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