ppc/cegw-ppc/cegw.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <libgen.h>
   4 #include <string.h>
   5 #include <getopt.h>
   6 #include <errno.h>
   7 #include <sys/socket.h>
   8 #include <net/if.h>
   9 //#include <libnetlink.h>
  10 #include <linux/netlink.h>
  11 #include <linux/rtnetlink.h>
  12 #include <arpa/inet.h>
  13 #include <linux/can.h>
  14 #include <linux/types.h>
  15 #include <unistd.h>
  16 #include "canethgw.h"
  17
  18 /**
  19  * ToDo:
  20  * [ ] print usage, on -h and plain execution
  21  * [ ] start/stop listening
  22  * [ ] split to files
  23  */
  24
  25 #define CEGW_CMD_ADD     1
  26 #define CEGW_CMD_LIST    2
  27 #define CEGW_CMD_FLUSH   4
  28 #define CEGW_CMD_LISTEN  8
  29
  30 /* PowerPC encore */
  31 #define RTCAN_RTA(r)  ((struct rtattr*)(((char*)(r)) + NLMSG_ALIGN(sizeof(struct rtcanmsg))))
  32 #define RTCAN_PAYLOAD(n) NLMSG_PAYLOAD(n,sizeof(struct rtcanmsg))
  33
  34 /* some netlink helpers stolen from iproute2 package */
  35 #define NLMSG_TAIL(nmsg) \
  36         ((struct rtattr *)(((void *) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))
  37 #define AF_CAN 29
  38
  39 int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data,
  40               int alen)
  41 {
  42         int len = RTA_LENGTH(alen);
  43         struct rtattr *rta;
  44
  45         if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) {
  46                 fprintf(stderr, "addattr_l: message exceeded bound of %d\n",
  47                         maxlen);
  48                 return -1;
  49         }
  50         rta = NLMSG_TAIL(n);
  51         rta->rta_type = type;
  52         rta->rta_len = len;
  53         memcpy(RTA_DATA(rta), data, alen);
  54         n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
  55         return 0;
  56 }
  57
  58 int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
  59 {
  60         return addattr_l(n, maxlen, type, &data, sizeof(__u32));
  61 }
  62
  63 enum
  64 {
  65         IF_UNDEF,
  66         IF_CAN,
  67         IF_ETH_UDP
  68 };
  69
  70 struct cegw_data
  71 {
  72         int content;
  73         int src_if, dst_if;
  74         int can_ifidx;
  75         struct in_addr eth_addr;
  76         unsigned short eth_port;
  77         struct in_addr eth_listen_addr;
  78         unsigned short eth_listen_port;
  79 };
  80
  81 struct cegw_nlmsg
  82 {
  83         struct nlmsghdr nh;
  84         struct rtmsg rt;
  85         char buf[768]; /* enough? */
  86 };
  87
  88 struct list_item
  89 {
  90         int type;
  91         int can;
  92         struct in_addr ip;
  93         unsigned short port;
  94 };
  95
  96 unsigned int cegw_errno = 0;
  97
  98 enum
  99 {
 100         CEGW_ERR_UNKNOWN,
 101         CEGW_ERR_IF_UNSPEC,
 102         CEGW_ERR_IF_SAME,
 103         CEGW_ERR_IF_TYPE,
 104         CEGW_ERR_IF_CAN,
 105         CEGW_ERR_IF_ETH,
 106         CEGW_ERR_COLON,
 107         CEGW_ERR_ATON,
 108         CEGW_ERR_PORT
 109 };
 110
 111 char* cegw_errlist[] =
 112 {
 113         [ CEGW_ERR_UNKNOWN   ] = "",
 114         [ CEGW_ERR_IF_UNSPEC ] = "source or destination not specified",
 115         [ CEGW_ERR_IF_SAME   ] = "source and destination have same interface type",
 116         [ CEGW_ERR_IF_TYPE   ] = "unknown interface type",
 117         [ CEGW_ERR_IF_CAN    ] = "invalid can interface",
 118         [ CEGW_ERR_IF_ETH    ] = "invalid eth interface",
 119         [ CEGW_ERR_COLON     ] = "expected ':' (<ip>:<port>)",
 120         [ CEGW_ERR_ATON      ] = "ip address mismatch",
 121         [ CEGW_ERR_PORT      ] = "port number"
 122 };
 123
 124 static void perr( char* s )
 125 {
 126         if( s )
 127         {
 128                 if( cegw_errno == 0 )
 129                 {
 130                         fprintf( stderr, "error: %s\n", s );
 131
 132                 } else
 133                 {
 134                         fprintf( stderr, "error: %s, %s\n", s,
 135                                  cegw_errlist[ cegw_errno ] );
 136                 }
 137                 return;
 138         }
 139
 140         fprintf( stderr, "error: %s\n", cegw_errlist[ cegw_errno ] );
 141 }
 142
 143 /**
 144  * read_addrport - parses @in for eth address.
