genl/genl.c

   1 /*
   2  * genl.c               "genl" utility frontend.
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Authors:     Jamal Hadi Salim
  10  *
  11  */
  12
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <unistd.h>
  16 #include <fcntl.h>
  17 #include <dlfcn.h>
  18 #include <sys/socket.h>
  19 #include <netinet/in.h>
  20 #include <arpa/inet.h>
  21 #include <string.h>
  22 #include <errno.h>
  23 #include <linux/netlink.h>
  24 #include <linux/rtnetlink.h> /* until we put our own header */
  25 #include "SNAPSHOT.h"
  26 #include "utils.h"
  27 #include "genl_utils.h"
  28
  29 int show_stats;
  30 int show_details;
  31 int show_raw;
  32
  33 static void *BODY;
  34 static struct genl_util *genl_list;
  35
  36
  37 static int print_nofopt(struct nlmsghdr *n, void *arg)
  38 {
  39         fprintf((FILE *) arg, "unknown genl type ..\n");
  40         return 0;
  41 }
  42
  43 static int parse_nofopt(struct genl_util *f, int argc, char **argv)
  44 {
  45         if (argc) {
  46                 fprintf(stderr,
  47                         "Unknown genl \"%s\", hence option \"%s\" is unparsable\n",
  48                         f->name, *argv);
  49                 return -1;
  50         }
  51
  52         return 0;
  53 }
  54
  55 static struct genl_util *get_genl_kind(const char *str)
  56 {
  57         void *dlh;
  58         char buf[256];
  59         struct genl_util *f;
  60
  61         for (f = genl_list; f; f = f->next)
  62                 if (strcmp(f->name, str) == 0)
  63                         return f;
  64
  65         snprintf(buf, sizeof(buf), "%s.so", str);
  66         dlh = dlopen(buf, RTLD_LAZY);
  67         if (dlh == NULL) {
  68                 dlh = BODY;
  69                 if (dlh == NULL) {
  70                         dlh = BODY = dlopen(NULL, RTLD_LAZY);
  71                         if (dlh == NULL)
  72                                 goto noexist;
  73                 }
  74         }
  75
  76         snprintf(buf, sizeof(buf), "%s_genl_util", str);
  77
  78         f = dlsym(dlh, buf);
  79         if (f == NULL)
  80                 goto noexist;
  81 reg:
  82         f->next = genl_list;
  83         genl_list = f;
  84         return f;
  85
  86 noexist:
  87         f = calloc(1, sizeof(*f));
  88         if (f) {
  89                 strncpy(f->name, str, 15);
  90                 f->parse_genlopt = parse_nofopt;
  91                 f->print_genlopt = print_nofopt;
  92                 goto reg;
  93         }
  94         return f;
  95 }
  96
  97 static void usage(void) __attribute__((noreturn));
  98
  99 static void usage(void)
 100 {
 101         fprintf(stderr,
 102                 "Usage: genl [ OPTIONS ] OBJECT [help] }\n"
 103                 "where  OBJECT := { ctrl etc }\n"
 104                 "       OPTIONS := { -s[tatistics] | -d[etails] | -r[aw] | -V[ersion] | -h[elp] }\n");
 105         exit(-1);
 106 }
 107
 108 int main(int argc, char **argv)
 109 {
 110         while (argc > 1) {
 111                 if (argv[1][0] != '-')
 112                         break;
 113                 if (matches(argv[1], "-stats") == 0 ||
 114                     matches(argv[1], "-statistics") == 0) {
 115                         ++show_stats;
 116                 } else if (matches(argv[1], "-details") == 0) {
 117                         ++show_details;
 118                 } else if (matches(argv[1], "-raw") == 0) {
 119                         ++show_raw;
 120                 } else if (matches(argv[1], "-Version") == 0) {
 121                         printf("genl utility, iproute2-ss%s\n", SNAPSHOT);
 122                         exit(0);
 123                 } else if (matches(argv[1], "-help") == 0) {
 124                         usage();
 125                 } else {
 126                         fprintf(stderr,
 127                                 "Option \"%s\" is unknown, try \"genl -help\".\n",
 128                                 argv[1]);
 129                         exit(-1);
 130                 }
 131                 argc--; argv++;
 132         }
 133
 134         if (argc > 1) {
 135                 struct genl_util *a;
 136                 int ret;
 137
 138                 a = get_genl_kind(argv[1]);
 139                 if (!a) {
 140                         fprintf(stderr, "bad genl %s\n", argv[1]);
 141                         exit(-1);
 142                 }
 143
 144                 ret = a->parse_genlopt(a, argc-1, argv+1);
 145                 return ret;
 146         }
 147
 148         usage();
 149 }