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1 | /* | |
2 | * $Source$ | |
3 | * $Author$ | |
4 | * $Header$ | |
5 | * | |
6 | * Copyright (C) 1987, 1988 by the Massachusetts Institute of Technology | |
7 | * For copying and distribution information, please see the file | |
8 | * <mit-copyright.h>. | |
9 | * | |
10 | * Server for user registration with Moira and Kerberos. | |
11 | * | |
12 | * This file handles the processing of requests for the register | |
13 | * server. | |
14 | */ | |
15 | ||
16 | #ifndef lint | |
17 | static char *rcsid_requests_c = "$Header$"; | |
18 | #endif lint | |
19 | ||
20 | /* | |
21 | * Before you add anything to the list of things that are #included and | |
22 | * #defined, make sure that it is not already done in reg_svr.h | |
23 | */ | |
24 | ||
25 | #include <mit-copyright.h> | |
26 | #include <stdio.h> | |
27 | #include <strings.h> | |
28 | #include <ctype.h> | |
29 | #include <sys/types.h> | |
30 | #include <sys/file.h> | |
31 | #include <krb.h> | |
32 | #include <des.h> | |
33 | #include <errno.h> | |
34 | #include <sys/socket.h> | |
35 | #include <netinet/in.h> | |
36 | #include <netdb.h> | |
37 | #include "moira.h" | |
38 | #include "moira_site.h" | |
39 | #include "reg_svr.h" | |
40 | ||
41 | #define NUM_REQUESTS_SAVED 100 /* Number of transactions to save */ | |
42 | #define CUR_REQ (requests[cur_request_index]) /* The current request */ | |
43 | #define NEXT_INDEX(x) (x == NUM_REQUESTS_SAVED - 1) ? 0 : (x + 1) | |
44 | #define PREV_INDEX(x) (x == 0) ? (NUM_REQUESTS_SAVED - 1) : (x - 1) | |
45 | ||
46 | static struct servent *sp; /* Service info from /etc/services */ | |
47 | static int s; /* Socket descriptor */ | |
48 | static struct sockaddr_in sin; /* Internet style socket address */ | |
49 | static int addrlen; /* Size of socket address (sin) */ | |
50 | ||
51 | /* In order to elegantly handle multiple retransmissions, an instance | |
52 | of this structure will be retained for the last NUM_REQUESTS_SAVED | |
53 | transactions with the client. */ | |
54 | struct request_save { | |
55 | char out_pkt[BUFSIZ]; /* Buffer for outgoing packet */ | |
56 | int out_pktlen; /* Length of outgoing packet */ | |
57 | U_32BIT seqno; /* Sequence number for packet transmission */ | |
58 | u_long ip_address; /* Internet address of client host */ | |
59 | u_short cl_port; /* Port number client used */ | |
60 | }; | |
61 | ||
62 | static struct request_save requests[NUM_REQUESTS_SAVED]; /* Saved packets */ | |
63 | static int cur_request_index = 0; /* Index to the current request */ | |
64 | ||
65 | void clear_req(struct request_save *req) | |
66 | { | |
67 | req->seqno = 0; | |
68 | req->ip_address = 0; | |
69 | req->cl_port = 0; | |
70 | } | |
71 | ||
72 | void req_initialize(void) | |
73 | { | |
74 | register int i; | |
75 | ||
76 | /* Get service information from /etc/services */ | |
77 | if (!(sp = getservbyname("sms_ureg", "udp"))) | |
78 | { | |
79 | com_err(whoami, errno, " unknown service sms_ureg/udp"); | |
80 | exit(1); | |
81 | } | |
82 | ||
83 | /* Get an internet style datagram socket */ | |
84 | if ((s = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP)) < 0) | |
85 | { | |
86 | com_err(whoami, errno, " socket"); | |
87 | exit(1); | |
88 | } | |
89 | memset(&sin, 0, sizeof(sin)); | |
90 | ||
91 | sin.sin_family = AF_INET; | |
92 | sin.sin_port = sp->s_port; | |
93 | sin.sin_addr.s_addr = INADDR_ANY; | |
94 | ||
95 | /* Bind a name to the socket */ | |
96 | if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) | |
