1398a5aebSmckusick /*
2398a5aebSmckusick * Copyright (c) 1989 Jan-Simon Pendry
3398a5aebSmckusick * Copyright (c) 1989 Imperial College of Science, Technology & Medicine
4*4092c5ccSbostic * Copyright (c) 1989, 1993
5*4092c5ccSbostic * The Regents of the University of California. All rights reserved.
6398a5aebSmckusick *
7398a5aebSmckusick * This code is derived from software contributed to Berkeley by
8398a5aebSmckusick * Jan-Simon Pendry at Imperial College, London.
9398a5aebSmckusick *
10398a5aebSmckusick * %sccs.include.redist.c%
11398a5aebSmckusick *
12*4092c5ccSbostic * @(#)rpc_fwd.c 8.1 (Berkeley) 06/06/93
13c626267eSpendry *
14cc0207dcSpendry * $Id: rpc_fwd.c,v 5.2.2.1 1992/02/09 15:09:01 jsp beta $
15c626267eSpendry *
16398a5aebSmckusick */
17398a5aebSmckusick
18398a5aebSmckusick /*
19398a5aebSmckusick * RPC packet forwarding
20398a5aebSmckusick */
21398a5aebSmckusick
22398a5aebSmckusick #include "am.h"
23398a5aebSmckusick #include <sys/ioctl.h>
24398a5aebSmckusick #ifndef F_SETFL
25398a5aebSmckusick #include <fcntl.h>
26398a5aebSmckusick #endif /* F_SETFL */
27398a5aebSmckusick #ifndef FNDELAY
28398a5aebSmckusick #include <sys/file.h>
29398a5aebSmckusick #endif /* FNDELAY */
30398a5aebSmckusick
31398a5aebSmckusick /*
32398a5aebSmckusick * Note that the ID field in the external packet is only
33398a5aebSmckusick * ever treated as a 32 bit opaque data object, so there
34398a5aebSmckusick * is no need to convert to and from network byte ordering.
35398a5aebSmckusick */
36398a5aebSmckusick
37398a5aebSmckusick /*
38398a5aebSmckusick * Each pending reply has an rpc_forward structure
39398a5aebSmckusick * associated with it. These have a 15 second lifespan.
40398a5aebSmckusick * If a new structure is required, then an expired
41398a5aebSmckusick * one will be re-allocated if available, otherwise a fresh
42398a5aebSmckusick * one is allocated. Whenever a reply is received the
43398a5aebSmckusick * structure is discarded.
44398a5aebSmckusick */
45398a5aebSmckusick typedef struct rpc_forward rpc_forward;
46398a5aebSmckusick struct rpc_forward {
47398a5aebSmckusick qelem rf_q; /* Linked list */
48398a5aebSmckusick time_t rf_ttl; /* Time to live */
49398a5aebSmckusick u_int rf_xid; /* Packet id */
50398a5aebSmckusick u_int rf_oldid; /* Original packet id */
51398a5aebSmckusick fwd_fun rf_fwd; /* Forwarding function */
52398a5aebSmckusick voidp rf_ptr;
53398a5aebSmckusick struct sockaddr_in rf_sin;
54398a5aebSmckusick };
55398a5aebSmckusick
56398a5aebSmckusick /*
57398a5aebSmckusick * Head of list of pending replies
58398a5aebSmckusick */
59398a5aebSmckusick extern qelem rpc_head;
60398a5aebSmckusick qelem rpc_head = { &rpc_head, &rpc_head };
61398a5aebSmckusick
62398a5aebSmckusick static u_int xid;
63398a5aebSmckusick #define XID_ALLOC() (xid++)
64398a5aebSmckusick
65398a5aebSmckusick #define MAX_PACKET_SIZE 8192 /* Maximum UDP packet size */
66398a5aebSmckusick
67398a5aebSmckusick int fwd_sock;
68398a5aebSmckusick
69398a5aebSmckusick /*
70398a5aebSmckusick * Allocate a rely structure
71398a5aebSmckusick */
fwd_alloc()72398a5aebSmckusick static rpc_forward *fwd_alloc()
73398a5aebSmckusick {
74398a5aebSmckusick time_t now = clocktime();
75398a5aebSmckusick rpc_forward *p = 0, *p2;
76398a5aebSmckusick
77398a5aebSmckusick #ifdef DEBUG
78398a5aebSmckusick /*dlog("fwd_alloca: rpc_head = %#x", rpc_head.q_forw);*/
79398a5aebSmckusick #endif /* DEBUG */
80398a5aebSmckusick /*
81398a5aebSmckusick * First search for an existing expired one.
