1 /*
2 * Copyright (c) 2018
3 * Hartmut Brandt.
4 * All rights reserved.
5 *
6 * Author: Harti Brandt <harti@freebsd.org>
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $Begemot: bsnmp/snmpd/trans_udp.c,v 1.5 2005/10/04 08:46:56 brandt_h Exp $
30 *
31 * Internet transport
32 */
33
34 #include <sys/param.h>
35 #include <sys/socket.h>
36 #include <sys/types.h>
37
38 #include <assert.h>
39 #include <errno.h>
40 #include <netdb.h>
41 #include <stdbool.h>
42 #include <stddef.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <syslog.h>
46 #include <unistd.h>
47
48 #include <stdio.h>
49
50 #include <arpa/inet.h>
51
52 #include "asn1.h"
53 #include "snmp.h"
54 #include "snmpmod.h"
55
56 #include "snmpd.h"
57
58 #define SNMPTREE_TYPES
59 #define SNMPENUM_FUNCS
60 #include "tree.h"
61 #include "oid.h"
62
63 extern const struct transport_def inet_trans;
64
65 struct inet_port;
66 struct inet_port_params;
67 struct port_sock;
68
69 typedef int create_func(struct inet_port *, struct inet_port_params *);
70 typedef void input_func(int, void *);
71 typedef int activate_func(struct inet_port *);
72 typedef void deactivate_func(struct inet_port *);
73 typedef void parse_ctrl_func(struct port_sock *, const struct msghdr *);
74 typedef void setsrc_func(struct port_sock *, struct msghdr *, char *);
75
76 static create_func ipv4_create;
77 static input_func ipv4_input;
78 static activate_func ipv4_activate;
79 static deactivate_func ipv4_deactivate;
80 static parse_ctrl_func ipv4_parse_ctrl;
81 static setsrc_func ipv4_setsrc;
82
83 static create_func ipv6_create;
84 static input_func ipv6_input;
85 static activate_func ipv6_activate;
86 static deactivate_func ipv6_deactivate;
87 static parse_ctrl_func ipv6_parse_ctrl;
88 static setsrc_func ipv6_setsrc;
89
90 static create_func ipv6z_create;
91
92 static create_func dns_create;
93 static activate_func dns_activate;
94 static deactivate_func dns_deactivate;
95
96 struct port_sock {
97 /* common input stuff; must be first */
98 struct port_input input;
99
100 /** link field */
101 TAILQ_ENTRY(port_sock) link;
102
103 /** pointer to parent */
104 struct inet_port *port;
105
106 /** bind address */
107 struct sockaddr_storage bind_addr;
108
109 /** reply destination */
110 struct sockaddr_storage ret_dest;
111
112 /** need to set source address in reply; set for INADDR_ANY */
113 bool set_ret_source;
114
115 /** address of the receive interface */
116 union {
117 /** IPv4 case */
118 struct in_addr a4;
119
120 /** IPv6 case */
121 struct in6_pktinfo a6;
122 } ret_source;
123
124 /** parse control message */
125 parse_ctrl_func *parse_ctrl;
126
127 /** set source address for a send() */
128 setsrc_func *setsrc;
129 };
130 static_assert(offsetof(struct port_sock, input) == 0,
131 "input not first in port_sock");
132
133 /**
134 * Table row for the inet ports.
135 *
136 * When actived each row can have one or several open sockets. For ipv6,
137 * ipv4 and ipv6z addresses it is always one, for dns addresses more than
138 * one socket can be open.
139 */
140 struct inet_port {
141 /** common i/o port stuff (must be first) */
142 struct tport tport;
143
144 /** transport protocol */
145 enum BegemotSnmpdTransportProto proto;
146
147 /** row status */
148 enum RowStatus row_status;
149
150 /** socket list */
151 TAILQ_HEAD(, port_sock) socks;
152
153 /** value for InetAddressType::dns */
154 char *dns_addr;
155
156 /** port number in dns case; network byte order */
157 uint16_t dns_port;
158
159 /** create a port */
160 create_func *create;
161
162 /** activate a port */
163 activate_func *activate;
164
165 /** deactivate port */
166 deactivate_func *deactivate;
167 };
168 static_assert(offsetof(struct inet_port, tport) == 0,
169 "tport not first in inet_port");
170
171 /** to be used in bind_addr field */
172 #define AF_DNS AF_VENDOR00
173
174 /** registered transport */
175 static struct transport *my_trans;
176
177 /** set operation */
178 enum {
179 SET_CREATED,
180 SET_ACTIVATED,
181 SET_DEACTIVATE,
182 SET_DESTROY,
183 };
184
185 /** length of the control data buffer */
186 static const size_t RECV_CBUF_SIZE =
187 MAX(CMSG_SPACE(SOCKCREDSIZE(CMGROUP_MAX)) +
188 CMSG_SPACE(sizeof(struct in_addr)),
189 CMSG_SPACE(SOCKCREDSIZE(CMGROUP_MAX)) +
190 CMSG_SPACE(sizeof(struct in6_pktinfo)));
191
192 /** length of the control data buffer */
193 static const size_t XMIT_CBUF_SIZE =
194 MAX(CMSG_SPACE(sizeof(struct in_addr)),
195 CMSG_SPACE(sizeof(struct in6_pktinfo)));
196
197 /**
198 * Start the transport. This registers the transport with the
199 * transport table.
200 *
201 * \return SNMP error code
202 */
203 static int
inet_start(void)204 inet_start(void)
205 {
206 return (trans_register(&inet_trans, &my_trans));
207 }
208
209 /**
210 * Stop the transport. This tries to unregister the transport which
211 * in turn fails if the list of ports is not empty.