 145  * Valid input is e.g. udp@127.0.0.1:10502 or can@vcan0.
 146  *
 147  * @param[in]  in   string to search in
 148  * @param[out] addr ip address
 149  * @param[out] port transport layer port
 150  * @return 0 on success, -1 otherwise
 151  */
 152 int read_addrport( char* in, struct in_addr* addr, unsigned short* port )
 153 {
 154         char* delim = NULL;
 155         char addrstr[16];
 156         int addrlen;
 157
 158         if( (delim = strchr( in, ':' )) == NULL )
 159         {
 160                 cegw_errno = CEGW_ERR_COLON;
 161                 return -1;
 162         }
 163
 164         /* get address */
 165         /* ToDo: overflow */
 166         addrlen = delim - in;
 167         memcpy( addrstr, in, addrlen );
 168         addrstr[addrlen] = '\0';
 169         if( inet_aton( addrstr, addr ) == 0 )
 170         {
 171                 cegw_errno = CEGW_ERR_ATON;
 172                 return -1;
 173         }
 174
 175         /* get port */
 176         if( sscanf( delim, ":%hu", port ) != 1 ) /* ToDo: handle overflow */
 177         {
 178                 cegw_errno = CEGW_ERR_PORT;
 179                 return -1;
 180         }
 181
 182         return 0;
 183 }
 184
 185 /**
 186  * read_iftype - reads @in for iftype
 187  * Iftype type is e.g. "can@" or "udp@".
 188  *
 189  * @param[in] in string to search in
 190  * @param[out] iftype iftype detected
 191  * @return pointer to @in after iftype on success, NULL otherwise
 192  */
 193 char* read_iftype( char* in, int* iftype )
 194 {
 195         char* ret = in+4;
 196
 197         if( strncmp( "udp@", optarg, 4 ) == 0 )
 198         {
 199                 *iftype = IF_ETH_UDP;
 200                 return ret;
 201         }
 202         /*
 203         if( strncmp( "tcp@", optarg, 4 ) == 0 )
 204         {
 205                 return NULL;
 206         }
 207         */
 208         if( strncmp( "can@", optarg, 4 ) == 0 )
 209         {
 210                 *iftype = IF_CAN;
 211                 return ret;
 212         }
 213
 214         cegw_errno = CEGW_ERR_IF_TYPE;
 215         return NULL;
 216 }
 217
 218 /* ToDo: move to common */
 219
 220 /**
 221  * read_if - reads interface from @in
 222  * Function analyzes @in for interface specification in format
 223  * <if>@<ip>:<port>, where <if> is can or udp, <ip> is address in dotted
 224  * format
 225  *
 226  * @param[in]  in string to search in
 227  * @param[out] iftype interface type (IF_CAN or IF_ETH_UDP)
 228  * @param[out] d ip and port is stored to @d
 229  */
 230 int read_if( char* in, int* iftype, struct cegw_data* d )
 231 {
 232         char* optstr = NULL;
 233
 234         if( (optstr = read_iftype( in, iftype )) == NULL )
 235         {
 236                 return -1;
 237         }
 238
 239         switch( *iftype )
 240         {
 241                 case IF_CAN:
 242                         d->can_ifidx = if_nametoindex( optstr );
 243                         if( d->can_ifidx == 0 )
 244                         {
 245                                 cegw_errno = CEGW_ERR_IF_CAN;
 246                                 return -1;
 247                         }
 248                         break;
 249                 case IF_ETH_UDP:
 250                         if( read_addrport( optstr, &d->eth_addr, &d->eth_port ) != 0 )
 251                         {
 252                                 return -1;
 253                         }
 254                         break;
 255                 default:
 256                         return -1;
 257                         break;
 258         }
 259
 260         return 0;
 261 }
 262
 263 inline static int cegw_add( struct cegw_nlmsg* req, struct cegw_data* d )
 264 {
 265         int gwtype = 0;
 266
 267         req->nh.nlmsg_type  = RTM_NEWROUTE;
 268         if( (d->src_if == 0 || d->dst_if == 0) )
 269         {
