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. */
10 #include "unaligned.h"
19 #define SLIP_ESCEND 220
20 #define SLIP_ESCESC 221
24 struct buffer_if
*buff
; /* We unstuff received packets into here
25 and send them to the netlink code. */
27 bool_t ignoring_packet
; /* If this packet was corrupt or overlong,
28 we ignore everything up to the next END */
29 netlink_deliver_fn
*netlink_to_tunnel
;
30 uint32_t local_address
;
33 /* Generic SLIP mangling code */
35 static void slip_stuff(struct slip
*st
, struct buffer_if
*buf
, int fd
)
37 uint8_t txbuf
[DEFAULT_BUFSIZE
];
43 /* There's probably a much more efficient way of implementing this */
45 for (i
=buf
->start
; i
<(buf
->start
+buf
->size
); i
++) {
49 txbuf
[j
++]=SLIP_ESCEND
;
53 txbuf
[j
++]=SLIP_ESCESC
;
59 if ((j
+2)>DEFAULT_BUFSIZE
) {
60 if (write(fd
,txbuf
,j
)<0) {
61 fatal_perror("slip_stuff: write()");
67 if (write(fd
,txbuf
,j
)<0) {
68 fatal_perror("slip_stuff: write()");
73 static void slip_unstuff(struct slip
*st
, uint8_t *buf
, uint32_t l
)
77 BUF_ASSERT_USED(st
->buff
);
80 enum { OUTPUT_END
= 256, OUTPUT_NOTHING
= 257 };
83 buffer_init(st
->buff
,calculate_max_start_pad());
85 if (st
->pending_esc
) {
86 st
->pending_esc
=False
;
95 if (!st
->ignoring_packet
) {
96 Message(M_WARNING
, "userv_afterpoll: bad SLIP escape"
97 " character, dropping packet\n");
99 st
->ignoring_packet
=True
;
100 outputchr
=OUTPUT_NOTHING
;
106 outputchr
=OUTPUT_END
;
109 st
->pending_esc
=True
;
110 outputchr
=OUTPUT_NOTHING
;
118 if (st
->ignoring_packet
) {
119 if (outputchr
== OUTPUT_END
) {
120 st
->ignoring_packet
=False
;
124 if (outputchr
== OUTPUT_END
) {
125 if (st
->buff
->size
>0) {
126 st
->netlink_to_tunnel(&st
->nl
,st
->buff
);
127 BUF_ALLOC(st
->buff
,"userv_afterpoll");
130 } else if (outputchr
!= OUTPUT_NOTHING
) {
131 if (st
->buff
->size
< st
->buff
->len
) {
132 buf_append_uint8(st
->buff
,outputchr
);
134 Message(M_WARNING
, "userv_afterpoll: dropping overlong"
136 st
->ignoring_packet
=True
;
143 static void slip_init(struct slip
*st
, struct cloc loc
, dict_t
*dict
,
144 cstring_t name
, netlink_deliver_fn
*to_host
)
146 st
->netlink_to_tunnel
=
147 netlink_init(&st
->nl
,st
,loc
,dict
,
148 "netlink-userv-ipif",NULL
,to_host
);
149 st
->buff
=find_cl_if(dict
,"buffer",CL_BUFFER
,True
,"name",loc
);
150 st
->local_address
=string_item_to_ipaddr(
151 dict_find_item(dict
,"local-address", True
, name
, loc
),"netlink");
152 BUF_ALLOC(st
->buff
,"slip_init");
153 st
->pending_esc
=False
;
154 st
->ignoring_packet
=False
;
157 /* Connection to the kernel through userv-ipif */
161 int txfd
; /* We transmit to userv */
162 int rxfd
; /* We receive from userv */
163 cstring_t userv_path
;
164 cstring_t service_user
;
165 cstring_t service_name
;
167 bool_t expecting_userv_exit
;
170 static int userv_beforepoll(void *sst
, struct pollfd
*fds
, int *nfds_io
,
173 struct userv
*st
=sst
;
178 fds
[0].events
=0; /* Might want to pick up POLLOUT sometime */
180 fds
[1].events
=POLLIN
;
187 static void userv_afterpoll(void *sst
, struct pollfd
*fds
, int nfds
)
