proto_nlmsg.c

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * Copyright 2014 Tobias Klauser.
   4  * Subject to the GPL, version 2.
   5  */
   6
   7 #include <stdio.h>
   8 #include <unistd.h>
   9 #include <libnl3/netlink/msg.h>
  10 #include <libgen.h>
  11
  12 #include "pkt_buff.h"
  13 #include "proto.h"
  14
  15 static void nlmsg(struct pkt_buff *pkt)
  16 {
  17         struct nlmsghdr *hdr = (struct nlmsghdr *) pkt_pull(pkt, sizeof(*hdr));
  18         char type[32];
  19         char flags[128];
  20         char procname[1024];
  21
  22         if (hdr == NULL)
  23                 return;
  24
  25         /* Look up the process name if message is not coming from the kernel */
  26         if (hdr->nlmsg_pid != 0) {
  27                 char path[1024];
  28                 int ret;
  29
  30                 snprintf(path, sizeof(path), "/proc/%u/exe", hdr->nlmsg_pid);
  31                 ret = readlink(path, procname, sizeof(procname) - 1);
  32                 if (ret < 0)
  33                         procname[0] = '\0';
  34         } else
  35                 snprintf(procname, sizeof(procname), "kernel");
  36
  37         tprintf(" [ NLMSG ");
  38         tprintf("Len %u, ", hdr->nlmsg_len);
  39         tprintf("Type 0x%.4x (%s%s%s), ", hdr->nlmsg_type,
  40                 colorize_start(bold),
  41                 nl_nlmsgtype2str(hdr->nlmsg_type, type, sizeof(type)),
  42                 colorize_end());
  43         tprintf("Flags 0x%.4x (%s%s%s), ", hdr->nlmsg_flags,
  44                 colorize_start(bold),
  45                 nl_nlmsg_flags2str(hdr->nlmsg_flags, flags, sizeof(flags)),
  46                 colorize_end());
  47         tprintf("Seq-Nr %u, ", hdr->nlmsg_seq);
  48         tprintf("PID %u", hdr->nlmsg_pid);
  49         if (procname[0])
  50                 tprintf(" (%s%s%s)", colorize_start(bold), basename(procname),
  51                         colorize_end());
  52         tprintf(" ]\n");
  53 }
  54
  55 static void nlmsg_less(struct pkt_buff *pkt)
  56 {
  57         struct nlmsghdr *hdr = (struct nlmsghdr *) pkt_pull(pkt, sizeof(*hdr));
  58         char type[32];
  59
  60         if (hdr == NULL)
  61                 return;
  62
  63         tprintf(" NLMSG %u (%s%s%s)", hdr->nlmsg_type, colorize_start(bold),
  64                 nl_nlmsgtype2str(hdr->nlmsg_type, type, sizeof(type)),
  65                 colorize_end());
  66 }
  67
  68 struct protocol nlmsg_ops = {
  69         .print_full = nlmsg,
  70         .print_less = nlmsg_less,
  71 };