 270                 cegw_errno = CEGW_ERR_IF_UNSPEC;
 271                 return -cegw_errno;
 272         }
 273
 274         if( d->src_if == d->dst_if )
 275         {
 276                 cegw_errno = CEGW_ERR_IF_SAME;
 277                 return -cegw_errno;
 278         }
 279
 280         gwtype = (d->src_if == IF_CAN) ? CEGW_RULE_CAN_ETH : CEGW_RULE_ETH_CAN;
 281         addattr_l( &req->nh, sizeof(*req), CEGW_CAN_IFINDEX, &d->can_ifidx, sizeof(d->can_ifidx) );
 282         addattr_l( &req->nh, sizeof(*req), CEGW_ETH_IP, &d->eth_addr, sizeof(d->eth_addr) );
 283         addattr_l( &req->nh, sizeof(*req), CEGW_ETH_PORT, &d->eth_port, sizeof(d->eth_port) );
 284         addattr32( &req->nh, sizeof(*req), CEGW_CMD_INFO, gwtype );
 285
 286         return 0;
 287 }
 288
 289 inline static int cegw_listen( struct cegw_nlmsg* req, struct cegw_data* d )
 290 {
 291         req->nh.nlmsg_type = RTM_NEWROUTE;
 292         addattr32( &req->nh, sizeof(*req), CEGW_CMD_INFO, CEGW_LISTEN );
 293         addattr_l( &req->nh, sizeof(*req), CEGW_ETH_IP, &d->eth_listen_addr, sizeof(d->eth_listen_addr) );
 294         addattr_l( &req->nh, sizeof(*req), CEGW_ETH_PORT, &d->eth_listen_port, sizeof(d->eth_listen_port) );
 295
 296         return 0;
 297 }
 298
 299 inline static int cegw_list( struct cegw_nlmsg* req, struct cegw_data* d )
 300 {
 301         req->nh.nlmsg_type = RTM_GETROUTE;
 302         req->nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
 303
 304         return 0;
 305 }
 306
 307 inline static int cegw_flush( struct cegw_nlmsg* req, struct cegw_data* d )
 308 {
 309         addattr32( &req->nh, sizeof(*req), CEGW_CMD_INFO, CEGW_FLUSH );
 310         req->nh.nlmsg_type  = RTM_DELROUTE;
 311         return 0;
 312 }
 313
 314 void print_list_item( struct list_item* li )
 315 {
 316         char ifname[IF_NAMESIZE];
 317         const char src_width = 21;
 318         char* dotaddr;
 319         int tmp;
 320
 321         if( if_indextoname( li->can, ifname ) == NULL )
 322         {
 323                 strncpy( ifname, "unknown", IF_NAMESIZE );
 324         }
 325
 326         /* ToDo listening at */
 327         switch( li->type )
 328         {
 329                 case CEGW_RULE_CAN_ETH:
 330                         printf( "can@%-*s -> udp@%s:%hu\n", src_width, ifname, \
 331                                  inet_ntoa(li->ip), li->port );
 332                         break;
 333                 case CEGW_RULE_ETH_CAN:
 334                         dotaddr = inet_ntoa(li->ip);
 335                         tmp = src_width - strlen(dotaddr) - 1;
 336                         printf( "udp@%s:%-*hu -> can@%s\n", inet_ntoa(li->ip), \
 337                                  tmp, li->port, ifname );
 338                         break;
 339         }
 340 }
 341
 342 int main( int argc, char* argv[] )
 343 {
 344         int s;
 345         int tmp = 0;
 346         int cmd = 0;
 347         char* optstr;
 348         char opt;
 349         struct sockaddr_nl nladdr;
 350         int err = 0;
 351         struct cegw_nlmsg req;
 352         struct cegw_data d;
 353         char rxbuf[8192]; /* ToDo: /linux/netlink.h? */
 354         int rsize = 0;
 355         struct nlmsghdr* nlh;
 356         struct nlmsgerr* rte;
 357         struct rtattr* rta;
 358         int len;
 359         struct list_item li;
 360
 361         memset( &d, 0, sizeof(d) );
 362
 363         struct option long_opt[] =
 364         {
 365                 { "add"   , 0, NULL, 'A' },
 366                 { "flush" , 0, NULL, 'F' },
 367                 { "list"  , 0, NULL, 'L' },
 368                 { "listen", 1, NULL, 'l' },
 369                 { 0, 0, 0, 0 }
 370         };
 371
 372         while( 1 )
 373         {
 374                 opt = getopt_long( argc, argv, "AFLl:s:d:", long_opt, NULL );
 375                 if( opt == -1 )