212 *
213 * \return SNMP error code
214 */
215 static int
inet_stop(int force __unused)216 inet_stop(int force __unused)
217 {
218 if (my_trans != NULL)
219 if (trans_unregister(my_trans) != 0)
220 return (SNMP_ERR_GENERR);
221 return (SNMP_ERR_NOERROR);
222 }
223
224 /**
225 * Deactivate SNMP port.
226 *
227 * \param tp port to close
228 */
229 static void
deactivate_port(struct inet_port * p)230 deactivate_port(struct inet_port *p)
231 {
232 p->deactivate(p);
233 }
234
235 /*
236 * This function activates a port. For ports opened via the config files
237 * this is called just before entering the event loop. For ports create
238 * during runtime this is called when the RowStatus is set to Active or
239 * as second step for CreateAndGo.
240 *
241 * \param tp transport port
242 *
243 * \return SNMP error code
244 */
245 static int
inet_activate(struct tport * tp)246 inet_activate(struct tport *tp)
247 {
248 struct inet_port *port = (struct inet_port *)tp;
249
250 return (port->activate(port));
251 }
252
253 /*
254 * Close the SNMP port if it is open and destroy it.
255 *
256 * \param tp port to close
257 */
258 static void
inet_destroy_port(struct tport * tp)259 inet_destroy_port(struct tport *tp)
260 {
261 struct inet_port *port = (struct inet_port *)tp;
262
263 deactivate_port(port);
264
265 trans_remove_port(tp);
266
267 free(port->dns_addr);
268 free(port);
269 }
270
271 /**
272 * If the input struct has no buffer allocated yet, do it now. If allocation
273 * fails, read the data into a local buffer and drop it.
274 *
275 * \param pi input struct
276 *
277 * \return -1 if allocation fails, 0 otherwise
278 */
279 static int
inet_alloc_buf(struct port_input * pi)280 inet_alloc_buf(struct port_input *pi)
281 {
282 char drop_buf[2000];
283
284 if (pi->buf == NULL) {
285 if ((pi->buf = buf_alloc(0)) == NULL) {
286 (void)recvfrom(pi->fd, drop_buf, sizeof(drop_buf),
287 0, NULL, NULL);
288 return (-1);
289 }
290 pi->buflen = buf_size(0);
291 }
292 return (0);
293 }
294
295 /**
296 * Read message into input buffer. Get also the source address and any
297 * control data that is available. If the message is truncated, increment
298 * corresponding statistics.
299 *
300 * \param pi input object
301 * \param msg message object to fill
302 * \param cbuf control data buffer
303 *
304 * \return -1 when something goes wrong, 0 othersise
305 */
306 static int
inet_read_msg(struct port_input * pi,struct msghdr * msg,char * cbuf)307 inet_read_msg(struct port_input *pi, struct msghdr *msg, char *cbuf)
308 {
309 struct iovec iov[1];
310
311 iov[0].iov_base = pi->buf;
312 iov[0].iov_len = pi->buflen;
313
314 msg->msg_name = pi->peer;
315 msg->msg_namelen = pi->peerlen;
316 msg->msg_iov = iov;
317 msg->msg_iovlen = 1;
318 msg->msg_control = cbuf;
319 msg->msg_controllen = RECV_CBUF_SIZE;
320 msg->msg_flags = 0;
321
322 memset(cbuf, 0, RECV_CBUF_SIZE);
323
324 const ssize_t len = recvmsg(pi->fd, msg, 0);
325
326 if (len == -1 || len == 0)
327 /* receive error */
328 return (-1);
329
330 if (msg->msg_flags & MSG_TRUNC) {
331 /* truncated - drop */
332 snmpd_stats.silentDrops++;
333 snmpd_stats.inTooLong++;
334 return (-1);
335 }
336
337 pi->length = (size_t)len;
338
339 return (0);
340 }
341
342 /*
343 * Input available on socket.
344 *
345 * \param tp transport port
346 * \param pi input struct
347 *
348 * \return number of bytes received
349 */
350 static ssize_t
inet_recv(struct tport * tp,struct port_input * pi)351 inet_recv(struct tport *tp, struct port_input *pi)
352 {
353 struct inet_port *port = __containerof(tp, struct inet_port, tport);
354 struct port_sock *sock = __containerof(pi, struct port_sock, input);
355
356 assert(port->proto == BegemotSnmpdTransportProto_udp);
357
358 if (inet_alloc_buf(pi) == -1)
359 return (-1);
360
361 char cbuf[RECV_CBUF_SIZE];
362 struct msghdr msg;
363
364 if (inet_read_msg(pi, &msg, cbuf) == -1)
365 return (-1);
366
367 sock->parse_ctrl(sock, &msg);
368
369 return (0);
370 }
371
372 /*
373 * Send message.
