~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/netfilter/nf_conntrack_proto_dccp.c

Version: ~ [ linux-5.4-rc3 ] ~ [ linux-5.3.6 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.79 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.149 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.196 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.196 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.75 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * DCCP connection tracking protocol helper
  3  *
  4  * Copyright (c) 2005, 2006, 2008 Patrick McHardy <kaber@trash.net>
  5  *
  6  * This program is free software; you can redistribute it and/or modify
  7  * it under the terms of the GNU General Public License version 2 as
  8  * published by the Free Software Foundation.
  9  *
 10  */
 11 #include <linux/kernel.h>
 12 #include <linux/module.h>
 13 #include <linux/init.h>
 14 #include <linux/sysctl.h>
 15 #include <linux/spinlock.h>
 16 #include <linux/skbuff.h>
 17 #include <linux/dccp.h>
 18 #include <linux/slab.h>
 19 
 20 #include <net/net_namespace.h>
 21 #include <net/netns/generic.h>
 22 
 23 #include <linux/netfilter/nfnetlink_conntrack.h>
 24 #include <net/netfilter/nf_conntrack.h>
 25 #include <net/netfilter/nf_conntrack_l4proto.h>
 26 #include <net/netfilter/nf_conntrack_ecache.h>
 27 #include <net/netfilter/nf_log.h>
 28 
 29 /* Timeouts are based on values from RFC4340:
 30  *
 31  * - REQUEST:
 32  *
 33  *   8.1.2. Client Request
 34  *
 35  *   A client MAY give up on its DCCP-Requests after some time
 36  *   (3 minutes, for example).
 37  *
 38  * - RESPOND:
 39  *
 40  *   8.1.3. Server Response
 41  *
 42  *   It MAY also leave the RESPOND state for CLOSED after a timeout of
 43  *   not less than 4MSL (8 minutes);
 44  *
 45  * - PARTOPEN:
 46  *
 47  *   8.1.5. Handshake Completion
 48  *
 49  *   If the client remains in PARTOPEN for more than 4MSL (8 minutes),
 50  *   it SHOULD reset the connection with Reset Code 2, "Aborted".
 51  *
 52  * - OPEN:
 53  *
 54  *   The DCCP timestamp overflows after 11.9 hours. If the connection
 55  *   stays idle this long the sequence number won't be recognized
 56  *   as valid anymore.
 57  *
 58  * - CLOSEREQ/CLOSING:
 59  *
 60  *   8.3. Termination
 61  *
 62  *   The retransmission timer should initially be set to go off in two
 63  *   round-trip times and should back off to not less than once every
 64  *   64 seconds ...
 65  *
 66  * - TIMEWAIT:
 67  *
 68  *   4.3. States
 69  *
 70  *   A server or client socket remains in this state for 2MSL (4 minutes)
 71  *   after the connection has been town down, ...
 72  */
 73 
 74 #define DCCP_MSL (2 * 60 * HZ)
 75 
 76 static const char * const dccp_state_names[] = {
 77         [CT_DCCP_NONE]          = "NONE",
 78         [CT_DCCP_REQUEST]       = "REQUEST",
 79         [CT_DCCP_RESPOND]       = "RESPOND",
 80         [CT_DCCP_PARTOPEN]      = "PARTOPEN",
 81         [CT_DCCP_OPEN]          = "OPEN",
 82         [CT_DCCP_CLOSEREQ]      = "CLOSEREQ",
 83         [CT_DCCP_CLOSING]       = "CLOSING",
 84         [CT_DCCP_TIMEWAIT]      = "TIMEWAIT",
 85         [CT_DCCP_IGNORE]        = "IGNORE",
 86         [CT_DCCP_INVALID]       = "INVALID",
 87 };
 88 
 89 #define sNO     CT_DCCP_NONE
 90 #define sRQ     CT_DCCP_REQUEST
 91 #define sRS     CT_DCCP_RESPOND
 92 #define sPO     CT_DCCP_PARTOPEN
 93 #define sOP     CT_DCCP_OPEN
 94 #define sCR     CT_DCCP_CLOSEREQ
 95 #define sCG     CT_DCCP_CLOSING
 96 #define sTW     CT_DCCP_TIMEWAIT
 97 #define sIG     CT_DCCP_IGNORE
 98 #define sIV     CT_DCCP_INVALID
 99 
100 /*
101  * DCCP state transition table
102  *
103  * The assumption is the same as for TCP tracking:
104  *
105  * We are the man in the middle. All the packets go through us but might
106  * get lost in transit to the destination. It is assumed that the destination
107  * can't receive segments we haven't seen.
108  *
109  * The following states exist:
110  *
111  * NONE:        Initial state, expecting Request
112  * REQUEST:     Request seen, waiting for Response from server
113  * RESPOND:     Response from server seen, waiting for Ack from client
114  * PARTOPEN:    Ack after Response seen, waiting for packet other than Response,
115  *              Reset or Sync from server
116  * OPEN:        Packet other than Response, Reset or Sync seen
117  * CLOSEREQ:    CloseReq from server seen, expecting Close from client
118  * CLOSING:     Close seen, expecting Reset
119  * TIMEWAIT:    Reset seen
120  * IGNORE:      Not determinable whether packet is valid
121  *
122  * Some states exist only on one side of the connection: REQUEST, RESPOND,
123  * PARTOPEN, CLOSEREQ. For the other side these states are equivalent to
124  * the one it was in before.