189 struct userv
*st
=sst
;
190 uint8_t rxbuf
[DEFAULT_BUFSIZE
];
195 if (fds
[1].revents
&POLLERR
) {
196 Message(M_ERR
,"%s: userv_afterpoll: POLLERR!\n",st
->slip
.nl
.name
);
198 if (fds
[1].revents
&POLLIN
) {
199 l
=read(st
->rxfd
,rxbuf
,DEFAULT_BUFSIZE
);
202 fatal_perror("%s: userv_afterpoll: read(rxfd)",
205 fatal("%s: userv_afterpoll: read(rxfd)=0; userv gone away?",
207 } else slip_unstuff(&st
->slip
,rxbuf
,l
);
211 /* Send buf to the kernel. Free buf before returning. */
212 static void userv_deliver_to_kernel(void *sst
, struct buffer_if
*buf
)
214 struct userv
*st
=sst
;
216 if (buf
->size
> st
->slip
.nl
.mtu
) {
217 Message(M_ERR
,"%s: packet of size %"PRIu32
" exceeds mtu %"PRIu32
":"
218 " cannot be injected into kernel, dropped\n",
219 st
->slip
.nl
.name
, buf
->size
, st
->slip
.nl
.mtu
);
224 slip_stuff(&st
->slip
,buf
,st
->txfd
);
227 static void userv_userv_callback(void *sst
, pid_t pid
, int status
)
229 struct userv
*st
=sst
;
232 Message(M_WARNING
,"userv_callback called unexpectedly with pid %d "
233 "(expected %d)\n",pid
,st
->pid
);
236 if (!st
->expecting_userv_exit
) {
237 if (WIFEXITED(status
)) {
238 fatal("%s: userv exited unexpectedly with status %d",
239 st
->slip
.nl
.name
,WEXITSTATUS(status
));
240 } else if (WIFSIGNALED(status
)) {
241 fatal("%s: userv exited unexpectedly: uncaught signal %d",
242 st
->slip
.nl
.name
,WTERMSIG(status
));
244 fatal("%s: userv stopped unexpectedly",
248 Message(M_WARNING
,"%s: userv subprocess died with status %d\n",
249 st
->slip
.nl
.name
,WEXITSTATUS(status
));
253 struct userv_entry_rec
{
258 /* XXX perhaps we should collect and log stderr? */
261 static void userv_entry(void *sst
)
263 struct userv_entry_rec
*st
=sst
;
268 /* XXX close all other fds */
270 /* XXX We really should strdup() all of argv[] but because we'll just
271 exit anyway if execvp() fails it doesn't seem worth bothering. */
272 execvp(st
->path
,(char *const*)st
->argv
);
273 perror("userv-entry: execvp()");
277 static void userv_invoke_userv(struct userv
*st
)
279 struct userv_entry_rec
*er
;
285 struct netlink_client
*r
;
286 struct ipset
*allnets
;
287 struct subnet_list
*snets
;
292 fatal("userv_invoke_userv: already running");
295 /* This is where we actually invoke userv - all the networks we'll
296 be using should already have been registered. */
298 addrs
=safe_malloc(512,"userv_invoke_userv:addrs");
299 snprintf(addrs
,512,"%s,%s,%d,slip",
300 ipaddr_to_string(st
->slip
.local_address
),
301 ipaddr_to_string(st
->slip
.nl
.secnet_address
),st
->slip
.nl
.mtu
);
304 for (r
=st
->slip
.nl
.clients
; r
; r
=r
->next
) {
305 if (r
->link_quality
> LINK_QUALITY_UNUSED
) {
308 nan
=ipset_union(allnets
,r
->networks
);
313 snets
=ipset_to_subnet_list(allnets
);
315 nets
=safe_malloc(20*snets
->entries
,"userv_invoke_userv:nets");
317 for (i
=0; i
<snets
->entries
; i
++) {
318 s
=subnet_to_string(snets
->list
[i
]);
323 nets
[strlen(nets
)-1]=0;
324 subnet_list_free(snets
);
326 Message(M_INFO
,"%s: about to invoke: %s %s %s %s %s\n",st
->slip
.nl
.name
,
327 st
->userv_path
,st
