src/nl-pktloc-lookup.c

   1 /*
   2  * src/nl-pktloc-lookup.c     Lookup packet location alias
   3  *
   4  *      This library is free software; you can redistribute it and/or
   5  *      modify it under the terms of the GNU Lesser General Public
   6  *      License as published by the Free Software Foundation version 2.1
   7  *      of the License.
   8  *
   9  * Copyright (c) 2010 Thomas Graf <tgraf@suug.ch>
  10  */
  11
  12 #include <netlink/cli/utils.h>
  13 #include <netlink/route/pktloc.h>
  14
  15 static void print_usage(void)
  16 {
  17 printf(
  18 "Usage: nl-pktloc-lookup [OPTIONS] <name>\n"
  19 "\n"
  20 "OPTIONS\n"
  21 " -h, --help                Show this help text.\n"
  22 " -v, --version             Show versioning information.\n"
  23 " -l, --list                List all packet location definitions.\n"
  24 "     --u32=VALUE           Print in iproute2's u32 selector style\n"
  25 "\n"
  26 "\n"
  27 "EXAMPLE\n"
  28 "   $ nl-pktloc-lookup ip.dst\n"
  29 "   $ nl-pktloc-lookup --list\n"
  30 "\n"
  31 );
  32         exit(0);
  33 }
  34
  35 static const char *align_txt[] = {
  36         [TCF_EM_ALIGN_U8] = "u8",
  37         [TCF_EM_ALIGN_U16] = "u16",
  38         [TCF_EM_ALIGN_U32] = "u32"
  39 };
  40
  41 static uint32_t align_mask[] = {
  42         [TCF_EM_ALIGN_U8] = 0xff,
  43         [TCF_EM_ALIGN_U16] = 0xffff,
  44         [TCF_EM_ALIGN_U32] = 0xffffffff,
  45 };
  46
  47 static const char *layer_txt[] = {
  48         [TCF_LAYER_LINK] = "eth",
  49         [TCF_LAYER_NETWORK] = "ip",
  50         [TCF_LAYER_TRANSPORT] = "tcp"
  51 };
  52
  53 static void dump_u32_style(struct rtnl_pktloc *loc, uint32_t value)
  54 {
  55         if (loc->align > 4)
  56                 nl_cli_fatal(EINVAL, "u32 only supports alignments u8|u16|u32.");
  57
  58         if (loc->layer == TCF_LAYER_LINK)
  59                 nl_cli_fatal(EINVAL, "u32 does not support link "
  60                                 "layer locations.");
  61
  62         if (loc->shift > 0)
  63                 nl_cli_fatal(EINVAL, "u32 does not support shifting.");
  64
  65         printf("%s %x %x at %s%u\n",
  66                 align_txt[loc->align],
  67                 value, loc->mask ? loc->mask : align_mask[loc->align],
  68                 loc->layer == TCF_LAYER_TRANSPORT ? "nexthdr+" : "",
  69                 loc->offset);
  70 }
  71
  72 static char *get_align_txt(struct rtnl_pktloc *loc)
  73 {
  74         static char buf[16];
  75
  76         if (loc->align <= 4)
  77                 strcpy(buf, align_txt[loc->align]);
  78         else
  79                 snprintf(buf, sizeof(buf), "%u", loc->align);
  80
  81         return buf;
  82 }
  83
  84 static void dump_loc(struct rtnl_pktloc *loc)
  85 {
  86         printf("%s = %s at %s+%u & %#x >> %u\n",
  87                 loc->name, get_align_txt(loc), layer_txt[loc->layer],
  88                 loc->offset, loc->mask, loc->shift);
  89 }
  90
  91 static void list_cb(struct rtnl_pktloc *loc, void *arg)
  92 {
  93         printf("%-26s %-5s %3s+%-4u %#-10x %-8u %u\n",
  94                 loc->name, get_align_txt(loc), layer_txt[loc->layer],
  95                 loc->offset, loc->mask, loc->shift, loc->refcnt);
  96 }
  97
  98 static void do_list(void)
  99 {
 100         printf(
 101 "name                      align  offset  mask     shift    refcnt\n");
 102         printf("---------------------------------------------------------\n");
 103
 104         rtnl_pktloc_foreach(&list_cb, NULL);
 105 }
 106
 107 int main(int argc, char *argv[])
 108 {
 109         struct rtnl_pktloc *loc;
 110         int err, ustyle = 0;
 111         uint32_t uvalue = 0;
 112
 113         for (;;) {
 114                 int c, optidx = 0;
 115                 enum {
 116                         ARG_U32 = 257,
 117                 };
 118                 static struct option long_opts[] = {
 119                         { "help", 0, 0, 'h' },
 120                         { "version", 0, 0, 'v' },
 121                         { "list", 0, 0, 'l' },
 122                         { "u32", 1, 0, ARG_U32 },
 123                         { 0, 0, 0, 0 }
 124                 };
 125
 126                 c = getopt_long(argc, argv, "hvl", long_opts, &optidx);
 127                 if (c == -1)
 128                         break;
 129
 130                 switch (c) {
 131                 case 'h': print_usage(); break;
 132                 case 'v': nl_cli_print_version(); break;
 133                 case 'l': do_list(); exit(0);
 134                 case ARG_U32:
 135                         ustyle = 1;
 136                         uvalue = nl_cli_parse_u32(optarg);
 137                         break;
 138                 }
 139         }
 140
 141         if (optind >= argc)
 142                 print_usage();
 143
 144         if ((err = rtnl_pktloc_lookup(argv[optind++], &loc)) < 0)
 145                 nl_cli_fatal(err, "Unable to lookup packet location: %s",
 146                         nl_geterror(err));
 147
 148         if (ustyle)
 149                 dump_u32_style(loc, uvalue);
 150         else
 151                 dump_loc(loc);
 152
 153         return 0;
 154 }