pktmnglr/packet_mangler.c

   1 /*
   2  * Copyright (c) 2014 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 //
  30 //  Created by Prabhakar Lakhera on 06/23/14.
  31 //
  32
  33 #include <stdio.h>
  34 #include <sys/types.h>
  35 #include <sys/socket.h>
  36 #include <netdb.h>
  37 #include <sys/errno.h>
  38 #include <sys/sys_domain.h>
  39 #include <sys/ioctl.h>
  40 #include <sys/kern_control.h>
  41 #include <sys/queue.h>
  42 #include <netinet/in.h>
  43 #include <stdio.h>
  44 #include <err.h>
  45 #include <string.h>
  46 #include <stdlib.h>
  47 #include <unistd.h>
  48 #include <ctype.h>
  49 #include <sysexits.h>
  50 #include <net/packet_mangler.h>
  51
  52
  53 #define BUF_MAX 1000
  54 int doit();
  55
  56 Pkt_Mnglr_Flow dir = INOUT;
  57 struct addrinfo * p_localaddr = NULL;
  58 struct addrinfo * p_remoteaddr = NULL;
  59 struct sockaddr_storage l_saddr = {0};
  60 struct sockaddr_storage r_saddr = {0};
  61
  62 int sf = -1;
  63 uint32_t duration  = 0;
  64 uint32_t protocol = 0;
  65 uint32_t proto_act_mask = 0;
  66 uint32_t ip_act_mask = 0;
  67 uint16_t local_port = 0;
  68 uint16_t remote_port = 0;
  69 uint8_t activate = 1;
  70
  71 static const char *
  72 basename(const char * str)
  73 {
  74     const char *last_slash = strrchr(str, '/');
  75
  76     if (last_slash == NULL)
  77         return (str);
  78     else
  79         return (last_slash + 1);
  80 }
  81
  82 struct option_desc {
  83     const char *option;
  84     const char *description;
  85     int required;
  86 };
  87
  88 struct option_desc option_desc_list[] = {
  89     { "-h ", "Help", 0 },
  90     { "-f flow", "flow direction to apply mangler on. Values can be: in/out/inout. default is inout", 0 },
  91     { "-l IP address ", "Local IP we are interested in ", 0 },
  92     { "-r IP address ", "Remote IP we are interested in", 0 },
  93     { "-m IP action mask ", "IP action mask", 0 },
  94     { "-t time", "Run duration for which packet mangler will run. A value of 0 means forever (till program is killed).", 0 },
  95     { "-p IP Protocol ", "IP protocol i.e. one of tcp, udp, icmp, icmpv6", 0 },
  96     { "-L Local port ", "Local port", 0 },
  97     { "-R Remote port ", "Remote port", 0 },
  98     { "-M Protocol action mask ", "Protocol action mask", 0 },
  99     { NULL, NULL, 0 }  /* Mark end of list */
 100 };
 101
 102
 103 static void
 104 usage(const char *cmd)
 105 {
 106     struct option_desc *option_desc;
 107     char * usage_str = (char *)malloc(BUF_MAX);
 108     size_t usage_len;
 109
 110     if (usage_str == NULL)
 111         err(1, "%s: malloc(%d)", __func__, BUF_MAX);
 112
 113     usage_len = snprintf(usage_str, BUF_MAX, "# usage: %s ", basename(cmd));
 114
 115     for (option_desc = option_desc_list; option_desc->option != NULL; option_desc++) {
 116         int len;
 117
 118         if (option_desc->required)
 119             len = snprintf(usage_str + usage_len, BUF_MAX - usage_len, "%s ", option_desc->option);
 120         else
 121             len = snprintf(usage_str + usage_len, BUF_MAX - usage_len, "[%s] ", option_desc->option);
 122         if (len < 0)
 123             err(1, "%s: snprintf(", __func__);
 124
 125         usage_len += len;
 126         if (usage_len > BUF_MAX)
 127             break;
 128     }
 129     printf("%s\n", usage_str);
 130     printf("options:\n");
 131
 132     for (option_desc = option_desc_list; option_desc->option != NULL; option_desc++) {