374 *
375 * \param tp port
376 * \param buf data to send
377 * \param len number of bytes to send
378 * \param addr destination address
379 * \param addlen destination address length
380 *
381 * \return number of bytes sent
382 */
383 static ssize_t
inet_send2(struct tport * tp,const u_char * buf,size_t len,struct port_input * pi)384 inet_send2(struct tport *tp, const u_char *buf, size_t len,
385 struct port_input *pi)
386 {
387 struct inet_port *p = __containerof(tp, struct inet_port, tport);
388 struct port_sock *s = (pi == NULL) ? TAILQ_FIRST(&p->socks) :
389 __containerof(pi, struct port_sock, input);
390
391 struct iovec iov;
392
393 iov.iov_base = __DECONST(void*, buf);
394 iov.iov_len = len;
395
396 struct msghdr msg;
397
398 msg.msg_flags = 0;
399 msg.msg_iov = &iov;
400 msg.msg_iovlen = 1;
401 msg.msg_name = (void *)pi->peer;
402 msg.msg_namelen = pi->peerlen;
403
404 char cbuf[XMIT_CBUF_SIZE];
405 if (s->set_ret_source) {
406 s->setsrc(s, &msg, cbuf);
407 } else {
408 msg.msg_control = NULL;
409 msg.msg_controllen = 0;
410 }
411
412 return (sendmsg(s->input.fd, &msg, 0));
413 }
414
415 /** exported to daemon */
416 const struct transport_def inet_trans = {
417 "inet",
418 OIDX_begemotSnmpdTransInet,
419 inet_start,
420 inet_stop,
421 inet_destroy_port,
422 inet_activate,
423 NULL,
424 inet_recv,
425 inet_send2,
426 };
427
428 struct inet_port_params {
429 /** index oid */
430 struct asn_oid index;
431
432 /** internet address type */
433 enum InetAddressType type;
434
435 /** internet address */
436 u_char *addr;
437
438 /** length of address */
439 size_t addr_len;
440
441 /** port number */
442 uint32_t port;
443
444 /** protocol */
445 enum BegemotSnmpdTransportProto proto;
446 };
447
448 /**
449 * IPv4 creation stuff. Parse the index, fill socket address and creates
450 * a port_sock.
451 *
452 * \param port the port to create
453 * \param params parameters from the SNMP SET
454 *
455 * \return SNMP error
456 */
457 static int
ipv4_create(struct inet_port * port,struct inet_port_params * params)458 ipv4_create(struct inet_port *port, struct inet_port_params *params)
459 {
460
461 if (params->addr_len != 4)
462 return (SNMP_ERR_INCONS_VALUE);
463
464 struct port_sock *sock = calloc(1, sizeof(struct port_sock));
465 if (sock == NULL)
466 return (SNMP_ERR_GENERR);
467
468 snmpd_input_init(&sock->input);
469
470 TAILQ_INSERT_HEAD(&port->socks, sock, link);
471
472 struct sockaddr_in *sin =
473 (struct sockaddr_in *)&sock->bind_addr;
474
475 sin->sin_len = sizeof(struct sockaddr_in);
476 sin->sin_family = AF_INET;
477 sin->sin_port = htons(params->port);
478 memcpy(&sin->sin_addr, params->addr, 4); /* network byte order */
479
480 sock->port = port;
481
482 return (SNMP_ERR_NOERROR);
483 }
484
485 /*
486 * An IPv4 inet port is ready. Delegate to the generic code to read the data
487 * and react.
488 *
489 * \param fd file descriptor that is ready
490 * \param udata inet_port pointer
491 */
492 static void
ipv4_input(int fd __unused,void * udata)493 ipv4_input(int fd __unused, void *udata)
494 {
495 struct port_sock *sock = udata;
496
497 sock->input.peerlen = sizeof(struct sockaddr_in);
498 snmpd_input(&sock->input, &sock->port->tport);
499 }
500
501 /**
502 * Activate an IPv4 socket.
503 *
504 * \param sock thhe socket to activate
505 *
506 * \return error code
507 */
508 static int
ipv4_activate_sock(struct port_sock * sock)509 ipv4_activate_sock(struct port_sock *sock)
510 {
511 if ((sock->input.fd = socket(PF_INET, SOCK_DGRAM, 0)) == -1) {
512 syslog(LOG_ERR, "creating UDP4 socket: %m");
513 return (SNMP_ERR_RES_UNAVAIL);
514 }
515
516 const struct sockaddr_in *sin =
517 (const struct sockaddr_in *)&sock->bind_addr;
518
519 if (sin->sin_addr.s_addr == INADDR_ANY) {
520 /* need to know from which address to return */
521 static const int on = 1;
522
523 if (setsockopt(sock->input.fd, IPPROTO_IP, IP_RECVDSTADDR, &on,
524 sizeof(on)) == -1) {
525 syslog(LOG_ERR, "setsockopt(IP_RECVDSTADDR): %m");
526 (void)close(sock->input.fd);
527 sock->input.fd = -1;
528 return (SNMP_ERR_GENERR);
529 }
530 sock->set_ret_source = true;
531 }
532
533 if (bind(sock->input.fd, (const struct sockaddr *)sin, sizeof(*sin))) {
534 if (errno == EADDRNOTAVAIL) {
535 (void)close(sock->input.fd);
536 sock->input.fd = -1;
537 return (SNMP_ERR_INCONS_NAME);
538 }
539 syslog(LOG_ERR, "bind: %s:%u %m", inet_ntoa(sin->sin_addr),
540 ntohs(sin->sin_port));
541 (void)close(sock->input.fd);
542 sock->input.fd = -1;
543 return (SNMP_ERR_GENERR);
544 }
545
546 if ((sock->input.id = fd_select(sock->input.fd, ipv4_input,
547 sock, NULL)) == NULL) {
548 (void)close(sock->input.fd);
549 sock->input.fd = -1;
550 return (SNMP_ERR_GENERR);
551 }
552 sock->input.peer = (struct sockaddr *)&sock->ret_dest;
553
554 sock->parse_ctrl = ipv4_parse_ctrl;
555 sock->setsrc = ipv4_setsrc;
556
557 return (SNMP_ERR_NOERROR);
558 }
559
560 /**
561 * Open an IPv4 socket. Make the socket, bind it and put it on the select
562 * list. The socket struct has already been created during creation.