97 | { | |
98 | com_err(whoami, errno, " bind"); | |
99 | exit(1); | |
100 | } | |
101 | ||
102 | for (i = 0; i < NUM_REQUESTS_SAVED; i++) | |
103 | clear_req(&(requests[i])); | |
104 | } | |
105 | ||
106 | int handle_retransmitted(void) | |
107 | { | |
108 | register int i; /* A counter */ | |
109 | int status = FALSE; /* Return status */ | |
110 | ||
111 | for (i = PREV_INDEX(cur_request_index); i != cur_request_index; | |
112 | i = PREV_INDEX(i)) | |
113 | { | |
114 | if ((requests[i].seqno == CUR_REQ.seqno) && | |
115 | (requests[i].ip_address == sin.sin_addr.s_addr) && | |
116 | (requests[i].cl_port == sin.sin_port)) | |
117 | /* This is a retransmitted packet */ | |
118 | { | |
119 | status = TRUE; | |
120 | sendto(s, requests[i].out_pkt, requests[i].out_pktlen, | |
121 | 0, (struct sockaddr *)&sin, addrlen); | |
122 | break; | |
123 | } | |
124 | } | |
125 | ||
126 | return status; | |
127 | } | |
128 | ||
129 | /* This routine takes care of sending packets back to the client and | |
130 | caching the necessary information for retransmission detection. | |
131 | It is the only place in which cur_request_index should be | |
132 | changed. */ | |
133 | void respond(int status, char *text) | |
134 | { | |
135 | CUR_REQ.out_pktlen = sizeof(CUR_REQ.out_pkt); | |
136 | ||
137 | if (format_pkt(CUR_REQ.out_pkt, &(CUR_REQ.out_pktlen), | |
138 | CUR_REQ.seqno, status, text)) | |
139 | com_err(whoami, 0, "Client error message was truncated."); | |
140 | sendto(s, CUR_REQ.out_pkt, CUR_REQ.out_pktlen, 0, | |
141 | (struct sockaddr *)&sin, addrlen); | |
142 | ||
143 | cur_request_index = NEXT_INDEX(cur_request_index); | |
144 | } | |
145 | ||
146 | void get_request(struct msg *message) | |
147 | { | |
148 | static char packet[BUFSIZ]; /* Buffer for incoming packet */ | |
149 | int pktlen; /* Length of incoming packet */ | |
150 | int status = FAILURE; /* Error status */ | |
151 | ||
152 | /* Sit around waiting for requests from the client. */ | |
153 | for (;;) | |
154 | { | |
155 | com_err(whoami, 0, "*** Ready for next request ***"); | |
156 | addrlen = sizeof(sin); | |
157 | /* Receive a packet */ | |
158 | if ((pktlen = recvfrom(s, packet, sizeof(packet), 0, | |
159 | (struct sockaddr *)&sin, &addrlen)) < 0) | |
160 | { | |
161 | com_err(whoami, errno, " recvfrom"); | |
162 | /* Don't worry if error is interrupted system call. */ | |
163 | if (errno == EINTR) | |
164 | continue; | |
165 | exit(1); | |
166 | } | |
167 | ||
168 | /* Store available information */ | |
169 | CUR_REQ.seqno = 0; | |
170 | CUR_REQ.ip_address = sin.sin_addr.s_addr; | |
171 | CUR_REQ.cl_port = sin.sin_port; | |
172 | ||
173 | /* Parse a request packet and save sequence number */ | |
174 | if ((status = parse_pkt(packet, pktlen, message)) != SUCCESS) | |
175 | { | |
176 | /* If error, format packet to send back to the client */ | |
177 | respond(status, NULL); | |
178 | } | |
179 | else | |
180 | { | |
181 | /* Check for retransmitted packet. handle_retransmitted() | |
182 | returns true if it handled a retransmitted packet. */ | |
183 | if (!handle_retransmitted()) | |
184 | break; | |
185 | } | |
186 | } | |
187 | } | |
188 | ||
189 | void report(int status, char *message) | |
190 | { | |
191 | respond(status, message); | |
192 | } | |
193 | ||
194 | /* This routine prepares a packet to send back to the client. A | |
195 | non-zero return status means that the client error message was | |
196 | truncated. */ | |
197 | int format_pkt(char *packet, int *pktlenp, U_32BIT seqno, | |