125  *
126  * Packets are marked as ignored (sIG) if we don't know if they're valid
127  * (for example a reincarnation of a connection we didn't notice is dead
128  * already) and the server may send back a connection closing Reset or a
129  * Response. They're also used for Sync/SyncAck packets, which we don't
130  * care about.
131  */
132 static const u_int8_t
133 dccp_state_table[CT_DCCP_ROLE_MAX + 1][DCCP_PKT_SYNCACK + 1][CT_DCCP_MAX + 1] = {
134         [CT_DCCP_ROLE_CLIENT] = {
135                 [DCCP_PKT_REQUEST] = {
136                 /*
137                  * sNO -> sRQ           Regular Request
138                  * sRQ -> sRQ           Retransmitted Request or reincarnation
139                  * sRS -> sRS           Retransmitted Request (apparently Response
140                  *                      got lost after we saw it) or reincarnation
141                  * sPO -> sIG           Ignore, conntrack might be out of sync
142                  * sOP -> sIG           Ignore, conntrack might be out of sync
143                  * sCR -> sIG           Ignore, conntrack might be out of sync
144                  * sCG -> sIG           Ignore, conntrack might be out of sync
145                  * sTW -> sRQ           Reincarnation
146                  *
147                  *      sNO, sRQ, sRS, sPO. sOP, sCR, sCG, sTW, */
148                         sRQ, sRQ, sRS, sIG, sIG, sIG, sIG, sRQ,
149                 },
150                 [DCCP_PKT_RESPONSE] = {
151                 /*
152                  * sNO -> sIV           Invalid
153                  * sRQ -> sIG           Ignore, might be response to ignored Request
154                  * sRS -> sIG           Ignore, might be response to ignored Request
155                  * sPO -> sIG           Ignore, might be response to ignored Request
156                  * sOP -> sIG           Ignore, might be response to ignored Request
157                  * sCR -> sIG           Ignore, might be response to ignored Request
158                  * sCG -> sIG           Ignore, might be response to ignored Request
159                  * sTW -> sIV           Invalid, reincarnation in reverse direction
160                  *                      goes through sRQ
161                  *
162                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
163                         sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIV,
164                 },
165                 [DCCP_PKT_ACK] = {
166                 /*
167                  * sNO -> sIV           No connection
168                  * sRQ -> sIV           No connection
169                  * sRS -> sPO           Ack for Response, move to PARTOPEN (8.1.5.)
170                  * sPO -> sPO           Retransmitted Ack for Response, remain in PARTOPEN
171                  * sOP -> sOP           Regular ACK, remain in OPEN
172                  * sCR -> sCR           Ack in CLOSEREQ MAY be processed (8.3.)
173                  * sCG -> sCG           Ack in CLOSING MAY be processed (8.3.)
174                  * sTW -> sIV
175                  *
176                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
177                         sIV, sIV, sPO, sPO, sOP, sCR, sCG, sIV
178                 },
179                 [DCCP_PKT_DATA] = {
180                 /*
181                  * sNO -> sIV           No connection
182                  * sRQ -> sIV           No connection
183                  * sRS -> sIV           No connection
184                  * sPO -> sIV           MUST use DataAck in PARTOPEN state (8.1.5.)
185                  * sOP -> sOP           Regular Data packet
186                  * sCR -> sCR           Data in CLOSEREQ MAY be processed (8.3.)
187                  * sCG -> sCG           Data in CLOSING MAY be processed (8.3.)
188                  * sTW -> sIV
189                  *
190                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
191                         sIV, sIV, sIV, sIV, sOP, sCR, sCG, sIV,
192                 },
193                 [DCCP_PKT_DATAACK] = {
194                 /*
195                  * sNO -> sIV           No connection
196                  * sRQ -> sIV           No connection
197                  * sRS -> sPO           Ack for Response, move to PARTOPEN (8.1.5.)
198                  * sPO -> sPO           Remain in PARTOPEN state
199                  * sOP -> sOP           Regular DataAck packet in OPEN state
200                  * sCR -> sCR           DataAck in CLOSEREQ MAY be processed (8.3.)
201                  * sCG -> sCG           DataAck in CLOSING MAY be processed (8.3.)
202                  * sTW -> sIV
203                  *
204                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
205                         sIV, sIV, sPO, sPO, sOP, sCR, sCG, sIV
206                 },
207                 [DCCP_PKT_CLOSEREQ] = {
208                 /*
209                  * CLOSEREQ may only be sent by the server.
210                  *
211                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
212                         sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV
213                 },
214                 [DCCP_PKT_CLOSE] = {
215                 /*
216                  * sNO -> sIV           No connection
217                  * sRQ -> sIV           No connection
218                  * sRS -> sIV           No connection
219                  * sPO -> sCG           Client-initiated close
220                  * sOP -> sCG           Client-initiated close
221                  * sCR -> sCG           Close in response to CloseReq (8.3.)
222                  * sCG -> sCG           Retransmit
223                  * sTW -> sIV           Late retransmit, already in TIME_WAIT
224                  *
225                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
226                         sIV, sIV, sIV, sCG, sCG, sCG, sIV, sIV
227                 },
228                 [DCCP_PKT_RESET] = {
229                 /*
230                  * sNO -> sIV           No connection
231                  * sRQ -> sTW           Sync received or timeout, SHOULD send Reset (8.1.1.)
232                  * sRS -> sTW           Response received without Request
233                  * sPO -> sTW           Timeout, SHOULD send Reset (8.1.5.)