82398a5aebSmckusick */
83398a5aebSmckusick ITER(p2, rpc_forward, &rpc_head) {
84398a5aebSmckusick if (p2->rf_ttl <= now) {
85398a5aebSmckusick p = p2;
86398a5aebSmckusick break;
87398a5aebSmckusick }
88398a5aebSmckusick }
89398a5aebSmckusick
90398a5aebSmckusick /*
91398a5aebSmckusick * If one couldn't be found then allocate
92398a5aebSmckusick * a new structure and link it at the
93398a5aebSmckusick * head of the list.
94398a5aebSmckusick */
95398a5aebSmckusick if (p) {
96398a5aebSmckusick /*
97398a5aebSmckusick * Call forwarding function to say that
98398a5aebSmckusick * this message was junked.
99398a5aebSmckusick */
100398a5aebSmckusick #ifdef DEBUG
101398a5aebSmckusick dlog("Re-using packet forwarding slot - id %#x", p->rf_xid);
102398a5aebSmckusick #endif /* DEBUG */
103398a5aebSmckusick if (p->rf_fwd)
104398a5aebSmckusick (*p->rf_fwd)(0, 0, 0, &p->rf_sin, p->rf_ptr, FALSE);
105398a5aebSmckusick rem_que(&p->rf_q);
106398a5aebSmckusick } else {
107398a5aebSmckusick p = ALLOC(rpc_forward);
108398a5aebSmckusick }
109398a5aebSmckusick ins_que(&p->rf_q, &rpc_head);
110398a5aebSmckusick
111398a5aebSmckusick /*
112398a5aebSmckusick * Set the time to live field
113398a5aebSmckusick * Timeout in 43 seconds
114398a5aebSmckusick */
115398a5aebSmckusick p->rf_ttl = now + 43;
116398a5aebSmckusick
117398a5aebSmckusick #ifdef DEBUG
118398a5aebSmckusick /*dlog("fwd_alloca: rpc_head = %#x", rpc_head.q_forw);*/
119398a5aebSmckusick #endif /* DEBUG */
120398a5aebSmckusick return p;
121398a5aebSmckusick }
122398a5aebSmckusick
123398a5aebSmckusick /*
124398a5aebSmckusick * Free an allocated reply structure.
125398a5aebSmckusick * First unlink it from the list, then
126398a5aebSmckusick * discard it.
127398a5aebSmckusick */
fwd_free(p)128398a5aebSmckusick static void fwd_free(p)
129398a5aebSmckusick rpc_forward *p;
130398a5aebSmckusick {
131398a5aebSmckusick #ifdef DEBUG
132398a5aebSmckusick /*dlog("fwd_free: rpc_head = %#x", rpc_head.q_forw);*/
133398a5aebSmckusick #endif /* DEBUG */
134398a5aebSmckusick rem_que(&p->rf_q);
135398a5aebSmckusick #ifdef DEBUG
136398a5aebSmckusick /*dlog("fwd_free: rpc_head = %#x", rpc_head.q_forw);*/
137398a5aebSmckusick #endif /* DEBUG */
1388a89c22cSpendry free((voidp) p);
139398a5aebSmckusick }
140398a5aebSmckusick
141398a5aebSmckusick /*
142398a5aebSmckusick * Initialise the RPC forwarder
143398a5aebSmckusick */
fwd_init()144398a5aebSmckusick int fwd_init()
145398a5aebSmckusick {
146398a5aebSmckusick int on = 1;
147398a5aebSmckusick
148398a5aebSmckusick /*
149398a5aebSmckusick * Create ping socket
150398a5aebSmckusick */
151398a5aebSmckusick fwd_sock = socket(AF_INET, SOCK_DGRAM, 0);
152398a5aebSmckusick if (fwd_sock < 0) {
153398a5aebSmckusick plog(XLOG_ERROR, "Unable to create RPC forwarding socket: %m");
154398a5aebSmckusick return errno;
155398a5aebSmckusick }
156398a5aebSmckusick
157398a5aebSmckusick /*
158398a5aebSmckusick * Some things we talk to require a priv port - so make one here
159398a5aebSmckusick */
160398a5aebSmckusick if (bind_resv_port(fwd_sock, (unsigned short *) 0) < 0)
161398a5aebSmckusick plog(XLOG_ERROR, "can't bind privileged port");
162398a5aebSmckusick
163398a5aebSmckusick if (fcntl(fwd_sock, F_SETFL, FNDELAY) < 0 &&
164398a5aebSmckusick ioctl(fwd_sock, FIONBIO, &on) < 0) {
165398a5aebSmckusick plog(XLOG_ERROR, "Can't set non-block on forwarding socket: %m");
166398a5aebSmckusick return errno;
167398a5aebSmckusick }
168398a5aebSmckusick
169398a5aebSmckusick return 0;
170398a5aebSmckusick }
171398a5aebSmckusick
172398a5aebSmckusick /*
173398a5aebSmckusick * Locate a packet in the forwarding list
174398a5aebSmckusick */
fwd_locate(id)175398a5aebSmckusick static rpc_forward *fwd_locate(id)
176398a5aebSmckusick u_int id;
177398a5aebSmckusick {
178398a5aebSmckusick rpc_forward *p;