563 *
564 * \param p inet port
565 *
566 * \return SNMP error code
567 */
568 static int
ipv4_activate(struct inet_port * p)569 ipv4_activate(struct inet_port *p)
570 {
571 struct port_sock *sock = TAILQ_FIRST(&p->socks);
572 assert(sock);
573 assert(!TAILQ_NEXT(sock, link));
574
575 const int ret = ipv4_activate_sock(sock);
576 if (ret == SNMP_ERR_NOERROR)
577 p->row_status = RowStatus_active;
578
579 return (ret);
580 }
581
582 /**
583 * Close an IPv4 socket. Keep the sock object.
584 *
585 * \param p inet port
586 */
587 static void
ipv4_deactivate(struct inet_port * p)588 ipv4_deactivate(struct inet_port *p)
589 {
590 struct port_sock *sock = TAILQ_FIRST(&p->socks);
591 assert(sock);
592 assert(!TAILQ_NEXT(sock, link));
593
594 snmpd_input_close(&sock->input);
595
596 p->row_status = RowStatus_notInService;
597 }
598
599 /**
600 * Parse the control data received with a UDPv4 packet. This may contain
601 * credentials (for a local connection) and the address of the interface
602 * the message was received on. If there are credentials set the priv flag
603 * if the effective UID is zero.
604 *
605 * \param sock the sock object
606 * \param msg the received message
607 */
608 static void
ipv4_parse_ctrl(struct port_sock * sock,const struct msghdr * msg)609 ipv4_parse_ctrl(struct port_sock *sock, const struct msghdr *msg)
610 {
611 struct sockcred *cred = NULL;
612
613 for (struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg); cmsg != NULL;
614 cmsg = CMSG_NXTHDR(msg, cmsg)) {
615
616 if (cmsg->cmsg_level == IPPROTO_IP &&
617 cmsg->cmsg_type == IP_RECVDSTADDR) {
618 memcpy(&sock->ret_source.a4, CMSG_DATA(cmsg),
619 sizeof(struct in_addr));
620
621 } else if (cmsg->cmsg_level == SOL_SOCKET &&
622 cmsg->cmsg_type == SCM_CREDS) {
623 cred = (struct sockcred *)(void *)CMSG_DATA(cmsg);
624 }
625 }
626
627 sock->input.priv = 0;
628 if (sock->input.cred && cred)
629 /* remote end has sent credentials */
630 sock->input.priv = (cred->sc_euid == 0);
631 }
632
633 /**
634 * Set the source address option for IPv4 sockets.
635 *
636 * \param sock socket object
637 * \param msg message
638 */
639 static void
ipv4_setsrc(struct port_sock * sock,struct msghdr * msg,char * cbuf)640 ipv4_setsrc(struct port_sock *sock, struct msghdr *msg, char *cbuf)
641 {
642 struct cmsghdr *cmsg;
643
644 msg->msg_control = cbuf;
645 msg->msg_controllen = CMSG_SPACE(sizeof(struct in_addr));
646
647 /* select outgoing interface by setting source address */
648 cmsg = CMSG_FIRSTHDR(msg);
649 cmsg->cmsg_level = IPPROTO_IP;
650 cmsg->cmsg_type = IP_SENDSRCADDR;
651 cmsg->cmsg_len = CMSG_LEN(sizeof(struct in_addr));
652 memcpy(CMSG_DATA(cmsg), &sock->ret_source.a4,
653 sizeof(struct in_addr));
654 }
655
656 /**
657 * Common part of IPv6 creation. This is used by both ipv6_create() and
658 * ipv6z_create().
659 *
660 * \param port the table row
661 * \param params creation parameters
662 * \param scope_id scope_id (0 or from index)
663 *
664 * \return SNMP_ERR_NOERROR if port has been created, error code otherwise
665 */
666 static int
ipv6_create_common(struct inet_port * port,struct inet_port_params * params,u_int scope_id)667 ipv6_create_common(struct inet_port *port, struct inet_port_params *params,
668 u_int scope_id)
669 {
670 struct port_sock *sock = calloc(1, sizeof(struct port_sock));
671
672 if (sock == NULL)
673 return (SNMP_ERR_GENERR);
674
675 struct sockaddr_in6 *sin = (struct sockaddr_in6 *)&sock->bind_addr;
676
677 sin->sin6_len = sizeof(struct sockaddr_in6);
678 sin->sin6_family = AF_INET6;
679 sin->sin6_port = htons(params->port);
680 sin->sin6_flowinfo = 0;
681 sin->sin6_scope_id = scope_id;
682
683 memcpy(sin->sin6_addr.s6_addr, params->addr, 16);
684
685 if (IN6_IS_ADDR_LINKLOCAL(&sin->sin6_addr) && scope_id == 0) {
686 char buf[INET6_ADDRSTRLEN];
687 syslog(LOG_INFO, "%s: link local address used without scope "
688 "index: %s", __func__, inet_ntop(AF_INET6,
689 &sin->sin6_addr, buf, sizeof(buf)));
690 free(sock);
691 return (SNMP_ERR_NO_CREATION);
692 }
693
694 sock->port = port;
695
696 snmpd_input_init(&sock->input);
697 TAILQ_INSERT_HEAD(&port->socks, sock, link);
698
699 return (SNMP_ERR_NOERROR);
700 }
701
702 /**
703 * IPv6 creation stuff. Parse the index, fill socket address and creates
704 * a port_sock.