198 | int cl_status, char *message) | |
199 | { | |
200 | int len; /* Amount of message to send */ | |
201 | int status = SUCCESS; /* Return status */ | |
202 | ||
203 | /* Convert byte order to network byte order */ | |
204 | U_32BIT vers = htonl((U_32BIT)CUR_UREG_VERSION); | |
205 | cl_status = htonl((U_32BIT)cl_status); | |
206 | /* Put current user registration protocol version into the packet */ | |
207 | memcpy(packet, &vers, sizeof(U_32BIT)); | |
208 | /* Put sequence number into the packet */ | |
209 | memcpy(packet + sizeof(U_32BIT), &seqno, sizeof(U_32BIT)); | |
210 | /* Put error status into the packet */ | |
211 | memcpy(packet + 2 * sizeof(U_32BIT), &cl_status, sizeof(U_32BIT)); | |
212 | ||
213 | /* Find out how much of the message to copy; truncate if too short. */ | |
214 | /* How much room is there left? */ | |
215 | len = *pktlenp - sizeof(U_32BIT) * 3; | |
216 | if (!message) | |
217 | message = ""; | |
218 | if (len < strlen(message) + 1) /* Room for null terminator */ | |
219 | { | |
220 | status = FAILURE; /* Message was truncated */ | |
221 | /* Truncate the message */ | |
222 | message[len - 1] = '\0'; | |
223 | } | |
224 | ||
225 | /* Copy the message into the packet */ | |
226 | strcpy(packet + 3 * sizeof(U_32BIT), message); | |
227 | *pktlenp = 3 * sizeof(U_32BIT) + strlen(message); | |
228 | ||
229 | return status; | |
230 | } | |
231 | ||
232 | /* The ureg_validate_char variable and routine were taken verbatim | |
233 | out of server/qsupport.qc where they are called | |
234 | validate_chars. At some point, it may be desirable | |
235 | to put this functionality in one place. */ | |
236 | ||
237 | /* ureg_validate_char: verify that there are no illegal characters in | |
238 | * the string. Legal characters are printing chars other than | |
239 | * ", *, ?, \, [ and ]. | |
240 | */ | |
241 | static int illegalchars[] = { | |
242 | 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* ^@ - ^O */ | |
243 | 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* ^P - ^_ */ | |
244 | 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, /* SPACE - / */ | |
245 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, /* 0 - ? */ | |
246 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* @ - O */ | |
247 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, /* P - _ */ | |
248 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* ` - o */ | |
249 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, /* p - ^? */ | |
250 | 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
251 | 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
252 | 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
253 | 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
254 | 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
255 | 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
256 | 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
257 | 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
258 | }; | |
259 | ||
260 | int ureg_validate_char(register char *s) | |
261 | { | |
262 | while (*s) | |
263 | { | |
264 | if (illegalchars[*s++]) | |
265 | return FAILURE; | |
266 | } | |
267 | return SUCCESS; | |
268 | } | |
269 | ||
270 | /* This routine checks a packet and puts the information in it in | |
271 | a structure if it is valid. It also saves the sequence number | |
272 | in the list of saved requests. */ | |
273 | int parse_pkt(char *packet, int pktlen, struct msg *message) | |
274 | { | |
