1 /* When dealing with SLIP (to a pty, or ipif) we have separate rx, tx
2 and client buffers. When receiving we may read() any amount, not
3 just whole packets. When transmitting we need to bytestuff anyway,
4 and may be part-way through receiving. */
7 * This file is part of secnet.
8 * See README for full list of copyright holders.
10 * secnet is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version d of the License, or
13 * (at your option) any later version.
15 * secnet is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * version 3 along with secnet; if not, see
22 * https://www.gnu.org/licenses/gpl.html.
29 #include "unaligned.h"
38 #define SLIP_ESCEND 220
39 #define SLIP_ESCESC 221
43 struct buffer_if
*buff
; /* We unstuff received packets into here
44 and send them to the netlink code. */
46 bool_t ignoring_packet
; /* If this packet was corrupt or overlong,
47 we ignore everything up to the next END */
48 netlink_deliver_fn
*netlink_to_tunnel
;
51 /* Generic SLIP mangling code */
53 static void slip_write(int fd
, const uint8_t *p
, size_t l
)
56 ssize_t written
=write(fd
,p
,l
);
60 } else if (iswouldblock(errno
)) {
61 lg_perror(0,"slip",0,M_ERR
,errno
,"write() (packet(s) lost)");
64 fatal_perror("slip_stuff: write()");
68 assert((size_t)written
<=l
);
74 static void slip_stuff(struct slip
*st
, struct buffer_if
*buf
, int fd
)
76 uint8_t txbuf
[DEFAULT_BUFSIZE
];
82 /* There's probably a much more efficient way of implementing this */
84 for (i
=buf
->start
; i
<(buf
->start
+buf
->size
); i
++) {
88 txbuf
[j
++]=SLIP_ESCEND
;
92 txbuf
[j
++]=SLIP_ESCESC
;
98 if ((j
+2)>DEFAULT_BUFSIZE
) {
99 slip_write(fd
,txbuf
,j
);
104 slip_write(fd
,txbuf
,j
);
108 static void slip_unstuff(struct slip
*st
, uint8_t *buf
, uint32_t l
)
112 BUF_ASSERT_USED(st
->buff
);
113 for (i
=0; i
<l
; i
++) {
115 enum { OUTPUT_END
= 256, OUTPUT_NOTHING
= 257 };
118 buffer_init(st
->buff
,calculate_max_start_pad());
120 if (st
->pending_esc
) {
121 st
->pending_esc
=False
;
130 if (!st
->ignoring_packet
) {
131 Message(M_WARNING
, "userv_afterpoll: bad SLIP escape"
132 " character, dropping packet\n");
134 st
->ignoring_packet
=True
;
135 outputchr
=OUTPUT_NOTHING
;
141 outputchr
=OUTPUT_END
;
144 st
->pending_esc
=True
;
145 outputchr
=OUTPUT_NOTHING
;
153 if (st
->ignoring_packet
) {
154 if (outputchr
== OUTPUT_END
) {
155 st
->ignoring_packet
=False
;
159 if (outputchr
== OUTPUT_END
) {
160 if (st
->buff
->size
>0) {
161 st
->netlink_to_tunnel(&st
->nl
,st
->buff
);
162 BUF_ALLOC(st
->buff
,"userv_afterpoll");
165 } else if (outputchr
!= OUTPUT_NOTHING
) {
166 if (buf_remaining_space(st
->buff
)) {
167 buf_append_uint8(st
->buff
,outputchr
);
169 Message(M_WARNING
, "userv_afterpoll: dropping overlong"
171 st
->ignoring_packet
=True
;
178 static void slip_init(struct slip
*st
, struct cloc loc
, dict_t
*dict
,
179 cstring_t name
, netlink_deliver_fn
*to_host
)
181 st
->netlink_to_tunnel
=
182 netlink_init(&st
->nl
,st
,loc
,dict
,
183 "netlink-userv-ipif",NULL
,to_host
);
184 st
->buff
=find_cl_if(dict
,"buffer",CL_BUFFER
,True
,"name",loc
);
185 BUF_ALLOC(st
->buff
,"slip_init");
186 st