->service_user
,st
->service_name
,addrs
,nets
);
329 st
->slip
.pending_esc
=False
;
332 if (pipe(c_stdin
)!=0) {
333 fatal_perror("userv_invoke_userv: pipe(c_stdin)");
335 if (pipe(c_stdout
)!=0) {
336 fatal_perror("userv_invoke_userv: pipe(c_stdout)");
339 st
->rxfd
=c_stdout
[0];
341 er
=safe_malloc(sizeof(*r
),"userv_invoke_userv: er");
345 /* The arguments are:
349 local-addr,secnet-addr,mtu,protocol
351 er
->argv
=safe_malloc(sizeof(*er
->argv
)*6,"userv_invoke_userv:argv");
352 er
->argv
[0]=st
->userv_path
;
353 er
->argv
[1]=st
->service_user
;
354 er
->argv
[2]=st
->service_name
;
358 er
->path
=st
->userv_path
;
360 st
->pid
=makesubproc(userv_entry
, userv_userv_callback
,
361 er
, st
, st
->slip
.nl
.name
);
368 Message(M_INFO
,"%s: userv-ipif pid is %d\n",st
->slip
.nl
.name
,st
->pid
);
369 /* Read a single character from the pipe to confirm userv-ipif is
370 running. If we get a SIGCHLD at this point then we'll get EINTR. */
371 if ((nread
=read(st
->rxfd
,&confirm
,1))!=1) {
373 Message(M_WARNING
,"%s: read of confirmation byte was "
374 "interrupted\n",st
->slip
.nl
.name
);
377 fatal_perror("%s: error reading confirmation byte",
380 fatal("%s: unexpected EOF instead of confirmation byte"
381 " - userv ipif failed?", st
->slip
.nl
.name
);
385 if (confirm
!=SLIP_END
) {
386 fatal("%s: bad confirmation byte %d from userv-ipif",
387 st
->slip
.nl
.name
,confirm
);
392 static void userv_kill_userv(struct userv
*st
)
395 kill(-st
->pid
,SIGTERM
);
396 st
->expecting_userv_exit
=True
;
400 static void userv_phase_hook(void *sst
, uint32_t newphase
)
402 struct userv
*st
=sst
;
403 /* We must wait until signal processing has started before forking
405 if (newphase
==PHASE_RUN
) {
406 userv_invoke_userv(st
);
407 /* Register for poll() */
408 register_for_poll(st
, userv_beforepoll
, userv_afterpoll
, 2,
411 if (newphase
==PHASE_SHUTDOWN
) {
412 userv_kill_userv(st
);
416 static list_t
*userv_apply(closure_t
*self
, struct cloc loc
, dict_t
*context
,
423 st
=safe_malloc(sizeof(*st
),"userv_apply");
425 /* First parameter must be a dict */
426 item
=list_elem(args
,0);
427 if (!item
|| item
->type
!=t_dict
)
428 cfgfatal(loc
,"userv-ipif","parameter must be a dictionary\n");
430 dict
=item
->data
.dict
;
432 slip_init(&st
->slip
,loc
,dict
,"netlink-userv-ipif",
433 userv_deliver_to_kernel
);
435 st
->userv_path
=dict_read_string(dict
,"userv-path",False
,"userv-netlink",
437 st
->service_user
=dict_read_string(dict
,"service-user",False
,
438 "userv-netlink",loc
);
439 st
->service_name
=dict_read_string(dict
,"service-name",False
,
440 "userv-netlink",loc
);
441 if (!st
->userv_path
) st
->userv_path
="userv";
442 if (!st
->service_user
) st
->service_user
="root";
443 if (!st
->service_name
) st
->service_name
="ipif";
444 st
->rxfd
=-1; st
->txfd
=-1;
446 st
->expecting_userv_exit
=False
;
447 add_hook(PHASE_RUN
,userv_phase_hook
,st
);
448 add_hook(PHASE_SHUTDOWN
,userv_phase_hook
,st
);
450 return new_closure(&st
->slip
.nl
.cl
);
453 void slip_module(dict_t
*dict
)
455 add_closure(dict
,"userv-ipif",userv_apply
);