705 *
706 * \param port the port to create
707 * \param params parameters from the SNMP SET
708 *
709 * \return SNMP error
710 */
711 static int
ipv6_create(struct inet_port * port,struct inet_port_params * params)712 ipv6_create(struct inet_port *port, struct inet_port_params *params)
713 {
714 if (params->addr_len != 16)
715 return (SNMP_ERR_INCONS_VALUE);
716
717 const int ret = ipv6_create_common(port, params, 0);
718 if (ret != SNMP_ERR_NOERROR)
719 return (ret);
720
721 return (SNMP_ERR_NOERROR);
722 }
723
724 /*
725 * An IPv6 inet port is ready. Delegate to the generic code to read the data
726 * and react.
727 *
728 * \param fd file descriptor that is ready
729 * \param udata inet_port pointer
730 */
731 static void
ipv6_input(int fd __unused,void * udata)732 ipv6_input(int fd __unused, void *udata)
733 {
734 struct port_sock *sock = udata;
735
736 sock->input.peerlen = sizeof(struct sockaddr_in6);
737 snmpd_input(&sock->input, &sock->port->tport);
738 }
739
740 /**
741 * Activate an IPv6 socket.
742 *
743 * \param sock thhe socket to activate
744 *
745 * \return error code
746 */
747 static int
ipv6_activate_sock(struct port_sock * sock)748 ipv6_activate_sock(struct port_sock *sock)
749 {
750 if ((sock->input.fd = socket(PF_INET6, SOCK_DGRAM, 0)) == -1) {
751 syslog(LOG_ERR, "creating UDP6 socket: %m");
752 return (SNMP_ERR_RES_UNAVAIL);
753 }
754
755 const struct sockaddr_in6 *sin =
756 (const struct sockaddr_in6 *)&sock->bind_addr;
757
758 if (memcmp(&sin->sin6_addr, &in6addr_any, sizeof(in6addr_any)) == 0) {
759 /* need to know from which address to return */
760 static const int on = 1;
761
762 if (setsockopt(sock->input.fd, IPPROTO_IPV6, IPV6_RECVPKTINFO,
763 &on, sizeof(on)) == -1) {
764 syslog(LOG_ERR, "setsockopt(IP6_PKTINFO): %m");
765 (void)close(sock->input.fd);
766 sock->input.fd = -1;
767 return (SNMP_ERR_GENERR);
768 }
769 sock->set_ret_source = true;
770 }
771
772 if (bind(sock->input.fd, (const struct sockaddr *)sin, sizeof(*sin))) {
773 if (community != COMM_INITIALIZE && errno == EADDRNOTAVAIL) {
774 (void)close(sock->input.fd);
775 sock->input.fd = -1;
776 return (SNMP_ERR_INCONS_NAME);
777 }
778 char buf[INET6_ADDRSTRLEN];
779 syslog(LOG_ERR, "bind: %s:%u:%u %m", inet_ntop(AF_INET6,
780 &sin->sin6_addr, buf, sizeof(buf)), sin->sin6_scope_id,
781 ntohs(sin->sin6_port));
782 (void)close(sock->input.fd);
783 sock->input.fd = -1;
784 return (SNMP_ERR_GENERR);
785 }
786 if ((sock->input.id = fd_select(sock->input.fd, ipv6_input,
787 sock, NULL)) == NULL) {
788 (void)close(sock->input.fd);
789 sock->input.fd = -1;
790 return (SNMP_ERR_GENERR);
791 }
792 sock->input.peer = (struct sockaddr *)&sock->ret_dest;
793
794 sock->parse_ctrl = ipv6_parse_ctrl;
795 sock->setsrc = ipv6_setsrc;
796
797 return (SNMP_ERR_NOERROR);
798 }
799
800 /**
801 * Open an IPv6 socket.
802 *
803 * \param port inet port
804 *
805 * \return SNMP error code
806 */
807 static int
ipv6_activate(struct inet_port * p)808 ipv6_activate(struct inet_port *p)
809 {
810 struct port_sock *sock = TAILQ_FIRST(&p->socks);
811 assert(sock);
812
813 const int ret = ipv6_activate_sock(sock);
814
815 if (ret == SNMP_ERR_NOERROR)
816 p->row_status = RowStatus_active;
817 return (ret);
818 }
819
820 /**
821 * Close an IPv6 socket. Keep the sock object.
822 *
823 * \param p inet port
824 */
825 static void
ipv6_deactivate(struct inet_port * p)826 ipv6_deactivate(struct inet_port *p)
827 {
828 struct port_sock *sock = TAILQ_FIRST(&p->socks);
829 assert(sock);
830 assert(!TAILQ_NEXT(sock, link));
831
832 snmpd_input_close(&sock->input);
833
834 p->row_status = RowStatus_notInService;
835 }
836
837 /**
838 * IPv6 specific part of message processing. The control data may contain
839 * credentials and packet info that contains the destination address of
840 * the packet.
841 *
842 * \param sock the sock object
843 * \param msg the received message
844 */
845 static void
ipv6_parse_ctrl(struct port_sock * sock,const struct msghdr * msg)846 ipv6_parse_ctrl(struct port_sock *sock, const struct msghdr *msg)
847 {
848 struct sockcred *cred = NULL;
849
850 for (struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg); cmsg != NULL;
851 cmsg = CMSG_NXTHDR(msg, cmsg)) {
852
853 if (cmsg->cmsg_level == IPPROTO_IPV6 &&
854 cmsg->cmsg_type == IPV6_PKTINFO) {
855 const struct in6_pktinfo *info =
856 (const struct in6_pktinfo *)(const void *)
857 CMSG_DATA(cmsg);
858 sock->ret_source.a6.ipi6_addr = info->ipi6_addr;
859 sock->ret_source.a6.ipi6_ifindex =
860 !IN6_IS_ADDR_LINKLOCAL(&info->ipi6_addr) ? 0:
861 info->ipi6_ifindex;
862
863 } else if (cmsg->cmsg_level == SOL_SOCKET &&
864 cmsg->cmsg_type == SCM_CREDS) {
865 cred = (struct sockcred *)(void *)CMSG_DATA(cmsg);
866 }
867 }
868
869 sock->input.priv = 0;
870 if (sock->input.cred && cred)
871 /* remote end has sent credentials */
872 sock->input.priv = (cred->sc_euid == 0);
873 }
874
875 /**
876 * Set the source address option for IPv4 sockets.