 133         printf(" %-20s # %s\n", option_desc->option, option_desc->description);
 134     }
 135
 136 }
 137
 138 int
 139 main(int argc, char * const argv[]) {
 140     int ch;
 141     int error;
 142
 143     if (argc == 1) {
 144         usage(argv[0]);
 145         exit(0);
 146     }
 147
 148     while ((ch = getopt(argc, argv, "hf:l:r:t:p:m:M:L:R:")) != -1) {
 149         switch (ch) {
 150             case 'h':
 151                 usage(argv[0]);
 152                 exit(0);
 153                 break;
 154             case 'f': {
 155                 if (strcasecmp(optarg, "in") == 0) {
 156                     dir = IN;
 157                 } else if (strcasecmp(optarg, "out") == 0) {
 158                     dir = OUT;
 159                 } else if (strcasecmp(optarg, "inout") == 0) {
 160                     dir = INOUT;
 161                 } else {
 162                     usage(argv[0]);
 163                     errx(1, "syntax error");
 164                 }
 165             }
 166                 break;
 167             case 'l':
 168                 if ((error = getaddrinfo(optarg, NULL, NULL, &p_localaddr)))
 169                     errx(1, "getaddrinfo returned error: %s", gai_strerror(error));
 170
 171                 break;
 172             case 'r':
 173                 if ((error = getaddrinfo(optarg, NULL, NULL, &p_remoteaddr)))
 174                     errx(1, "getaddrinfo returned error: %s", gai_strerror(error));
 175
 176                 break;
 177             case 'm':
 178                 ip_act_mask = (uint32_t)atoi(optarg);
 179                 break;
 180             case 't':
 181                 duration = (uint32_t)atoi(optarg);
 182                 break;
 183             case 'p':
 184                 /* Only support tcp for now */
 185                 if (strcasecmp(optarg, "tcp") == 0) {
 186                     protocol = IPPROTO_TCP;
 187                 } else if (strcasecmp(optarg, "udp") == 0) {
 188                     protocol = IPPROTO_UDP;
 189                     errx(1, "Protocol not supported.");
 190                 } else if (strcasecmp(optarg, "icmp") == 0) {
 191                     protocol = IPPROTO_ICMP;
 192                     errx(1, "Protocol not supported.");
 193                 } else if (strcasecmp(optarg, "icmpv6") == 0) {
 194                     protocol = IPPROTO_ICMPV6;
 195                     errx(1, "Protocol not supported.");
 196                 } else {
 197                     errx(1, "Protocol not supported.");
 198                 }
 199                 break;
 200
 201             case 'L':
 202                 local_port = htons((uint16_t)atoi(optarg));
 203                 break;
 204             case 'R':
 205                 remote_port = htons((uint16_t)atoi(optarg));
 206                 break;
 207             case 'M':
 208                 proto_act_mask = (uint32_t)atoi(optarg);
 209                 break;
 210
 211             default:
 212                 warnx("# syntax error, unknow option '%d'", ch);
 213                 usage(argv[0]);
 214                 exit(0);
 215         }
 216     }
 217
 218     if (p_localaddr && p_remoteaddr) {
 219         if (p_localaddr->ai_family!=p_remoteaddr->ai_family) {
 220             errx(1, "The address families for local and remote address"
 221                  " when both present, must be equal");
 222         }
 223     }
 224
 225
 226     doit();
 227
 228     return (0);
 229 }
 230
 231