275 | int status = SUCCESS; /* Error status */ | |
276 | ||
277 | com_err(whoami, 0, "Packet received"); | |
278 | ||
279 | if (pktlen < sizeof(U_32BIT)) | |
280 | status = UREG_BROKEN_PACKET; | |
281 | if (status == SUCCESS) | |
282 | { | |
283 | /* Extract the user registration protocol version from the packet */ | |
284 | memcpy(&message->version, packet, sizeof(long)); | |
285 | /* Convert byte order from network to host */ | |
286 | message->version = ntohl(message->version); | |
287 | /* Verify version */ | |
288 | if (message->version != CUR_UREG_VERSION) | |
289 | status = UREG_WRONG_VERSION; | |
290 | } | |
291 | ||
292 | if (status == SUCCESS) | |
293 | { | |
294 | packet += sizeof(U_32BIT); | |
295 | pktlen -= sizeof(U_32BIT); | |
296 | ||
297 | if (pktlen < sizeof(U_32BIT)) | |
298 | status = UREG_BROKEN_PACKET; | |
299 | } | |
300 | ||
301 | if (status == SUCCESS) | |
302 | { | |
303 | /* Extract the sequence number from the packet */ | |
304 | memcpy(&CUR_REQ.seqno, packet, sizeof(long)); | |
305 | ||
306 | packet += sizeof(U_32BIT); | |
307 | pktlen -= sizeof(U_32BIT); | |
308 | ||
309 | if (pktlen < sizeof(U_32BIT)) | |
310 | status = UREG_BROKEN_PACKET; | |
311 | } | |
312 | ||
313 | if (status == SUCCESS) | |
314 | { | |
315 | /* Extract the request from the packet */ | |
316 | memcpy(&message->request, packet, sizeof(U_32BIT)); | |
317 | message->request = ntohl(message->request); | |
318 | packet += sizeof(U_32BIT); | |
319 | pktlen -= sizeof(U_32BIT); | |
320 | ||
321 | /* Make sure that the packet contains only valid characters up | |
322 | to the next null */ | |
323 | if (ureg_validate_char(packet) != SUCCESS) | |
324 | { | |
325 | com_err(whoami, 0, "Packet contains invalid characters."); | |
326 | status = UREG_USER_NOT_FOUND; | |
327 | } | |
328 | else | |
329 | { | |
330 | /* Extract first name from the packet */ | |
331 | message->first = packet; | |
332 | ||
333 | /* Scan forward until null appears in the packet or there | |
334 | is no more packet! */ | |
335 | for (; *packet && pktlen > 0; --pktlen, ++packet) | |
336 | continue; | |
337 | if (pktlen <= 0) | |
338 | status = UREG_BROKEN_PACKET; | |
339 | } | |
340 | } | |
341 | ||
342 | if (status == SUCCESS) | |
343 | { | |
344 | /* Skip over the null */ | |
345 | packet++, pktlen--; | |
346 | ||
347 | if (ureg_validate_char(packet) != SUCCESS) | |
348 | { | |
349 | com_err(whoami, 0, "Packet contains invalid characters."); | |
350 | status = UREG_USER_NOT_FOUND; | |
351 | } | |
352 | else | |
353 | { | |
354 | /* Extract last name from the packet */ | |
355 | message->last = packet; | |
356 | ||
357 | for (; *packet && pktlen > 0; --pktlen, ++packet) | |
358 | continue; | |
359 | if (pktlen <= 0) | |
360 | status = UREG_BROKEN_PACKET; | |
361 | } | |
362 | } | |
363 | ||
364 | if (status == SUCCESS) | |
365 | { | |
366 | packet++, pktlen--; | |
367 | ||
368 | if (pktlen <= 0) | |
369 | status = UREG_BROKEN_PACKET; | |
370 | } | |
371 | ||
372 | /* Extract encrypted information from packet */ | |
373 | message->encrypted = packet; | |
374 | message->encrypted_len = pktlen; | |
375 | ||
376 | if (status == SUCCESS) | |
377 | { | |
378 | com_err(whoami, status, "Request %d for %s %s", message->request, | |
379 | message->first, message->last); | |
380 | } | |
381 | else | |
382 | com_err(whoami, status, " - parse packet failed."); | |
383 | ||
384 | return status; | |
385 | } | |
386 | ||
387 | ||
388 | u_long cur_req_sender(void) | |
389 | { | |
390 | return CUR_REQ.ip_address; | |
391 | } |