877 *
878 * \param sock socket object
879 * \param msg message
880 */
881 static void
ipv6_setsrc(struct port_sock * sock,struct msghdr * msg,char * cbuf)882 ipv6_setsrc(struct port_sock *sock, struct msghdr *msg, char *cbuf)
883 {
884 struct cmsghdr *cmsg;
885
886 msg->msg_control = cbuf;
887 msg->msg_controllen = CMSG_SPACE(sizeof(struct in6_pktinfo));
888
889 /* select outgoing interface by setting source address */
890 cmsg = CMSG_FIRSTHDR(msg);
891 cmsg->cmsg_level = IPPROTO_IPV6;
892 cmsg->cmsg_type = IPV6_PKTINFO;
893 cmsg->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
894 memcpy(CMSG_DATA(cmsg), &sock->ret_source.a6,
895 sizeof(struct in6_pktinfo));
896 }
897
898 /**
899 * IPv6z creation stuff. Parse the index, fill socket address and creates
900 * a port_sock.
901 *
902 * \param port the port to create
903 * \param params parameters from the SNMP SET
904 *
905 * \return SNMP error
906 */
907 static int
ipv6z_create(struct inet_port * port,struct inet_port_params * params)908 ipv6z_create(struct inet_port *port, struct inet_port_params *params)
909 {
910 if (params->addr_len != 20)
911 return (SNMP_ERR_INCONS_VALUE);
912
913 u_int scope_id = 0;
914 for (u_int i = 16; i < 20; i++) {
915 scope_id <<= 8;
916 scope_id |= params->addr[i];
917 }
918
919 const int ret = ipv6_create_common(port, params, scope_id);
920 if (ret != SNMP_ERR_NOERROR)
921 return (ret);
922
923 return (SNMP_ERR_NOERROR);
924 }
925
926 /**
927 * DNS name creation stuff. Parse the index and save the string.
928 * This does not create a socket struct.
929 *
930 * \param port the port to create
931 * \param params parameters from the SNMP SET
932 *
933 * \return SNMP error
934 */
935 static int
dns_create(struct inet_port * port,struct inet_port_params * params)936 dns_create(struct inet_port *port, struct inet_port_params *params)
937 {
938 if (params->addr_len > 64)
939 return (SNMP_ERR_INCONS_VALUE);
940
941 if (strnlen(params->addr, params->addr_len) !=
942 params->addr_len)
943 return (SNMP_ERR_INCONS_VALUE);
944
945 if ((port->dns_addr = realloc(params->addr,
946 params->addr_len + 1)) == NULL)
947 return (SNMP_ERR_GENERR);
948
949 port->dns_addr[params->addr_len] = '\0';
950 params->addr = NULL;
951
952 port->dns_port = htons(params->port);
953
954 return (SNMP_ERR_NOERROR);
955 }
956
957 /**
958 * Open sockets. This loops through all the addresses returned by getaddrinfo
959 * and opens a socket for each of them.
960 *
961 * \param port inet port
962 *
963 * \return SNMP error code
964 */
965 static int
dns_activate(struct inet_port * port)966 dns_activate(struct inet_port *port)
967 {
968 struct addrinfo hints;
969 memset(&hints, 0, sizeof(hints));
970 hints.ai_family = AF_UNSPEC;
971 hints.ai_socktype = SOCK_DGRAM; // XXX udp-only
972 hints.ai_flags = AI_ADDRCONFIG | AI_PASSIVE | AI_NUMERICSERV;
973
974 char portbuf[8];
975 sprintf(portbuf, "%hu", ntohs(port->dns_port));
976
977 struct addrinfo *res0;
978 int error = getaddrinfo(port->dns_addr[0] == '\0'
979 ? NULL : port->dns_addr,
980 portbuf, &hints, &res0);
981
982 if (error) {
983 syslog(LOG_ERR, "cannot resolve address '%s': %s",
984 port->dns_addr, gai_strerror(error));
985 return (SNMP_ERR_GENERR);
986 }
987
988 for (struct addrinfo *res = res0; res != NULL; res = res->ai_next) {
989 if (res->ai_family != AF_INET && res->ai_family != AF_INET6)
990 continue;
991
992 struct port_sock *sock = calloc(1, sizeof(struct port_sock));
993 if (sock == NULL)
994 return (SNMP_ERR_GENERR);
995
996 snmpd_input_init(&sock->input);
997 sock->port = port;
998
999 int ret = SNMP_ERR_NOERROR;
1000
1001 if (res->ai_family == AF_INET) {
1002 *(struct sockaddr_in *)&sock->bind_addr =
1003 *(struct sockaddr_in *)(void *)res->ai_addr;
1004 ret = ipv4_activate_sock(sock);
1005 } else {
1006 *(struct sockaddr_in6 *)&sock->bind_addr =
1007 *(struct sockaddr_in6 *)(void *)res->ai_addr;
1008 ret = ipv6_activate_sock(sock);
1009 }
1010
1011 if (ret != SNMP_ERR_NOERROR)
1012 free(sock);
1013 else
1014 TAILQ_INSERT_HEAD(&port->socks, sock, link);
1015 }
1016
1017 if (!TAILQ_EMPTY(&port->socks))
1018 port->row_status = RowStatus_active;
1019
1020 freeaddrinfo(res0);
1021 return (SNMP_ERR_GENERR);
1022 }
1023
1024 /**
1025 * Deactive the socket. Close all open sockets and delete all sock objects.