 376                         break;
 377
 378                 //printf( "optarg=%s\n", optarg );
 379                 switch( opt )
 380                 {
 381                         case 'A':
 382                                 cmd |= CEGW_CMD_ADD;
 383                                 break;
 384                         case 'F':
 385                                 cmd |= CEGW_CMD_FLUSH;
 386                                 break;
 387                         case 'L':
 388                                 cmd |= CEGW_CMD_LIST;
 389                                 break;
 390                         case 'l':
 391                                 cmd |= CEGW_CMD_LISTEN;
 392                                 if( (optstr = read_iftype( optarg, &tmp )) == NULL )
 393                                 {
 394                                         perr( "'--listen'" );
 395                                         return -1;
 396                                 }
 397                                 if( tmp != IF_ETH_UDP )
 398                                 {
 399                                         perr( "'--listen' expects udp interface" );
 400                                         return -1;
 401                                 }
 402                                 if( read_addrport( optstr, &d.eth_listen_addr, &d.eth_listen_port ) )
 403                                 {
 404                                         perr( "'--listen'" );
 405                                         return -1;
 406                                 }
 407                                 break;
 408                         case 's':
 409                                 if( read_if( optarg, &d.src_if, &d ) != 0 )
 410                                 {
 411                                         perr( "'-s'" );
 412                                         return -1;
 413                                 }
 414                                 break;
 415                         case 'd':
 416                                 if( read_if( optarg, &d.dst_if, &d ) != 0 )
 417                                 {
 418                                         perr( "'-d'" );
 419                                         return -1;
 420                                 }
 421                                 break;
 422                         case '?':
 423                                 return -1;
 424                                 break;
 425                         default:
 426                                 //fprintf( stderr, "unknown option: %u\n", opt );
 427                                 goto while_break;
 428                                 //return -1;
 429                                 break;
 430                 }
 431         }
 432
 433         while_break:
 434
 435         /* prepare netlink message */
 436         req.nh.nlmsg_len   = NLMSG_LENGTH( sizeof(struct rtmsg) );
 437         //req.nh.nlmsg_type;
 438         req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
 439         req.nh.nlmsg_seq   = 0;
 440         req.nh.nlmsg_pid   = 0; /* ? */
 441
 442         memset( &req.rt, 0, sizeof(req.rt) );
 443         req.rt.rtm_family = AF_CAN;
 444
 445         switch( cmd )
 446         {
 447                 case 0:
 448                         perr( "command not specified" );
 449                         return -1;
 450                         break;
 451                 case CEGW_CMD_ADD:
 452                         if( cegw_add( &req, &d ) != 0 )
 453                         {
 454                                 perr( "'--add'" );
 455                                 return -1;
 456                         }
 457                         break;
 458                 case CEGW_CMD_FLUSH:
 459                         cegw_flush( &req, &d );
 460                         break;
 461                 case CEGW_CMD_LIST:
