARE)
  44                 return "(raw hw ts)";
  45         else if (status & TP_STATUS_TS_SYS_HARDWARE)
  46                 return "(sys hw ts)";
  47         else if (status & TP_STATUS_TS_SOFTWARE)
  48                 return "(sw ts)";
  49         else
  50                 return "";
  51 }
  52
  53 static inline void __show_frame_hdr(uint8_t *packet, size_t len, int linktype,
  54                                     struct sockaddr_ll *s_ll, void *raw_hdr,
  55                                     int mode, bool v3, unsigned long count)
  56 {
  57         char tmp[IFNAMSIZ];
  58         union tpacket_uhdr hdr;
  59         uint8_t pkttype = s_ll->sll_pkttype;
  60         bool is_nl;
  61
  62         if (mode == PRINT_NONE)
  63                 return;
  64
  65         /*
  66          * If we're capturing on nlmon0, all packets will have sll_pkttype set
  67          * to PACKET_OUTGOING, but we actually want PACKET_USER/PACKET_KERNEL as
  68          * it originally was set in the kernel. Thus, use nlmsghdr->nlmsg_pid to
  69          * restore the type.
  70          */
  71         is_nl = (linktype == LINKTYPE_NETLINK && len >= sizeof(struct nlmsghdr));
  72         if (is_nl && pkttype == PACKET_OUTGOING) {
  73                 struct nlmsghdr *hdr = (struct nlmsghdr *) packet;
  74                 pkttype = hdr->nlmsg_pid == 0 ? PACKET_KERNEL : PACKET_USER;
  75         }
  76
  77         hdr.raw = raw_hdr;
  78         switch (mode) {
  79         case PRINT_LESS:
  80                 tprintf("%s %s %u #%lu",
  81                         packet_types[pkttype] ? : "?",
  82                         if_indextoname(s_ll->sll_ifindex, tmp) ? : "?",
  83                         tpacket_uhdr(hdr, tp_len, v3),
  84                         count);
  85                 break;
  86         default:
  87                 tprintf("%s %s %u %us.%uns #%lu %s\n",
  88                         packet_types[pkttype] ? : "?",
  89                         if_indextoname(s_ll->sll_ifindex, tmp) ? : "?",
  90                         tpacket_uhdr(hdr, tp_len, v3),
  91                         tpacket_uhdr(hdr, tp_sec, v3),
  92                         tpacket_uhdr(hdr, tp_nsec, v3),
  93                         count,
  94                         v3 ? "" : __show_ts_source(hdr.h2->tp_status));
  95
  96                 if (tpacket_has_vlan_info(&hdr)) {
  97                         uint16_t tci = tpacket_uhdr_vlan_tci(&hdr, v3);
  98
  99                         tprintf(" [ tpacketv3 VLAN ");
 100                         tprintf("Prio (%u), ", vlan_tci2prio(tci));
 101                         tprintf("CFI (%u), ", vlan_tci2cfi(tci));
 102                         tprintf("ID (%u), ", vlan_tci2vid(tci));
 103                         tprintf("Proto (0x%.4x)", tpacket_uhdr_vlan_proto(&hdr, v3));
 104                         tprintf(" ]\n");
 105                 }
 106                 break;
 107         }
 108 }
 109
 110 static inline void show_frame_hdr(uint8_t *packet, size_t len, int linktype,
 111                                   struct frame_map *hdr, int mode,
 112                                   unsigned long count)
 113 {
 114         __show_frame_hdr(packet, len, linktype, &hdr->s_ll, &hdr->tp_h, mode,
 115                          false, count);
 116 }
 117
 118 extern void dissector_init_all(int fnttype);
 119 extern void dissector_entry_point(uint8_t *packet, size_t len, int linktype,
 120                                   int mode, struct sockaddr_ll *sll);
 121 extern void dissector_cleanup_all(void);
 122 extern int dissector_set_print_type(void *ptr, int type);
 123
 124 #endif /* DISSECTOR_H */