1026 *
1027 * \param port inet port
1028 */
1029 static void
dns_deactivate(struct inet_port * port)1030 dns_deactivate(struct inet_port *port)
1031 {
1032 while (!TAILQ_EMPTY(&port->socks)) {
1033 struct port_sock *sock = TAILQ_FIRST(&port->socks);
1034 TAILQ_REMOVE(&port->socks, sock, link);
1035 snmpd_input_close(&sock->input);
1036 free(sock);
1037 }
1038 port->row_status = RowStatus_notInService;
1039 }
1040
1041 static int
inet_create(struct inet_port_params * params,struct inet_port ** pp)1042 inet_create(struct inet_port_params *params, struct inet_port **pp)
1043 {
1044 int err = SNMP_ERR_NOERROR;
1045 struct inet_port *port = NULL;
1046
1047 if (params->port > 0xffff) {
1048 err = SNMP_ERR_NO_CREATION;
1049 goto fail;
1050 }
1051
1052 if ((port = malloc(sizeof(*port))) == NULL) {
1053 err = SNMP_ERR_GENERR;
1054 goto fail;
1055 }
1056 memset(port, 0, sizeof(*port));
1057 TAILQ_INIT(&port->socks);
1058
1059 port->proto = params->proto;
1060 port->tport.index = params->index;
1061
1062 switch (params->type) {
1063
1064 case InetAddressType_ipv4:
1065 port->create = ipv4_create;
1066 port->activate = ipv4_activate;
1067 port->deactivate = ipv4_deactivate;
1068 break;
1069
1070 case InetAddressType_ipv6:
1071 port->create = ipv6_create;
1072 port->activate = ipv6_activate;
1073 port->deactivate = ipv6_deactivate;
1074 break;
1075
1076 case InetAddressType_ipv6z:
1077 port->create = ipv6z_create;
1078 port->activate = ipv6_activate;
1079 port->deactivate = ipv6_deactivate;
1080 break;
1081
1082 case InetAddressType_dns:
1083 port->create = dns_create;
1084 port->activate = dns_activate;
1085 port->deactivate = dns_deactivate;
1086 break;
1087
1088 default:
1089 err = SNMP_ERR_NO_CREATION;
1090 goto fail;
1091 }
1092
1093 if ((err = port->create(port, params)) != SNMP_ERR_NOERROR)
1094 goto fail;
1095
1096 *pp = port;
1097 trans_insert_port(my_trans, &port->tport);
1098 return (err);
1099
1100 fail:
1101 free(port->dns_addr);
1102 free(port);
1103 return (err);
1104 }
1105
1106 static int
create_and_go(struct snmp_context * ctx,struct inet_port_params * params)1107 create_and_go(struct snmp_context *ctx, struct inet_port_params *params)
1108 {
1109 int err;
1110 struct inet_port *port;
1111
1112 if ((err = inet_create(params, &port)) != SNMP_ERR_NOERROR)
1113 return (err);
1114
1115 port->row_status = RowStatus_createAndGo;
1116 ctx->scratch->ptr1 = port;
1117
1118 if (community == COMM_INITIALIZE)
1119 return (err);
1120
1121 return (inet_activate(&port->tport));
1122 }
1123
1124 static int
create_and_wait(struct snmp_context * ctx,struct inet_port_params * params)1125 create_and_wait(struct snmp_context *ctx, struct inet_port_params *params)
1126 {
1127 int err;
1128 struct inet_port *port;
1129
1130 if ((err = inet_create(params, &port)) != SNMP_ERR_NOERROR)
1131 return (err);
1132
1133 port->row_status = RowStatus_createAndWait;
1134 ctx->scratch->ptr1 = port;
1135
1136 return (err);
1137 }
1138
1139 /**
1140 * This is called to set a RowStatus value in the port table during
1141 * SET processing.
1142 *
1143 * When this is called during initialization time and the RowStatus is set
1144 * to CreateAndGo, the port is actually not activated. This is done when
1145 * the main code calls the init() for all ports later.