179398a5aebSmckusick
180398a5aebSmckusick ITER(p, rpc_forward, &rpc_head) {
181398a5aebSmckusick if (p->rf_xid == id)
182398a5aebSmckusick return p;
183398a5aebSmckusick }
184398a5aebSmckusick
185398a5aebSmckusick return 0;
186398a5aebSmckusick }
187398a5aebSmckusick
188398a5aebSmckusick /*
189398a5aebSmckusick * This is called to forward a packet to another
190398a5aebSmckusick * RPC server. The message id is changed and noted
191398a5aebSmckusick * so that when a reply appears we can tie it up
192398a5aebSmckusick * correctly. Just matching the reply's source address
193398a5aebSmckusick * would not work because it might come from a
194398a5aebSmckusick * different address.
195398a5aebSmckusick */
fwd_packet(type_id,pkt,len,fwdto,replyto,i,cb)196398a5aebSmckusick int fwd_packet(type_id, pkt, len, fwdto, replyto, i, cb)
197398a5aebSmckusick int type_id;
198398a5aebSmckusick voidp pkt;
199398a5aebSmckusick int len;
200398a5aebSmckusick struct sockaddr_in *fwdto, *replyto;
201398a5aebSmckusick voidp i;
202398a5aebSmckusick fwd_fun cb;
203398a5aebSmckusick {
204398a5aebSmckusick rpc_forward *p;
205398a5aebSmckusick u_int *pkt_int;
206398a5aebSmckusick int error;
207398a5aebSmckusick
208398a5aebSmckusick if ((int)amd_state >= (int)Finishing)
209398a5aebSmckusick return ENOENT;
210398a5aebSmckusick
211398a5aebSmckusick /*
212398a5aebSmckusick * See if the type_id is fully specified.
213398a5aebSmckusick * If so, then discard any old entries
214398a5aebSmckusick * for this id.
215398a5aebSmckusick * Otherwise make sure the type_id is
216398a5aebSmckusick * fully qualified by allocating an id here.
217398a5aebSmckusick */
218398a5aebSmckusick #ifdef DEBUG
219398a5aebSmckusick switch (type_id & RPC_XID_MASK) {
220398a5aebSmckusick case RPC_XID_PORTMAP: dlog("Sending PORTMAP request"); break;
221398a5aebSmckusick case RPC_XID_MOUNTD: dlog("Sending MOUNTD request %#x", type_id); break;
222398a5aebSmckusick case RPC_XID_NFSPING: dlog("Sending NFS ping"); break;
223398a5aebSmckusick default: dlog("UNKNOWN RPC XID"); break;
224398a5aebSmckusick }
225398a5aebSmckusick #endif /* DEBUG */
226398a5aebSmckusick
227398a5aebSmckusick if (type_id & ~RPC_XID_MASK) {
228398a5aebSmckusick #ifdef DEBUG
229398a5aebSmckusick /*dlog("Fully qualified rpc type provided");*/
230398a5aebSmckusick #endif /* DEBUG */
231398a5aebSmckusick p = fwd_locate(type_id);
232398a5aebSmckusick if (p) {
233398a5aebSmckusick #ifdef DEBUG
234398a5aebSmckusick dlog("Discarding earlier rpc fwd handle");
235398a5aebSmckusick #endif /* DEBUG */
236398a5aebSmckusick fwd_free(p);
237398a5aebSmckusick }
238398a5aebSmckusick } else {
239398a5aebSmckusick #ifdef DEBUG
240398a5aebSmckusick dlog("Allocating a new xid...");
241398a5aebSmckusick #endif /* DEBUG */
242398a5aebSmckusick type_id = MK_RPC_XID(type_id, XID_ALLOC());
243398a5aebSmckusick }
244398a5aebSmckusick
245398a5aebSmckusick p = fwd_alloc();
246398a5aebSmckusick if (!p)
247398a5aebSmckusick return ENOBUFS;
248398a5aebSmckusick
249398a5aebSmckusick error = 0;
250398a5aebSmckusick
251398a5aebSmckusick pkt_int = (u_int *) pkt;
252398a5aebSmckusick
253398a5aebSmckusick /*
254398a5aebSmckusick * Get the original packet id
255398a5aebSmckusick */
256398a5aebSmckusick p->rf_oldid = *pkt_int;
257398a5aebSmckusick
258398a5aebSmckusick /*
259398a5aebSmckusick * Replace with newly allocated id
260398a5aebSmckusick */
261398a5aebSmckusick p->rf_xid = *pkt_int = type_id;
262398a5aebSmckusick
263398a5aebSmckusick /*
264398a5aebSmckusick * The sendto may fail if, for example, the route
265398a5aebSmckusick * to a remote host is lost because an intermediate
266398a5aebSmckusick * gateway has gone down. Important to fill in the
267398a5aebSmckusick * rest of "p" otherwise nasty things happen later...
