tc/f_fw.c

   1 /*
   2  * f_fw.c               FW filter.
   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:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  10  *
  11  */
  12
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <unistd.h>
  16 #include <fcntl.h>
  17 #include <sys/socket.h>
  18 #include <netinet/in.h>
  19 #include <arpa/inet.h>
  20 #include <string.h>
  21 #include <linux/if.h> /* IFNAMSIZ */
  22 #include "utils.h"
  23 #include "tc_util.h"
  24
  25 static void explain(void)
  26 {
  27         fprintf(stderr,
  28                 "Usage: ... fw [ classid CLASSID ] [ indev DEV ] [ action ACTION_SPEC ]\n");
  29         fprintf(stderr,
  30                 "       CLASSID := Push matching packets to the class identified by CLASSID with format X:Y\n");
  31         fprintf(stderr,
  32                 "                  CLASSID is parsed as hexadecimal input.\n");
  33         fprintf(stderr,
  34                 "       DEV := specify device for incoming device classification.\n");
  35         fprintf(stderr,
  36                 "       ACTION_SPEC := Apply an action on matching packets.\n");
  37         fprintf(stderr,
  38                 "       NOTE: handle is represented as HANDLE[/FWMASK].\n");
  39         fprintf(stderr, "             FWMASK is 0xffffffff by default.\n");
  40 }
  41
  42 static int fw_parse_opt(struct filter_util *qu, char *handle, int argc, char **argv, struct nlmsghdr *n)
  43 {
  44         struct tcmsg *t = NLMSG_DATA(n);
  45         struct rtattr *tail;
  46         __u32 mask = 0;
  47         int mask_set = 0;
  48
  49         if (handle) {
  50                 char *slash;
  51
  52                 if ((slash = strchr(handle, '/')) != NULL)
  53                         *slash = '\0';
  54                 if (get_u32(&t->tcm_handle, handle, 0)) {
  55                         fprintf(stderr, "Illegal \"handle\"\n");
  56                         return -1;
  57                 }
  58                 if (slash) {
  59                         if (get_u32(&mask, slash+1, 0)) {
  60                                 fprintf(stderr, "Illegal \"handle\" mask\n");
  61                                 return -1;
  62                         }
  63                         mask_set = 1;
  64                 }
  65         }
  66
  67         if (argc == 0)
  68                 return 0;
  69
  70         tail = NLMSG_TAIL(n);
  71         addattr_l(n, 4096, TCA_OPTIONS, NULL, 0);
  72
  73         if (mask_set)
  74                 addattr32(n, MAX_MSG, TCA_FW_MASK, mask);
  75
  76         while (argc > 0) {
  77                 if (matches(*argv, "classid") == 0 ||
  78                     matches(*argv, "flowid") == 0) {
  79                         unsigned int handle;
  80
  81                         NEXT_ARG();
  82                         if (get_tc_classid(&handle, *argv)) {
  83                                 fprintf(stderr, "Illegal \"classid\"\n");
  84                                 return -1;
  85                         }
  86                         addattr_l(n, 4096, TCA_FW_CLASSID, &handle, 4);
  87                 } else if (matches(*argv, "police") == 0) {
  88                         NEXT_ARG();
  89                         if (parse_police(&argc, &argv, TCA_FW_POLICE, n)) {
  90                                 fprintf(stderr, "Illegal \"police\"\n");
  91                                 return -1;
  92                         }
  93                         continue;
  94                 } else if (matches(*argv, "action") == 0) {
  95                         NEXT_ARG();
  96                         if (parse_action(&argc, &argv, TCA_FW_ACT, n)) {
  97                                 fprintf(stderr, "Illegal fw \"action\"\n");
  98                                 return -1;
  99                         }
 100                         continue;
 101                 } else if (strcmp(*argv, "indev") == 0) {
 102                         char d[IFNAMSIZ+1] = {};
 103
 104                         argc--;
 105                         argv++;
 106                         if (argc < 1) {
 107                                 fprintf(stderr, "Illegal indev\n");
 108                                 return -1;
 109                         }
 110                         strncpy(d, *argv, sizeof(d) - 1);
 111                         addattr_l(n, MAX_MSG, TCA_FW_INDEV, d, strlen(d) + 1);
 112                 } else if (strcmp(*argv, "help") == 0) {
 113                         explain();
 114                         return -1;
 115                 } else {
 116                         fprintf(stderr, "What is \"%s\"?\n", *argv);
 117                         explain();
 118                         return -1;
 119                 }
 120                 argc--; argv++;
 121         }
 122         tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 123         return 0;
 124 }
 125
 126 static int fw_print_opt(struct filter_util *qu, FILE *f, struct rtattr *opt, __u32 handle)
 127 {
 128         struct rtattr *tb[TCA_FW_MAX+1];
 129
 130         if (opt == NULL)
 131                 return 0;
 132
 133         parse_rtattr_nested(tb, TCA_FW_MAX, opt);
 134
 135         if (handle || tb[TCA_FW_MASK]) {
 136                 __u32 mark = 0, mask = 0;
 137
 138                 if (handle)
 139                         mark = handle;
 140                 if (tb[TCA_FW_MASK] &&
 141                     (mask = rta_getattr_u32(tb[TCA_FW_MASK])) != 0xFFFFFFFF)
 142                         fprintf(f, "handle 0x%x/0x%x ", mark, mask);
 143                 else
 144                         fprintf(f, "handle 0x%x ", handle);
 145         }
 146
 147         if (tb[TCA_FW_CLASSID]) {
 148                 SPRINT_BUF(b1);
 149                 fprintf(f, "classid %s ", sprint_tc_classid(rta_getattr_u32(tb[TCA_FW_CLASSID]), b1));
 150         }
 151
 152         if (tb[TCA_FW_POLICE])
 153                 tc_print_police(f, tb[TCA_FW_POLICE]);
 154         if (tb[TCA_FW_INDEV]) {
 155                 struct rtattr *idev = tb[TCA_FW_INDEV];
 156
 157                 fprintf(f, "input dev %s ", rta_getattr_str(idev));
 158         }
 159
 160         if (tb[TCA_FW_ACT]) {
 161                 fprintf(f, "\n");
 162                 tc_print_action(f, tb[TCA_FW_ACT], 0);
 163         }
 164         return 0;
 165 }
 166
 167 struct filter_util fw_filter_util = {
 168         .id = "fw",
 169         .parse_fopt = fw_parse_opt,
 170         .print_fopt = fw_print_opt,
 171 };