 462                         cegw_list( &req, &d );
 463                         break;
 464                 case CEGW_CMD_LISTEN:
 465                         cegw_listen( &req, &d );
 466                         break;
 467                 default:
 468                         perr( "command mismatch" );
 469                         break;
 470         }
 471
 472         /* send over netlink socket */
 473         s = socket( PF_NETLINK, SOCK_RAW, NETLINK_ROUTE ); /* chck */
 474
 475         memset( &nladdr, 0, sizeof(nladdr) );
 476         nladdr.nl_family = AF_NETLINK;
 477         nladdr.nl_pad = 0;
 478         nladdr.nl_pid = 0;
 479         nladdr.nl_groups = 0;
 480
 481         err = sendto( s, &req, req.nh.nlmsg_len, 0,
 482                       (struct sockaddr*)&nladdr, sizeof(nladdr) );
 483         if( err < 0 )
 484         {
 485                 perror( "netlink sendto" );
 486                 return -1;
 487         }
 488
 489         /* recv */
 490         rsize = recv( s, &rxbuf, sizeof(rxbuf), 0 );
 491         if( rsize < 0 )
 492         {
 493                 perr( "recv" );
 494                 return -1;
 495         }
 496         nlh = (struct nlmsghdr*)rxbuf;
 497
 498         if( nlh->nlmsg_type == NLMSG_ERROR )
 499         {
 500                 rte = (struct nlmsgerr*)NLMSG_DATA( nlh );
 501                 err = rte->error;
 502
 503                 if( err == 0  )
 504                 {
 505                         printf( "%s\n", strerror(abs(err)) );
 506                         return 0;
 507                 } else
 508                 {
 509                         printf( "netlink error: %s\n", strerror(abs(err)) );
 510                         return -1;
 511                 }
 512         }
 513
 514         if( cmd & CEGW_CMD_LIST )
 515         {
 516                 /* ToDo recv while */
 517                 printf( "%10ssource%20sdestination\n", "", "" );
 518                 while( 1 )
 519                 {
 520                         if( !NLMSG_OK( nlh, rsize ) )
 521                         {
 522                                 break;
 523                         }
 524                         if( nlh->nlmsg_type == NLMSG_DONE )
 525                         {
 526                                 break;
 527                         }
 528                         /* ToDo: NLMSG_ERR */
 529                         rta = NLMSG_DATA( nlh );
 530                         len = NLMSG_PAYLOAD( nlh, 0 );
 531                         for( ;RTA_OK(rta, len); rta = RTA_NEXT(rta,len) )
 532                         {
 533                                 switch( rta->rta_type )
 534                                 {
 535                                         case CEGW_TYPE:
 536                                                 li.type = *(int*)RTA_DATA(rta);
 537                                                 break;
 538                                         case CEGW_CAN_IFINDEX:
 539                                                 li.can = *(int*)RTA_DATA(rta);
 540                                                 break;
 541                                         case CEGW_ETH_IP:
 542                                                 li.ip = *(struct in_addr*)RTA_DATA(rta);
 543                                                 break;
 544                                         case CEGW_ETH_PORT:
 545                                                 li.port = *(unsigned short*)RTA_DATA(rta);
 546                                                 break;
 547                                         /* case CGW_ETH_PROTO */
 548                                 }
 549                         }
 550
 551                         print_list_item( &li );
 552
 553                         nlh = NLMSG_NEXT( nlh, rsize );
 554                 }
 555         }
 556
 557         return 0;
 558 }
 559