234                  * sOP -> sTW           Connection reset
235                  * sCR -> sTW           Connection reset
236                  * sCG -> sTW           Connection reset
237                  * sTW -> sIG           Ignore (don't refresh timer)
238                  *
239                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
240                         sIV, sTW, sTW, sTW, sTW, sTW, sTW, sIG
241                 },
242                 [DCCP_PKT_SYNC] = {
243                 /*
244                  * We currently ignore Sync packets
245                  *
246                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
247                         sIG, sIG, sIG, sIG, sIG, sIG, sIG, sIG,
248                 },
249                 [DCCP_PKT_SYNCACK] = {
250                 /*
251                  * We currently ignore SyncAck packets
252                  *
253                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
254                         sIG, sIG, sIG, sIG, sIG, sIG, sIG, sIG,
255                 },
256         },
257         [CT_DCCP_ROLE_SERVER] = {
258                 [DCCP_PKT_REQUEST] = {
259                 /*
260                  * sNO -> sIV           Invalid
261                  * sRQ -> sIG           Ignore, conntrack might be out of sync
262                  * sRS -> sIG           Ignore, conntrack might be out of sync
263                  * sPO -> sIG           Ignore, conntrack might be out of sync
264                  * sOP -> sIG           Ignore, conntrack might be out of sync
265                  * sCR -> sIG           Ignore, conntrack might be out of sync
266                  * sCG -> sIG           Ignore, conntrack might be out of sync
267                  * sTW -> sRQ           Reincarnation, must reverse roles
268                  *
269                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
270                         sIV, sIG, sIG, sIG, sIG, sIG, sIG, sRQ
271                 },
272                 [DCCP_PKT_RESPONSE] = {
273                 /*
274                  * sNO -> sIV           Response without Request
275                  * sRQ -> sRS           Response to clients Request
276                  * sRS -> sRS           Retransmitted Response (8.1.3. SHOULD NOT)
277                  * sPO -> sIG           Response to an ignored Request or late retransmit
278                  * sOP -> sIG           Ignore, might be response to ignored Request
279                  * sCR -> sIG           Ignore, might be response to ignored Request
280                  * sCG -> sIG           Ignore, might be response to ignored Request
281                  * sTW -> sIV           Invalid, Request from client in sTW moves to sRQ
282                  *
283                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
284                         sIV, sRS, sRS, sIG, sIG, sIG, sIG, sIV
285                 },
286                 [DCCP_PKT_ACK] = {
287                 /*
288                  * sNO -> sIV           No connection
289                  * sRQ -> sIV           No connection
290                  * sRS -> sIV           No connection
291                  * sPO -> sOP           Enter OPEN state (8.1.5.)
292                  * sOP -> sOP           Regular Ack in OPEN state
293                  * sCR -> sIV           Waiting for Close from client
294                  * sCG -> sCG           Ack in CLOSING MAY be processed (8.3.)
295                  * sTW -> sIV
296                  *
297                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
298                         sIV, sIV, sIV, sOP, sOP, sIV, sCG, sIV
299                 },
300                 [DCCP_PKT_DATA] = {
301                 /*
302                  * sNO -> sIV           No connection
303                  * sRQ -> sIV           No connection
304                  * sRS -> sIV           No connection
305                  * sPO -> sOP           Enter OPEN state (8.1.5.)
306                  * sOP -> sOP           Regular Data packet in OPEN state
307                  * sCR -> sIV           Waiting for Close from client
308                  * sCG -> sCG           Data in CLOSING MAY be processed (8.3.)
309                  * sTW -> sIV
310                  *
311                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
312                         sIV, sIV, sIV, sOP, sOP, sIV, sCG, sIV
313                 },
314                 [DCCP_PKT_DATAACK] = {
315                 /*
316                  * sNO -> sIV           No connection
317                  * sRQ -> sIV           No connection
318                  * sRS -> sIV           No connection
319                  * sPO -> sOP           Enter OPEN state (8.1.5.)
320                  * sOP -> sOP           Regular DataAck in OPEN state
321                  * sCR -> sIV           Waiting for Close from client
322                  * sCG -> sCG           Data in CLOSING MAY be processed (8.3.)
323                  * sTW -> sIV
324                  *
325                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
326                         sIV, sIV, sIV, sOP, sOP, sIV, sCG, sIV
327                 },
328                 [DCCP_PKT_CLOSEREQ] = {
329                 /*
330                  * sNO -> sIV           No connection
331                  * sRQ -> sIV           No connection
332                  * sRS -> sIV           No connection
333                  * sPO -> sOP -> sCR    Move directly to CLOSEREQ (8.1.5.)
334                  * sOP -> sCR           CloseReq in OPEN state
335                  * sCR -> sCR           Retransmit
336                  * sCG -> sCR           Simultaneous close, client sends another Close
337                  * sTW -> sIV           Already closed
338                  *
339                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
340                         sIV, sIV, sIV, sCR, sCR, sCR, sCR, sIV
341                 },
342                 [DCCP_PKT_CLOSE] = {
343                 /*
344                  * sNO -> sIV           No connection
345                  * sRQ -> sIV           No connection
346                  * sRS -> sIV           No connection
347                  * sPO -> sOP -> sCG    Move direcly to CLOSING
348                  * sOP -> sCG           Move to CLOSING
349                  * sCR -> sIV           Close after CloseReq is invalid
350                  * sCG -> sCG           Retransmit
351                  * sTW -> sIV           Already closed
352                  *
353                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
354                         sIV, sIV, sIV, sCG, sCG, sIV, sCG, sIV
355                 },
356                 [DCCP_PKT_RESET] = {
357                 /*
358                  * sNO -> sIV           No connection
359                  * sRQ -> sTW           Reset in response to Request
360                  * sRS -> sTW           Timeout, SHOULD send Reset (8.1.3.)