1146 */
1147 static int
inet_port_set(struct snmp_context * ctx,struct inet_port * port,struct inet_port_params * params,enum RowStatus nstatus)1148 inet_port_set(struct snmp_context *ctx, struct inet_port *port,
1149 struct inet_port_params *params, enum RowStatus nstatus)
1150 {
1151 switch (nstatus) {
1152
1153 case RowStatus_createAndGo:
1154 if (port != NULL)
1155 return (SNMP_ERR_INCONS_VALUE);
1156 ctx->scratch->int1 = SET_CREATED;
1157 return (create_and_go(ctx, params));
1158
1159 case RowStatus_createAndWait:
1160 if (port != NULL)
1161 return (SNMP_ERR_INCONS_VALUE);
1162 ctx->scratch->int1 = SET_CREATED;
1163 return (create_and_wait(ctx, params));
1164
1165 case RowStatus_active:
1166 if (port == NULL)
1167 return (SNMP_ERR_INCONS_VALUE);
1168
1169 switch (port->row_status) {
1170
1171 case RowStatus_notReady:
1172 /* this can not happend */
1173 abort();
1174
1175 case RowStatus_notInService:
1176 ctx->scratch->int1 = SET_ACTIVATED;
1177 return (inet_activate(&port->tport));
1178
1179 case RowStatus_active:
1180 return (SNMP_ERR_NOERROR);
1181
1182 case RowStatus_createAndGo:
1183 case RowStatus_createAndWait:
1184 case RowStatus_destroy:
1185 abort();
1186 }
1187 break;
1188
1189 case RowStatus_notInService:
1190 if (port == NULL)
1191 return (SNMP_ERR_INCONS_VALUE);
1192
1193 switch (port->row_status) {
1194
1195 case RowStatus_notReady:
1196 /* this can not happend */
1197 abort();
1198
1199 case RowStatus_notInService:
1200 return (SNMP_ERR_NOERROR);
1201
1202 case RowStatus_active:
1203 /* this is done during commit */
1204 ctx->scratch->int1 = SET_DEACTIVATE;
1205 return (SNMP_ERR_NOERROR);
1206
1207 case RowStatus_createAndGo:
1208 case RowStatus_createAndWait:
1209 case RowStatus_destroy:
1210 abort();
1211 }
1212 break;
1213
1214 case RowStatus_destroy:
1215 /* this is done during commit */
1216 ctx->scratch->int1 = SET_DESTROY;
1217 return (SNMP_ERR_NOERROR);
1218
1219 case RowStatus_notReady:
1220 return (SNMP_ERR_WRONG_VALUE);
1221 }
1222 abort();
1223 }
1224
1225 /*
1226 * Port table
1227 */
1228 int
op_snmp_trans_inet(struct snmp_context * ctx,struct snmp_value * value,u_int sub,u_int iidx __unused,enum snmp_op op)1229 op_snmp_trans_inet(struct snmp_context *ctx, struct snmp_value *value,
1230 u_int sub, u_int iidx __unused, enum snmp_op op)
1231 {
1232 asn_subid_t which = value->var.subs[sub - 1];
1233 struct inet_port *port;
1234 struct inet_port_params params;
1235 int ret;
1236
1237 switch (op) {
1238
1239 case SNMP_OP_GETNEXT:
1240 if ((port = (struct inet_port *)trans_next_port(my_trans,
1241 &value->var, sub)) == NULL)
1242 return (SNMP_ERR_NOSUCHNAME);
1243 index_append(&value->var, sub, &port->tport.index);
1244 goto fetch;
1245
1246 case SNMP_OP_GET:
1247 if ((port = (struct inet_port *)trans_find_port(my_trans,
1248 &value->var, sub)) == NULL)
1249 return (SNMP_ERR_NOSUCHNAME);
1250 goto fetch;
1251
1252 case SNMP_OP_SET:
1253 port = (struct inet_port *)trans_find_port(my_trans,
1254 &value->var, sub);
1255
1256 if (which != LEAF_begemotSnmpdTransInetStatus)
1257 abort();
1258 if (!isok_RowStatus(value->v.integer))
1259 return (SNMP_ERR_WRONG_VALUE);
1260
1261 if (index_decode(&value->var, sub, iidx, ¶ms.type,
1262 ¶ms.addr, ¶ms.addr_len, ¶ms.port,
1263 ¶ms.proto))
1264 return (SNMP_ERR_NO_CREATION);
1265
1266 asn_slice_oid(¶ms.index, &value->var, sub, value->var.len);
1267
1268 ret = inet_port_set(ctx, port, ¶ms,
1269 (enum RowStatus)value->v.integer);
1270
1271 free(params.addr);
1272 return (ret);
1273
1274 case SNMP_OP_ROLLBACK:
1275 if ((port = (struct inet_port *)trans_find_port(my_trans,
1276 &value->var, sub)) == NULL)
1277 /* cannot happen */
1278 abort();
1279
1280 switch (ctx->scratch->int1) {
1281
1282 case SET_CREATED:
1283 /* newly created */
1284 assert(port != NULL);
1285 inet_destroy_port(&port->tport);
1286 return (SNMP_ERR_NOERROR);
1287
1288 case SET_DESTROY:
1289 /* do it now */
1290 assert(port != NULL);
1291 return (SNMP_ERR_NOERROR);
1292
1293 case SET_ACTIVATED:
1294 deactivate_port(port);
1295 return (SNMP_ERR_NOERROR);
1296
1297 case SET_DEACTIVATE:
1298 return (SNMP_ERR_NOERROR);
1299 }
1300 abort();
1301
1302 case SNMP_OP_COMMIT:
1303 if ((port = (struct inet_port *)trans_find_port(my_trans,
1304 &value->var, sub)) == NULL)
1305 /* cannot happen */
1306 abort();
1307
1308 switch (ctx->scratch->int1) {
1309
1310 case SET_CREATED:
1311 /* newly created */
1312 assert(port != NULL);
1313 return (SNMP_ERR_NOERROR);
1314
1315 case SET_DESTROY:
1316 /* do it now */
1317 assert(port != NULL);
1318 inet_destroy_port(&port->tport);
1319 return (SNMP_ERR_NOERROR);
1320
1321 case SET_ACTIVATED:
1322 return (SNMP_ERR_NOERROR);
1323
1324 case SET_DEACTIVATE:
1325 deactivate_port(port);
1326 return (SNMP_ERR_NOERROR);
1327 }
1328 abort();
1329 }
1330 abort();
1331
1332 fetch:
1333 switch (which) {
1334
1335 case LEAF_begemotSnmpdTransInetStatus:
1336 value->v.integer = port->row_status;
1337 break;
1338
1339 default:
1340 abort();
1341 }
1342
1343 return (SNMP_ERR_NOERROR);
1344 }
1345