 232 int
 233 doit()
 234 {
 235     struct sockaddr_ctl addr;
 236
 237     sf = socket(PF_SYSTEM, SOCK_DGRAM, SYSPROTO_CONTROL);
 238     if (sf == -1) {
 239         err(1, "socket()");
 240     }
 241
 242     /* Connect the socket */
 243     bzero(&addr, sizeof(addr));
 244     addr.sc_len = sizeof(addr);
 245     addr.sc_family = AF_SYSTEM;
 246     addr.ss_sysaddr = AF_SYS_CONTROL;
 247
 248     {
 249         struct ctl_info info;
 250         memset(&info, 0, sizeof(info));
 251         strncpy(info.ctl_name, PACKET_MANGLER_CONTROL_NAME, sizeof(info.ctl_name));
 252         if (ioctl(sf, CTLIOCGINFO, &info)) {
 253             perror("Could not get ID for kernel control.\n");
 254             exit(-1);
 255         }
 256         addr.sc_id = info.ctl_id;
 257         addr.sc_unit = 1;
 258     }
 259
 260     if (connect(sf, (struct sockaddr *)&addr, sizeof(struct sockaddr_ctl)) == -1) {
 261         err(1, "connect()");
 262     }
 263
 264     if (setsockopt(sf, SYSPROTO_CONTROL, PKT_MNGLR_OPT_DIRECTION,
 265                    &dir, sizeof(uint32_t)) == -1) {
 266         err(1, "setsockopt could not set direction.");
 267     }
 268
 269     /* Set the IP addresses for the flow */
 270     if (p_localaddr) {
 271         l_saddr = *((struct sockaddr_storage *)(p_localaddr->ai_addr));
 272
 273         if (setsockopt(sf, SYSPROTO_CONTROL, PKT_MNGLR_OPT_LOCAL_IP,
 274                        &l_saddr, sizeof(struct sockaddr_storage)) == -1) {
 275             err(1, "setsockopt could not set local address.");
 276         }
 277         freeaddrinfo(p_localaddr);
 278         p_localaddr = NULL;
 279     }
 280
 281     if (p_remoteaddr) {
 282         r_saddr = *((struct sockaddr_storage *)(p_remoteaddr->ai_addr));
 283
 284         if (setsockopt(sf, SYSPROTO_CONTROL, PKT_MNGLR_OPT_REMOTE_IP,
 285                        &r_saddr, sizeof(struct sockaddr_storage)) == -1) {
 286             err(1, "setsockopt could not set remote address.");
 287         }
 288         freeaddrinfo(p_remoteaddr);
 289         p_remoteaddr = NULL;
 290     }
 291
 292     /* Set ports for the flow */
 293     if (local_port && (setsockopt(sf, SYSPROTO_CONTROL, PKT_MNGLR_OPT_LOCAL_PORT,
 294                                   &local_port, sizeof(uint16_t)) == -1)) {
 295         err(1, "setsockopt could not set local port.");
 296
 297     }
 298
 299     if (remote_port && (setsockopt(sf, SYSPROTO_CONTROL, PKT_MNGLR_OPT_REMOTE_PORT,
 300                                    &remote_port, sizeof(uint16_t)) == -1)) {
 301         err(1, "setsockopt could not set remote port.");
 302
 303     }
 304
 305     if (protocol && setsockopt(sf, SYSPROTO_CONTROL, PKT_MNGLR_OPT_PROTOCOL,
 306                                &protocol, sizeof(uint32_t)) == -1) {
 307         err(1, "setsockopt could not set protocol.");
 308     }
 309
 310     if (proto_act_mask &&
 311         (setsockopt(sf, SYSPROTO_CONTROL, PKT_MNGLR_OPT_PROTO_ACT_MASK,
 312                     &proto_act_mask, sizeof(uint32_t))==-1)) {
 313         err(1, "setsockopt could not set protocol action mask.");
 314     }
 315
 316     if (setsockopt(sf, SYSPROTO_CONTROL, PKT_MNGLR_OPT_ACTIVATE,
 317                    &activate, sizeof(uint8_t))== -1) {
 318         err(1, "setsockopt could not activate packet mangler.");
 319     }
 320
 321     if (!duration) {
 322         pause();
 323     } else {
 324         sleep(duration);
 325     }
 326
 327     close(sf);
 328     return 0;
 329 }