361                  * sPO -> sTW           Timeout, SHOULD send Reset (8.1.3.)
362                  * sOP -> sTW
363                  * sCR -> sTW
364                  * sCG -> sTW
365                  * sTW -> sIG           Ignore (don't refresh timer)
366                  *
367                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW, sTW */
368                         sIV, sTW, sTW, sTW, sTW, sTW, sTW, sTW, sIG
369                 },
370                 [DCCP_PKT_SYNC] = {
371                 /*
372                  * We currently ignore Sync packets
373                  *
374                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
375                         sIG, sIG, sIG, sIG, sIG, sIG, sIG, sIG,
376                 },
377                 [DCCP_PKT_SYNCACK] = {
378                 /*
379                  * We currently ignore SyncAck packets
380                  *
381                  *      sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
382                         sIG, sIG, sIG, sIG, sIG, sIG, sIG, sIG,
383                 },
384         },
385 };
386 
387 /* this module per-net specifics */
388 static int dccp_net_id __read_mostly;
389 struct dccp_net {
390         struct nf_proto_net pn;
391         int dccp_loose;
392         unsigned int dccp_timeout[CT_DCCP_MAX + 1];
393 };
394 
395 static inline struct dccp_net *dccp_pernet(struct net *net)
396 {
397         return net_generic(net, dccp_net_id);
398 }
399 
400 static bool dccp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
401                               struct nf_conntrack_tuple *tuple)
402 {
403         struct dccp_hdr _hdr, *dh;
404 
405         dh = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
406         if (dh == NULL)
407                 return false;
408 
409         tuple->src.u.dccp.port = dh->dccph_sport;
410         tuple->dst.u.dccp.port = dh->dccph_dport;
411         return true;
412 }
413 
414 static bool dccp_invert_tuple(struct nf_conntrack_tuple *inv,
415                               const struct nf_conntrack_tuple *tuple)
416 {
417         inv->src.u.dccp.port = tuple->dst.u.dccp.port;
418         inv->dst.u.dccp.port = tuple->src.u.dccp.port;
419         return true;
420 }
421 
422 static bool dccp_new(struct nf_conn *ct, const struct sk_buff *skb,
423                      unsigned int dataoff, unsigned int *timeouts)
424 {
425         struct net *net = nf_ct_net(ct);
426         struct dccp_net *dn;
427         struct dccp_hdr _dh, *dh;
428         const char *msg;
429         u_int8_t state;
430 
431         dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &_dh);
432         BUG_ON(dh == NULL);
433 
434         state = dccp_state_table[CT_DCCP_ROLE_CLIENT][dh->dccph_type][CT_DCCP_NONE];
435         switch (state) {
436         default:
437                 dn = dccp_pernet(net);
438                 if (dn->dccp_loose == 0) {
439                         msg = "nf_ct_dccp: not picking up existing connection ";
440                         goto out_invalid;
441                 }
442         case CT_DCCP_REQUEST:
443                 break;
444         case CT_DCCP_INVALID:
445                 msg = "nf_ct_dccp: invalid state transition ";
446                 goto out_invalid;
447         }
448 
449         ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_CLIENT;
450         ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_SERVER;
451         ct->proto.dccp.state = CT_DCCP_NONE;
452         ct->proto.dccp.last_pkt = DCCP_PKT_REQUEST;
453         ct->proto.dccp.last_dir = IP_CT_DIR_ORIGINAL;
454         ct->proto.dccp.handshake_seq = 0;
455         return true;
456 
457 out_invalid:
458         if (LOG_INVALID(net, IPPROTO_DCCP))
459                 nf_log_packet(net, nf_ct_l3num(ct), 0, skb, NULL, NULL,
460                               NULL, "%s", msg);
461         return false;
462 }
463 
464 static u64 dccp_ack_seq(const struct dccp_hdr *dh)
465 {
466         const struct dccp_hdr_ack_bits *dhack;
467 
468         dhack = (void *)dh + __dccp_basic_hdr_len(dh);
469         return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) +
470                      ntohl(dhack->dccph_ack_nr_low);
471 }
472 
473 static unsigned int *dccp_get_timeouts(struct net *net)
474 {
475         return dccp_pernet(net)->dccp_timeout;
476 }
477 
478 static int dccp_packet(struct nf_conn *ct, const struct sk_buff *skb,
479                        unsigned int dataoff, enum ip_conntrack_info ctinfo,
480                        u_int8_t pf, unsigned int hooknum,
481                        unsigned int *timeouts)
482 {
483         struct net *net = nf_ct_net(ct);
484         enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
485         struct dccp_hdr _dh, *dh;
486         u_int8_t type, old_state, new_state;
487         enum ct_dccp_roles role;
488 
489         dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &_dh);
490         BUG_ON(dh == NULL);
491         type = dh->dccph_type;
492 
493         if (type == DCCP_PKT_RESET &&
494             !test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
495                 /* Tear down connection immediately if only reply is a RESET */
496                 nf_ct_kill_acct(ct, ctinfo, skb);
497                 return NF_ACCEPT;
498         }
499 
500         spin_lock_bh(&ct->lock);
501 
502         role = ct->proto.dccp.role[dir];
503         old_state = ct->proto.dccp.state;
504         new_state = dccp_state_table[role][type][old_state];
505 
506         switch (new_state) {
507         case CT_DCCP_REQUEST:
508                 if (old_state == CT_DCCP_TIMEWAIT &&
509                     role == CT_DCCP_ROLE_SERVER) {
510                         /* Reincarnation in the reverse direction: reopen and
511                          * reverse client/server roles. */
512                         ct->proto.dccp.role[dir] = CT_DCCP_ROLE_CLIENT;
513                         ct->proto.dccp.role[!dir] = CT_DCCP_ROLE_SERVER;
514                 }
515                 break;
516         case CT_DCCP_RESPOND:
517                 if (old_state == CT_DCCP_REQUEST)
518                         ct->proto.dccp.handshake_seq = dccp_hdr_seq(dh);
519                 break;
520         case CT_DCCP_PARTOPEN:
521                 if (old_state == CT_DCCP_RESPOND &&
522                     type == DCCP_PKT_ACK &&
523                     dccp_ack_seq(dh) == ct->proto.dccp.handshake_seq)
524                         set_bit(IPS_ASSURED_BIT, &ct->status);
525                 break;
526         case CT_DCCP_IGNORE:
527                 /*
528                  * Connection tracking might be out of sync, so we ignore
529                  * packets that might establish a new connection and resync
530                  * if the server responds with a valid Response.