->pending_esc
=False
;
187 st
->ignoring_packet
=False
;
190 /* Connection to the kernel through userv-ipif */
194 int txfd
; /* We transmit to userv */
195 int rxfd
; /* We receive from userv */
196 cstring_t userv_path
;
197 cstring_t service_user
;
198 cstring_t service_name
;
200 bool_t expecting_userv_exit
;
203 static int userv_beforepoll(void *sst
, struct pollfd
*fds
, int *nfds_io
,
206 struct userv
*st
=sst
;
209 BEFOREPOLL_WANT_FDS(2);
211 fds
[0].events
=0; /* Might want to pick up POLLOUT sometime */
213 fds
[1].events
=POLLIN
;
215 BEFOREPOLL_WANT_FDS(0);
220 static void userv_afterpoll(void *sst
, struct pollfd
*fds
, int nfds
)
222 struct userv
*st
=sst
;
223 uint8_t rxbuf
[DEFAULT_BUFSIZE
];
228 if (fds
[1].revents
&POLLERR
) {
229 Message(M_ERR
,"%s: userv_afterpoll: POLLERR!\n",st
->slip
.nl
.name
);
231 if (fds
[1].revents
&POLLIN
) {
232 l
=read(st
->rxfd
,rxbuf
,DEFAULT_BUFSIZE
);
234 if (errno
!=EINTR
&& !iswouldblock(errno
))
235 fatal_perror("%s: userv_afterpoll: read(rxfd)",
238 fatal("%s: userv_afterpoll: read(rxfd)=0; userv gone away?",
240 } else slip_unstuff(&st
->slip
,rxbuf
,l
);
244 /* Send buf to the kernel. Free buf before returning. */
245 static void userv_deliver_to_kernel(void *sst
, struct buffer_if
*buf
)
247 struct userv
*st
=sst
;
249 if (buf
->size
> st
->slip
.nl
.mtu
) {
250 Message(M_ERR
,"%s: packet of size %"PRIu32
" exceeds mtu %"PRIu32
":"
251 " cannot be injected into kernel, dropped\n",
252 st
->slip
.nl
.name
, buf
->size
, st
->slip
.nl
.mtu
);
257 slip_stuff(&st
->slip
,buf
,st
->txfd
);
260 static void userv_userv_callback(void *sst
, pid_t pid
, int status
)
262 struct userv
*st
=sst
;
265 Message(M_WARNING
,"userv_callback called unexpectedly with pid %d "
266 "(expected %d)\n",pid
,st
->pid
);
269 if (!(st
->expecting_userv_exit
&&
271 (WIFSIGNALED(status
) && WTERMSIG(status
)==SIGTERM
)))) {
272 lg_exitstatus(0,st
->slip
.nl
.name
,0,
273 st
->expecting_userv_exit ? M_WARNING
: M_FATAL
,
279 struct userv_entry_rec
{
284 /* XXX perhaps we should collect and log stderr? */
287 static void userv_entry(void *sst
)
289 struct userv_entry_rec
*st
=sst
;
295 execvp(st
->path
,(char *const*)st
->argv
);
296 perror("userv-entry: execvp()");
300 static void userv_invoke_userv(struct userv
*st
)
302 struct userv_entry_rec er
[1];
307 struct netlink_client
*r
;
308 struct ipset
*allnets
;
309 struct subnet_list
*snets
;
314 fatal("userv_invoke_userv: already running");
317 /* This is where we actually invoke userv - all the networks we'll
318 be using should already have been registered. */
321 snprintf(addrs
,sizeof(addrs
),"%s,%s,%d,slip",
322 ipaddr_to_string(st
->slip
.nl
.local_address
),
323 ipaddr_to_string(st
->slip
.nl
.secnet_address
),st
->slip
.nl
.mtu
);
326 for (r
=st
->slip
.nl
.clients
; r
; r
=r
->next
) {
327 if (r
->link_quality
> LINK_QUALITY_UNUSED
) {
330 nan
=ipset_union(allnets
,r
->networks
);
335 snets
=ipset_to_subnet_list(allnets
);
337 nets
=safe_malloc(20*snets
->entries
,"userv_invoke_userv:nets");
339 for (i
=0; i
<snets
->entries
; i
++) {
340 s
=subnet_to_string(snets
->list
[i
]);
344 nets
[strlen(nets
)-1]=0;