268398a5aebSmckusick */
269398a5aebSmckusick #ifdef DEBUG
2708a89c22cSpendry { char dq[20];
2718a89c22cSpendry dlog("Sending packet id %#x to %s.%d", p->rf_xid, inet_dquad(dq, fwdto->sin_addr.s_addr), ntohs(fwdto->sin_port));
2728a89c22cSpendry }
273398a5aebSmckusick #endif /* DEBUG */
274398a5aebSmckusick if (sendto(fwd_sock, (char *) pkt, len, 0,
275398a5aebSmckusick (struct sockaddr *) fwdto, sizeof(*fwdto)) < 0)
276398a5aebSmckusick error = errno;
277398a5aebSmckusick
278398a5aebSmckusick /*
279398a5aebSmckusick * Save callback function and return address
280398a5aebSmckusick */
281398a5aebSmckusick p->rf_fwd = cb;
282398a5aebSmckusick if (replyto)
283398a5aebSmckusick p->rf_sin = *replyto;
284398a5aebSmckusick else
285398a5aebSmckusick bzero((voidp) &p->rf_sin, sizeof(p->rf_sin));
286398a5aebSmckusick p->rf_ptr = i;
287398a5aebSmckusick
288398a5aebSmckusick return error;
289398a5aebSmckusick }
290398a5aebSmckusick
291398a5aebSmckusick /*
292398a5aebSmckusick * Called when some data arrives on the forwarding socket
293398a5aebSmckusick */
fwd_reply()294398a5aebSmckusick void fwd_reply()
295398a5aebSmckusick {
296398a5aebSmckusick int len;
297398a5aebSmckusick #ifdef DYNAMIC_BUFFERS
298398a5aebSmckusick voidp pkt;
299398a5aebSmckusick #else
300398a5aebSmckusick u_int pkt[MAX_PACKET_SIZE/sizeof(u_int)+1];
301398a5aebSmckusick #endif /* DYNAMIC_BUFFERS */
302398a5aebSmckusick u_int *pkt_int;
303398a5aebSmckusick int rc;
304398a5aebSmckusick rpc_forward *p;
305398a5aebSmckusick struct sockaddr_in src_addr;
306398a5aebSmckusick int src_addr_len;
307398a5aebSmckusick
308398a5aebSmckusick /*
309398a5aebSmckusick * Determine the length of the packet
310398a5aebSmckusick */
311398a5aebSmckusick #ifdef DYNAMIC_BUFFERS
312398a5aebSmckusick if (ioctl(fwd_sock, FIONREAD, &len) < 0) {
313398a5aebSmckusick plog(XLOG_ERROR, "Error reading packet size: %m");
314398a5aebSmckusick return;
315398a5aebSmckusick }
316398a5aebSmckusick
317398a5aebSmckusick /*
318398a5aebSmckusick * Allocate a buffer
319398a5aebSmckusick */
320398a5aebSmckusick pkt = (voidp) malloc((unsigned) len);
321398a5aebSmckusick if (!pkt) {
322398a5aebSmckusick plog(XLOG_ERROR, "Out of buffers in fwd_reply");
323398a5aebSmckusick return;
324398a5aebSmckusick }
325398a5aebSmckusick #else
326398a5aebSmckusick len = MAX_PACKET_SIZE;
327398a5aebSmckusick #endif /* DYNAMIC_BUFFERS */
328398a5aebSmckusick
329398a5aebSmckusick /*
330398a5aebSmckusick * Read the packet and check for validity
331398a5aebSmckusick */
332398a5aebSmckusick again:
333398a5aebSmckusick src_addr_len = sizeof(src_addr);
334398a5aebSmckusick rc = recvfrom(fwd_sock, (char *) pkt, len, 0,
335398a5aebSmckusick (struct sockaddr *) &src_addr, &src_addr_len);