531                  */
532                 if (ct->proto.dccp.last_dir == !dir &&
533                     ct->proto.dccp.last_pkt == DCCP_PKT_REQUEST &&
534                     type == DCCP_PKT_RESPONSE) {
535                         ct->proto.dccp.role[!dir] = CT_DCCP_ROLE_CLIENT;
536                         ct->proto.dccp.role[dir] = CT_DCCP_ROLE_SERVER;
537                         ct->proto.dccp.handshake_seq = dccp_hdr_seq(dh);
538                         new_state = CT_DCCP_RESPOND;
539                         break;
540                 }
541                 ct->proto.dccp.last_dir = dir;
542                 ct->proto.dccp.last_pkt = type;
543 
544                 spin_unlock_bh(&ct->lock);
545                 if (LOG_INVALID(net, IPPROTO_DCCP))
546                         nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
547                                       "nf_ct_dccp: invalid packet ignored ");
548                 return NF_ACCEPT;
549         case CT_DCCP_INVALID:
550                 spin_unlock_bh(&ct->lock);
551                 if (LOG_INVALID(net, IPPROTO_DCCP))
552                         nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
553                                       "nf_ct_dccp: invalid state transition ");
554                 return -NF_ACCEPT;
555         }
556 
557         ct->proto.dccp.last_dir = dir;
558         ct->proto.dccp.last_pkt = type;
559         ct->proto.dccp.state = new_state;
560         spin_unlock_bh(&ct->lock);
561 
562         if (new_state != old_state)
563                 nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
564 
565         nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[new_state]);
566 
567         return NF_ACCEPT;
568 }
569 
570 static int dccp_error(struct net *net, struct nf_conn *tmpl,
571                       struct sk_buff *skb, unsigned int dataoff,
572                       enum ip_conntrack_info *ctinfo,
573                       u_int8_t pf, unsigned int hooknum)
574 {
575         struct dccp_hdr _dh, *dh;
576         unsigned int dccp_len = skb->len - dataoff;
577         unsigned int cscov;
578         const char *msg;
579 
580         dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &_dh);
581         if (dh == NULL) {
582                 msg = "nf_ct_dccp: short packet ";
583                 goto out_invalid;
584         }
585 
586         if (dh->dccph_doff * 4 < sizeof(struct dccp_hdr) ||
587             dh->dccph_doff * 4 > dccp_len) {
588                 msg = "nf_ct_dccp: truncated/malformed packet ";
589                 goto out_invalid;
590         }
591 
592         cscov = dccp_len;
593         if (dh->dccph_cscov) {
594                 cscov = (dh->dccph_cscov - 1) * 4;
595                 if (cscov > dccp_len) {
596                         msg = "nf_ct_dccp: bad checksum coverage ";
597                         goto out_invalid;
598                 }
599         }
600 
601         if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
602             nf_checksum_partial(skb, hooknum, dataoff, cscov, IPPROTO_DCCP,
603                                 pf)) {
604                 msg = "nf_ct_dccp: bad checksum ";
605                 goto out_invalid;
606         }
607 
608         if (dh->dccph_type >= DCCP_PKT_INVALID) {
609                 msg = "nf_ct_dccp: reserved packet type ";
610                 goto out_invalid;
611         }
612 
613         return NF_ACCEPT;
614 
615 out_invalid:
616         if (LOG_INVALID(net, IPPROTO_DCCP))
617                 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL, "%s", msg);
618         return -NF_ACCEPT;
619 }
620 
621 static void dccp_print_tuple(struct seq_file *s,
622                              const struct nf_conntrack_tuple *tuple)
623 {
624         seq_printf(s, "sport=%hu dport=%hu ",
625                    ntohs(tuple->src.u.dccp.port),
626                    ntohs(tuple->dst.u.dccp.port));
627 }
628 
629 static void dccp_print_conntrack(struct seq_file *s, struct nf_conn *ct)
630 {
631         seq_printf(s, "%s ", dccp_state_names[ct->proto.dccp.state]);
632 }
633 
634 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
635 static int dccp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
636                           struct nf_conn *ct)
637 {
638         struct nlattr *nest_parms;
639 
640         spin_lock_bh(&ct->lock);
641         nest_parms = nla_nest_start(skb, CTA_PROTOINFO_DCCP | NLA_F_NESTED);
642         if (!nest_parms)
643                 goto nla_put_failure;
644         if (nla_put_u8(skb, CTA_PROTOINFO_DCCP_STATE, ct->proto.dccp.state) ||
645             nla_put_u8(skb, CTA_PROTOINFO_DCCP_ROLE,
646                        ct->proto.dccp.role[IP_CT_DIR_ORIGINAL]) ||
647             nla_put_be64(skb, CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ,
648                          cpu_to_be64(ct->proto.dccp.handshake_seq)))
