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      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 (at) ms2.inr.ac.ru>
     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 <sys/socket.h>
     19 #include <netinet/in.h>
     20 #include <arpa/inet.h>
     21 #include <string.h>
     22 #include <linux/if.h> /* IFNAMSIZ */
     23 #include "utils.h"
     24 #include "tc_util.h"
     25 
     26 static void explain(void)
     27 {
     28 	fprintf(stderr,
     29 		"Usage: ... fw [ classid CLASSID ] [ indev DEV ] [ action ACTION_SPEC ]\n");
     30 	fprintf(stderr,
     31 		"       CLASSID := Push matching packets to the class identified by CLASSID with format X:Y\n");
     32 	fprintf(stderr,
     33 		"                  CLASSID is parsed as hexadecimal input.\n");
     34 	fprintf(stderr,
     35 		"       DEV := specify device for incoming device classification.\n");
     36 	fprintf(stderr,
     37 		"       ACTION_SPEC := Apply an action on matching packets.\n");
     38 	fprintf(stderr,
     39 		"       NOTE: handle is represented as HANDLE[/FWMASK].\n");
     40 	fprintf(stderr, "             FWMASK is 0xffffffff by default.\n");
     41 }
     42 
     43 static int fw_parse_opt(struct filter_util *qu, char *handle, int argc, char **argv, struct nlmsghdr *n)
     44 {
     45 	struct tcmsg *t = NLMSG_DATA(n);
     46 	struct rtattr *tail;
     47 	__u32 mask = 0;
     48 	int mask_set = 0;
     49 
     50 	if (handle) {
     51 		char *slash;
     52 
     53 		if ((slash = strchr(handle, '/')) != NULL)
     54 			*slash = '\0';
     55 		if (get_u32(&t->tcm_handle, handle, 0)) {
     56 			fprintf(stderr, "Illegal \"handle\"\n");
     57 			return -1;
     58 		}
     59 		if (slash) {
     60 			if (get_u32(&mask, slash+1, 0)) {
     61 				fprintf(stderr, "Illegal \"handle\" mask\n");
     62 				return -1;
     63 			}
     64 			mask_set = 1;
     65 		}
     66 	}
     67 
     68 	if (argc == 0)
     69 		return 0;
     70 
     71 	tail = NLMSG_TAIL(n);
     72 	addattr_l(n, 4096, TCA_OPTIONS, NULL, 0);
     73 
     74 	if (mask_set)
     75 		addattr32(n, MAX_MSG, TCA_FW_MASK, mask);
     76 
     77 	while (argc > 0) {
     78 		if (matches(*argv, "classid") == 0 ||
     79 		    matches(*argv, "flowid") == 0) {
     80 			unsigned int handle;
     81 
     82 			NEXT_ARG();
     83 			if (get_tc_classid(&handle, *argv)) {
     84 				fprintf(stderr, "Illegal \"classid\"\n");
     85 				return -1;
     86 			}
     87 			addattr_l(n, 4096, TCA_FW_CLASSID, &handle, 4);
     88 		} else if (matches(*argv, "police") == 0) {
     89 			NEXT_ARG();
     90 			if (parse_police(&argc, &argv, TCA_FW_POLICE, n)) {
     91 				fprintf(stderr, "Illegal \"police\"\n");
     92 				return -1;
     93 			}
     94 			continue;
     95 		} else if (matches(*argv, "action") == 0) {
     96 			NEXT_ARG();
     97 			if (parse_action(&argc, &argv, TCA_FW_ACT, n)) {
     98 				fprintf(stderr, "Illegal fw \"action\"\n");
     99 				return -1;
    100 			}
    101 			continue;
    102 		} else if (strcmp(*argv, "indev") == 0) {
    103 			char d[IFNAMSIZ+1] = {};
    104 
    105 			argc--;
    106 			argv++;
    107 			if (argc < 1) {
    108 				fprintf(stderr, "Illegal indev\n");
    109 				return -1;
    110 			}
    111 			strncpy(d, *argv, sizeof(d) - 1);
    112 			addattr_l(n, MAX_MSG, TCA_FW_INDEV, d, strlen(d) + 1);
    113 		} else if (strcmp(*argv, "help") == 0) {
    114 			explain();
    115 			return -1;
    116 		} else {
    117 			fprintf(stderr, "What is \"%s\"?\n", *argv);
    118 			explain();
    119 			return -1;
    120 		}
    121 		argc--; argv++;
    122 	}
    123 	tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
    124 	return 0;
    125 }
    126 
    127 static int fw_print_opt(struct filter_util *qu, FILE *f, struct rtattr *opt, __u32 handle)
    128 {
    129 	struct rtattr *tb[TCA_FW_MAX+1];
    130 
    131 	if (opt == NULL)
    132 		return 0;
    133 
    134 	parse_rtattr_nested(tb, TCA_FW_MAX, opt);
    135 
    136 	if (handle || tb[TCA_FW_MASK]) {
    137 		__u32 mark = 0, mask = 0;
    138 
    139 		if (handle)
    140 			mark = handle;
    141 		if (tb[TCA_FW_MASK] &&
    142 		    (mask = rta_getattr_u32(tb[TCA_FW_MASK])) != 0xFFFFFFFF)
    143 			fprintf(f, "handle 0x%x/0x%x ", mark, mask);
    144 		else
    145 			fprintf(f, "handle 0x%x ", handle);
    146 	}
    147 
    148 	if (tb[TCA_FW_CLASSID]) {
    149 		SPRINT_BUF(b1);
    150 		fprintf(f, "classid %s ", sprint_tc_classid(rta_getattr_u32(tb[TCA_FW_CLASSID]), b1));
    151 	}
    152 
    153 	if (tb[TCA_FW_POLICE])
    154 		tc_print_police(f, tb[TCA_FW_POLICE]);
    155 	if (tb[TCA_FW_INDEV]) {
    156 		struct rtattr *idev = tb[TCA_FW_INDEV];
    157 
    158 		fprintf(f, "input dev %s ", rta_getattr_str(idev));
    159 	}
    160 
    161 	if (tb[TCA_FW_ACT]) {
    162 		fprintf(f, "\n");
    163 		tc_print_action(f, tb[TCA_FW_ACT], 0);
    164 	}
    165 	return 0;
    166 }
    167 
    168 struct filter_util fw_filter_util = {
    169 	.id = "fw",
    170 	.parse_fopt = fw_parse_opt,
    171 	.print_fopt = fw_print_opt,
    172 };
    173