336398a5aebSmckusick if (rc < 0 || src_addr_len != sizeof(src_addr) ||
337398a5aebSmckusick src_addr.sin_family != AF_INET) {
338398a5aebSmckusick if (rc < 0 && errno == EINTR)
339398a5aebSmckusick goto again;
340398a5aebSmckusick plog(XLOG_ERROR, "Error reading RPC reply: %m");
341398a5aebSmckusick goto out;
342398a5aebSmckusick }
343398a5aebSmckusick
344398a5aebSmckusick #ifdef DYNAMIC_BUFFERS
345398a5aebSmckusick if (rc != len) {
346398a5aebSmckusick plog(XLOG_ERROR, "Short read in fwd_reply");
347398a5aebSmckusick goto out;
348398a5aebSmckusick }
349398a5aebSmckusick #endif /* DYNAMIC_BUFFERS */
350398a5aebSmckusick
351398a5aebSmckusick /*
352398a5aebSmckusick * Do no more work if finishing soon
353398a5aebSmckusick */
354398a5aebSmckusick if ((int)amd_state >= (int)Finishing)
355398a5aebSmckusick goto out;
356398a5aebSmckusick
357398a5aebSmckusick /*
358398a5aebSmckusick * Find packet reference
359398a5aebSmckusick */
360398a5aebSmckusick pkt_int = (u_int *) pkt;
361398a5aebSmckusick
362398a5aebSmckusick #ifdef DEBUG
363398a5aebSmckusick switch (*pkt_int & RPC_XID_MASK) {
364398a5aebSmckusick case RPC_XID_PORTMAP: dlog("Receiving PORTMAP reply"); break;
365398a5aebSmckusick case RPC_XID_MOUNTD: dlog("Receiving MOUNTD reply %#x", *pkt_int); break;
366398a5aebSmckusick case RPC_XID_NFSPING: dlog("Receiving NFS ping %#x", *pkt_int); break;
367398a5aebSmckusick default: dlog("UNKNOWN RPC XID"); break;
368398a5aebSmckusick }
369398a5aebSmckusick #endif /* DEBUG */
370398a5aebSmckusick
371398a5aebSmckusick p = fwd_locate(*pkt_int);
372398a5aebSmckusick if (!p) {
373398a5aebSmckusick #ifdef DEBUG
374398a5aebSmckusick dlog("Can't forward reply id %#x", *pkt_int);
375398a5aebSmckusick #endif /* DEBUG */
376398a5aebSmckusick goto out;
377398a5aebSmckusick }
378398a5aebSmckusick
379398a5aebSmckusick if (p->rf_fwd) {
380398a5aebSmckusick /*
381398a5aebSmckusick * Put the original message id back
382398a5aebSmckusick * into the packet.
383398a5aebSmckusick */
384398a5aebSmckusick *pkt_int = p->rf_oldid;
385398a5aebSmckusick
386398a5aebSmckusick /*
387398a5aebSmckusick * Call forwarding function
388398a5aebSmckusick */
3898a89c22cSpendry (*p->rf_fwd)((voidp) pkt, rc, &src_addr, &p->rf_sin, p->rf_ptr, TRUE);
390398a5aebSmckusick }
391398a5aebSmckusick
392398a5aebSmckusick /*
393398a5aebSmckusick * Free forwarding info
394398a5aebSmckusick */
395398a5aebSmckusick fwd_free(p);
396398a5aebSmckusick
397398a5aebSmckusick out:;
398398a5aebSmckusick #ifdef DYNAMIC_BUFFERS
399398a5aebSmckusick /*
400398a5aebSmckusick * Free the packet
401398a5aebSmckusick */
4028a89c22cSpendry free((voidp) pkt);
403398a5aebSmckusick #endif /* DYNAMIC_BUFFERS */
404398a5aebSmckusick }
405