649                 goto nla_put_failure;
650         nla_nest_end(skb, nest_parms);
651         spin_unlock_bh(&ct->lock);
652         return 0;
653 
654 nla_put_failure:
655         spin_unlock_bh(&ct->lock);
656         return -1;
657 }
658 
659 static const struct nla_policy dccp_nla_policy[CTA_PROTOINFO_DCCP_MAX + 1] = {
660         [CTA_PROTOINFO_DCCP_STATE]      = { .type = NLA_U8 },
661         [CTA_PROTOINFO_DCCP_ROLE]       = { .type = NLA_U8 },
662         [CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ] = { .type = NLA_U64 },
663 };
664 
665 static int nlattr_to_dccp(struct nlattr *cda[], struct nf_conn *ct)
666 {
667         struct nlattr *attr = cda[CTA_PROTOINFO_DCCP];
668         struct nlattr *tb[CTA_PROTOINFO_DCCP_MAX + 1];
669         int err;
670 
671         if (!attr)
672                 return 0;
673 
674         err = nla_parse_nested(tb, CTA_PROTOINFO_DCCP_MAX, attr,
675                                dccp_nla_policy);
676         if (err < 0)
677                 return err;
678 
679         if (!tb[CTA_PROTOINFO_DCCP_STATE] ||
680             !tb[CTA_PROTOINFO_DCCP_ROLE] ||
681             nla_get_u8(tb[CTA_PROTOINFO_DCCP_ROLE]) > CT_DCCP_ROLE_MAX ||
682             nla_get_u8(tb[CTA_PROTOINFO_DCCP_STATE]) >= CT_DCCP_IGNORE) {
683                 return -EINVAL;
684         }
685 
686         spin_lock_bh(&ct->lock);
687         ct->proto.dccp.state = nla_get_u8(tb[CTA_PROTOINFO_DCCP_STATE]);
688         if (nla_get_u8(tb[CTA_PROTOINFO_DCCP_ROLE]) == CT_DCCP_ROLE_CLIENT) {
689                 ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_CLIENT;
690                 ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_SERVER;
691         } else {
692                 ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_SERVER;
693                 ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_CLIENT;
694         }
695         if (tb[CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ]) {
696                 ct->proto.dccp.handshake_seq =
697                 be64_to_cpu(nla_get_be64(tb[CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ]));
698         }
699         spin_unlock_bh(&ct->lock);
700         return 0;
701 }
702 
703 static int dccp_nlattr_size(void)
704 {
705         return nla_total_size(0)        /* CTA_PROTOINFO_DCCP */
706                 + nla_policy_len(dccp_nla_policy, CTA_PROTOINFO_DCCP_MAX + 1);
707 }
708 
709 #endif
710 
711 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
712 
713 #include <linux/netfilter/nfnetlink.h>
714 #include <linux/netfilter/nfnetlink_cttimeout.h>
715 
716 static int dccp_timeout_nlattr_to_obj(struct nlattr *tb[],
717                                       struct net *net, void *data)
718 {
719         struct dccp_net *dn = dccp_pernet(net);
720         unsigned int *timeouts = data;
721         int i;
722 
723         /* set default DCCP timeouts. */
724         for (i=0; i<CT_DCCP_MAX; i++)
725                 timeouts[i] = dn->dccp_timeout[i];
726 
727         /* there's a 1:1 mapping between attributes and protocol states. */
728         for (i=CTA_TIMEOUT_DCCP_UNSPEC+1; i<CTA_TIMEOUT_DCCP_MAX+1; i++) {
729                 if (tb[i]) {
730                         timeouts[i] = ntohl(nla_get_be32(tb[i])) * HZ;
731                 }
732         }
733         return 0;
734 }
735 
736 static int
737 dccp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
738 {
739         const unsigned int *timeouts = data;
740         int i;
741 
742         for (i=CTA_TIMEOUT_DCCP_UNSPEC+1; i<CTA_TIMEOUT_DCCP_MAX+1; i++) {
743                 if (nla_put_be32(skb, i, htonl(timeouts[i] / HZ)))
744                         goto nla_put_failure;
745         }
746         return 0;
747 
748 nla_put_failure:
749         return -ENOSPC;
750 }
751 
752 static const struct nla_policy
753 dccp_timeout_nla_policy[CTA_TIMEOUT_DCCP_MAX+1] = {
754         [CTA_TIMEOUT_DCCP_REQUEST]      = { .type = NLA_U32 },
755         [CTA_TIMEOUT_DCCP_RESPOND]      = { .type = NLA_U32 },
756         [CTA_TIMEOUT_DCCP_PARTOPEN]     = { .type = NLA_U32 },
757         [CTA_TIMEOUT_DCCP_OPEN]         = { .type = NLA_U32 },
758         [CTA_TIMEOUT_DCCP_CLOSEREQ]     = { .type = NLA_U32 },
759         [CTA_TIMEOUT_DCCP_CLOSING]      = { .type = NLA_U32 },
760         [CTA_TIMEOUT_DCCP_TIMEWAIT]     = { .type = NLA_U32 },
761 };
762 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
763 
764 #ifdef CONFIG_SYSCTL
765 /* template, data assigned later */
766 static struct ctl_table dccp_sysctl_table[] = {
767         {
768                 .procname       = "nf_conntrack_dccp_timeout_request",
769                 .maxlen         = sizeof(unsigned int),
770                 .mode           = 0644,
771                 .proc_handler   = proc_dointvec_jiffies,
772         },
773         {
774                 .procname       = "nf_conntrack_dccp_timeout_respond",