345 subnet_list_free(snets
);
347 Message(M_INFO
,"%s: about to invoke: %s %s %s %s %s\n",st
->slip
.nl
.name
,
348 st
->userv_path
,st
->service_user
,st
->service_name
,addrs
,nets
);
350 st
->slip
.pending_esc
=False
;
353 pipe_cloexec(c_stdin
);
354 pipe_cloexec(c_stdout
);
356 st
->rxfd
=c_stdout
[0];
360 /* The arguments are:
364 local-addr,secnet-addr,mtu,protocol
366 const char *er_argv
[6];
368 er
->argv
[0]=st
->userv_path
;
369 er
->argv
[1]=st
->service_user
;
370 er
->argv
[2]=st
->service_name
;
374 er
->path
=st
->userv_path
;
376 st
->pid
=makesubproc(userv_entry
, userv_userv_callback
,
377 er
, st
, st
->slip
.nl
.name
);
381 Message(M_INFO
,"%s: userv-ipif pid is %d\n",st
->slip
.nl
.name
,st
->pid
);
382 /* Read a single character from the pipe to confirm userv-ipif is
383 running. If we get a SIGCHLD at this point then we'll get EINTR. */
384 if ((nread
=read(st
->rxfd
,&confirm
,1))!=1) {
386 Message(M_WARNING
,"%s: read of confirmation byte was "
387 "interrupted\n",st
->slip
.nl
.name
);
390 fatal_perror("%s: error reading confirmation byte",
393 fatal("%s: unexpected EOF instead of confirmation byte"
394 " - userv ipif failed?", st
->slip
.nl
.name
);
398 if (confirm
!=SLIP_END
) {
399 fatal("%s: bad confirmation byte %d from userv-ipif",
400 st
->slip
.nl
.name
,confirm
);
403 setnonblock(st
->txfd
);
404 setnonblock(st
->rxfd
);
406 add_hook(PHASE_CHILDPERSIST
,childpersist_closefd_hook
,&st
->txfd
);
407 add_hook(PHASE_CHILDPERSIST
,childpersist_closefd_hook
,&st
->rxfd
);
410 static void userv_kill_userv(struct userv
*st
)
413 kill(-st
->pid
,SIGTERM
);
414 st
->expecting_userv_exit
=True
;
418 static void userv_phase_hook(void *sst
, uint32_t newphase
)
420 struct userv
*st
=sst
;
421 /* We must wait until signal processing has started before forking
423 if (newphase
==PHASE_RUN
) {
424 userv_invoke_userv(st
);
425 /* Register for poll() */
426 register_for_poll(st
, userv_beforepoll
, userv_afterpoll
,
429 if (newphase
==PHASE_SHUTDOWN
) {
430 userv_kill_userv(st
);
434 static list_t
*userv_apply(closure_t
*self
, struct cloc loc
, dict_t
*context
,
443 /* First parameter must be a dict */
444 item
=list_elem(args
,0);
445 if (!item
|| item
->type
!=t_dict
)
446 cfgfatal(loc
,"userv-ipif","parameter must be a dictionary\n");
448 dict
=item
->data
.dict
;
450 slip_init(&st
->slip
,loc
,dict
,"netlink-userv-ipif",
451 userv_deliver_to_kernel
);
453 st
->userv_path
=dict_read_string(dict
,"userv-path",False
,"userv-netlink",
455 st
->service_user
=dict_read_string(dict
,"service-user",False
,
456 "userv-netlink",loc
);
457 st
->service_name
=dict_read_string(dict
,"service-name",False
,
458 "userv-netlink",loc
);
459 if (!st
->userv_path
) st
->userv_path
="userv";
460 if (!st
->service_user
) st
->service_user
="root";
461 if (!st
->service_name
) st
->service_name
="ipif";
462 st
->rxfd
=-1; st
->txfd
=-1;
464 st
->expecting_userv_exit
=False
;
465 add_hook(PHASE_RUN
,userv_phase_hook
,st
);
466 add_hook(PHASE_SHUTDOWN
,userv_phase_hook
,st
);
468 return new_closure(&st
->slip
.nl
.cl
);
471 void slip_module(dict_t
*dict
)
473 add_closure(dict
,"userv-ipif",userv_apply
);