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 <libnl3/netlink/msg.h>
  16
  17 #include "ring.h"
  18 #include "tprintf.h"
  19
  20 #define PRINT_NORM              0
  21 #define PRINT_LESS              1
  22 #define PRINT_HEX               2
  23 #define PRINT_ASCII             3
  24 #define PRINT_HEX_ASCII         4
  25 #define PRINT_NONE              5
  26
  27 extern char *if_indextoname(unsigned ifindex, char *ifname);
  28
  29 static const char * const packet_types[256] = {
  30         [0 ... 255]             =       "?",  /* Unknown */
  31         [PACKET_HOST]           =       "<",  /* Incoming */
  32         [PACKET_BROADCAST]      =       "B",  /* Broadcast */
  33         [PACKET_MULTICAST]      =       "M",  /* Multicast */
  34         [PACKET_OTHERHOST]      =       "P",  /* Promisc */
  35         [PACKET_OUTGOING]       =       ">",  /* Outgoing */
  36         [PACKET_USER]           =       ">U", /* To Userspace */
  37         [PACKET_KERNEL]         =       ">K", /* To Kernelspace */
  38 };
  39
  40 static inline const char *__show_ts_source(uint32_t status)
  41 {
  42         if (status & TP_STATUS_TS_RAW_HARDWARE)
  43                 return "(raw hw ts)";
  44         else if (status & TP_STATUS_TS_SYS_HARDWARE)
  45                 return "(sys hw ts)";
  46         else if (status & TP_STATUS_TS_SOFTWARE)
  47                 return "(sw ts)";
  48         else
  49                 return "";
  50 }
  51
  52 static inline void __show_frame_hdr(uint8_t *packet, size_t len, int linktype,
  53                                     struct sockaddr_ll *s_ll, void *raw_hdr,
  54                                     int mode, bool v3)
  55 {
  56         char tmp[IFNAMSIZ];
  57         union tpacket_uhdr hdr;
  58         uint8_t pkttype = s_ll->sll_pkttype;
  59
  60         if (mode == PRINT_NONE)
  61                 return;
  62
  63         /*
  64          * If we're capturing on nlmon0, all packets will have sll_pkttype set
  65          * to PACKET_OUTGOING, but we actually want PACKET_USER/PACKET_KERNEL as
  66          * it originally was set in the kernel. Thus, use nlmsghdr->nlmsg_pid to
  67          * restore the type.
  68          */
  69         if (linktype == AF_NETLINK && len >= sizeof(struct nlmsghdr)) {
  70                 struct nlmsghdr *hdr = (struct nlmsghdr *) packet;
  71                 pkttype = hdr->nlmsg_pid == 0 ? PACKET_KERNEL : PACKET_USER;
  72         }
  73
  74         hdr.raw = raw_hdr;
  75         switch (mode) {
  76         case PRINT_LESS:
  77                 tprintf("%s %s %u",
  78                         packet_types[pkttype] ? : "?",
  79                         if_indextoname(s_ll->sll_ifindex, tmp) ? : "?",
  80                         v3 ? hdr.h3->tp_len : hdr.h2->tp_len);
  81                 break;
  82         default:
  83                 tprintf("%s %s %u %us.%uns %s\n",
  84                         packet_types[pkttype] ? : "?",
  85                         if_indextoname(s_ll->sll_ifindex, tmp) ? : "?",
  86                         v3 ? hdr.h3->tp_len : hdr.h2->tp_len,
  87                         v3 ? hdr.h3->tp_sec : hdr.h2->tp_sec,
  88                         v3 ? hdr.h3->tp_nsec : hdr.h2->tp_nsec,
  89                         v3 ? "" : __show_ts_source(hdr.h2->tp_status));
  90                 break;
  91         }
  92 }
  93
  94 static inline void show_frame_hdr(uint8_t *packet, size_t len, int linktype,
  95                                   struct frame_map *hdr, int mode)
  96 {
  97         __show_frame_hdr(packet, len, linktype, &hdr->s_ll, &hdr->tp_h, mode, false);
  98 }
  99
 100 extern void dissector_init_all(int fnttype);
 101 extern void dissector_entry_point(uint8_t *packet, size_t len, int linktype, int mode);
 102 extern void dissector_cleanup_all(void);
 103 extern int dissector_set_print_type(void *ptr, int type);
 104
 105 #endif /* DISSECTOR_H */