775                 .maxlen         = sizeof(unsigned int),
776                 .mode           = 0644,
777                 .proc_handler   = proc_dointvec_jiffies,
778         },
779         {
780                 .procname       = "nf_conntrack_dccp_timeout_partopen",
781                 .maxlen         = sizeof(unsigned int),
782                 .mode           = 0644,
783                 .proc_handler   = proc_dointvec_jiffies,
784         },
785         {
786                 .procname       = "nf_conntrack_dccp_timeout_open",
787                 .maxlen         = sizeof(unsigned int),
788                 .mode           = 0644,
789                 .proc_handler   = proc_dointvec_jiffies,
790         },
791         {
792                 .procname       = "nf_conntrack_dccp_timeout_closereq",
793                 .maxlen         = sizeof(unsigned int),
794                 .mode           = 0644,
795                 .proc_handler   = proc_dointvec_jiffies,
796         },
797         {
798                 .procname       = "nf_conntrack_dccp_timeout_closing",
799                 .maxlen         = sizeof(unsigned int),
800                 .mode           = 0644,
801                 .proc_handler   = proc_dointvec_jiffies,
802         },
803         {
804                 .procname       = "nf_conntrack_dccp_timeout_timewait",
805                 .maxlen         = sizeof(unsigned int),
806                 .mode           = 0644,
807                 .proc_handler   = proc_dointvec_jiffies,
808         },
809         {
810                 .procname       = "nf_conntrack_dccp_loose",
811                 .maxlen         = sizeof(int),
812                 .mode           = 0644,
813                 .proc_handler   = proc_dointvec,
814         },
815         { }
816 };
817 #endif /* CONFIG_SYSCTL */
818 
819 static int dccp_kmemdup_sysctl_table(struct net *net, struct nf_proto_net *pn,
820                                      struct dccp_net *dn)
821 {
822 #ifdef CONFIG_SYSCTL
823         if (pn->ctl_table)
824                 return 0;
825 
826         pn->ctl_table = kmemdup(dccp_sysctl_table,
827                                 sizeof(dccp_sysctl_table),
828                                 GFP_KERNEL);
829         if (!pn->ctl_table)
830                 return -ENOMEM;
831 
832         pn->ctl_table[0].data = &dn->dccp_timeout[CT_DCCP_REQUEST];
833         pn->ctl_table[1].data = &dn->dccp_timeout[CT_DCCP_RESPOND];
834         pn->ctl_table[2].data = &dn->dccp_timeout[CT_DCCP_PARTOPEN];
835         pn->ctl_table[3].data = &dn->dccp_timeout[CT_DCCP_OPEN];
836         pn->ctl_table[4].data = &dn->dccp_timeout[CT_DCCP_CLOSEREQ];
837         pn->ctl_table[5].data = &dn->dccp_timeout[CT_DCCP_CLOSING];
838         pn->ctl_table[6].data = &dn->dccp_timeout[CT_DCCP_TIMEWAIT];
839         pn->ctl_table[7].data = &dn->dccp_loose;
840 
841         /* Don't export sysctls to unprivileged users */
842         if (net->user_ns != &init_user_ns)
843                 pn->ctl_table[0].procname = NULL;
844 #endif
845         return 0;
846 }
847 
848 static int dccp_init_net(struct net *net, u_int16_t proto)
849 {
850         struct dccp_net *dn = dccp_pernet(net);
851         struct nf_proto_net *pn = &dn->pn;
852 
853         if (!pn->users) {
854                 /* default values */
855                 dn->dccp_loose = 1;
856                 dn->dccp_timeout[CT_DCCP_REQUEST]       = 2 * DCCP_MSL;
857                 dn->dccp_timeout[CT_DCCP_RESPOND]       = 4 * DCCP_MSL;
858                 dn->dccp_timeout[CT_DCCP_PARTOPEN]      = 4 * DCCP_MSL;
859                 dn->dccp_timeout[CT_DCCP_OPEN]          = 12 * 3600 * HZ;
860                 dn->dccp_timeout[CT_DCCP_CLOSEREQ]      = 64 * HZ;
861                 dn->dccp_timeout[CT_DCCP_CLOSING]       = 64 * HZ;
862                 dn->dccp_timeout[CT_DCCP_TIMEWAIT]      = 2 * DCCP_MSL;
863         }
864 
865         return dccp_kmemdup_sysctl_table(net, pn, dn);
866 }
867 
868 static struct nf_conntrack_l4proto dccp_proto4 __read_mostly = {
869         .l3proto                = AF_INET,
870         .l4proto                = IPPROTO_DCCP,
871         .name                   = "dccp",
872         .pkt_to_tuple           = dccp_pkt_to_tuple,
873         .invert_tuple           = dccp_invert_tuple,
874         .new                    = dccp_new,
875         .packet                 = dccp_packet,
876         .get_timeouts           = dccp_get_timeouts,
877         .error                  = dccp_error,
878         .print_tuple            = dccp_print_tuple,
879         .print_conntrack        = dccp_print_conntrack,
880 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
881         .to_nlattr              = dccp_to_nlattr,
882         .nlattr_size            = dccp_nlattr_size,
883         .from_nlattr            = nlattr_to_dccp,
884         .tuple_to_nlattr        = nf_ct_port_tuple_to_nlattr,
885         .nlattr_tuple_size      = nf_ct_port_nlattr_tuple_size,
886         .nlattr_to_tuple        = nf_ct_port_nlattr_to_tuple,
887         .nla_policy             = nf_ct_port_nla_policy,
888 #endif
889 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
890         .ctnl_timeout           = {
891                 .nlattr_to_obj  = dccp_timeout_nlattr_to_obj,
892                 .obj_to_nlattr  = dccp_timeout_obj_to_nlattr,
893                 .nlattr_max     = CTA_TIMEOUT_DCCP_MAX,
894                 .obj_size       = sizeof(unsigned int) * CT_DCCP_MAX,
895                 .nla_policy     = dccp_timeout_nla_policy,
896         },
897 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
898         .net_id                 = &dccp_net_id,
899         .init_net               = dccp_init_net,
900 };
901 
902 static struct nf_conntrack_l4proto dccp_proto6 __read_mostly = {
903         .l3proto                = AF_INET6,
904         .l4proto                = IPPROTO_DCCP,
905         .name                   = "dccp",
906         .pkt_to_tuple           = dccp_pkt_to_tuple,
907         .invert_tuple           = dccp_invert_tuple,
908         .new                    = dccp_new,
909         .packet                 = dccp_packet,
910         .get_timeouts           = dccp_get_timeouts,
911         .error                  = dccp_error,
912         .print_tuple            = dccp_print_tuple,
913         .print_conntrack        = dccp_print_conntrack,
914 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
915         .to_nlattr              = dccp_to_nlattr,
916         .nlattr_size            = dccp_nlattr_size,
917         .from_nlattr            = nlattr_to_dccp,
918         .tuple_to_nlattr        = nf_ct_port_tuple_to_nlattr,
919         .nlattr_tuple_size      = nf_ct_port_nlattr_tuple_size,
920         .nlattr_to_tuple        = nf_ct_port_nlattr_to_tuple,
921         .nla_policy             = nf_ct_port_nla_policy,
922 #endif
923 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
924         .ctnl_timeout           = {
925                 .nlattr_to_obj  = dccp_timeout_nlattr_to_obj,
926                 .obj_to_nlattr  = dccp_timeout_obj_to_nlattr,
927                 .nlattr_max     = CTA_TIMEOUT_DCCP_MAX,
928                 .obj_size       = sizeof(unsigned int) * CT_DCCP_MAX,
929                 .nla_policy     = dccp_timeout_nla_policy,
930         },
931 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
932         .net_id                 = &dccp_net_id,
933         .init_net               = dccp_init_net,
934 };
935 
936 static __net_init int dccp_net_init(struct net *net)
937 {
938         int ret = 0;
939         ret = nf_ct_l4proto_pernet_register(net, &dccp_proto4);
940         if (ret < 0) {
941                 pr_err("nf_conntrack_dccp4: pernet registration failed.\n");
942                 goto out;
943         }
944         ret = nf_ct_l4proto_pernet_register(net, &dccp_proto6);
945         if (ret < 0) {
946                 pr_err("nf_conntrack_dccp6: pernet registration failed.\n");
947                 goto cleanup_dccp4;
948         }
949         return 0;
950 cleanup_dccp4:
951         nf_ct_l4proto_pernet_unregister(net, &dccp_proto4);
952 out:
953         return ret;
954 }
955 
956 static __net_exit void dccp_net_exit(struct net *net)
957 {
958         nf_ct_l4proto_pernet_unregister(net, &dccp_proto6);
959         nf_ct_l4proto_pernet_unregister(net, &dccp_proto4);
960 }
961 
962 static struct pernet_operations dccp_net_ops = {
963         .init = dccp_net_init,
964         .exit = dccp_net_exit,
965         .id   = &dccp_net_id,
966         .size = sizeof(struct dccp_net),
967 };
968 
969 static int __init nf_conntrack_proto_dccp_init(void)
970 {
971         int ret;
972 
973         ret = register_pernet_subsys(&dccp_net_ops);
974         if (ret < 0)
975                 goto out_pernet;
976 
977         ret = nf_ct_l4proto_register(&dccp_proto4);
978         if (ret < 0)
979                 goto out_dccp4;
980 
981         ret = nf_ct_l4proto_register(&dccp_proto6);
982         if (ret < 0)
983                 goto out_dccp6;
984 
985         return 0;
986 out_dccp6:
987         nf_ct_l4proto_unregister(&dccp_proto4);
988 out_dccp4:
989         unregister_pernet_subsys(&dccp_net_ops);
990 out_pernet:
991         return ret;
992 }
993 
994 static void __exit nf_conntrack_proto_dccp_fini(void)
995 {
996         nf_ct_l4proto_unregister(&dccp_proto6);
997         nf_ct_l4proto_unregister(&dccp_proto4);
998         unregister_pernet_subsys(&dccp_net_ops);
999 }
1000 
1001 module_init(nf_conntrack_proto_dccp_init);
1002 module_exit(nf_conntrack_proto_dccp_fini);
1003 
1004 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
1005 MODULE_DESCRIPTION("DCCP connection tracking protocol helper");
1006 MODULE_LICENSE("GPL");
1007 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp