6 * Copyright (C) 1987, 1988 by the Massachusetts Institute of Technology
7 * For copying and distribution information, please see the file
10 * Server for user registration with SMS and Kerberos.
12 * This file handles the processing of requests for the register
17 static char *rcsid_requests_c = "$Header$";
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
25 #include <mit-copyright.h>
29 #include <sys/types.h>
34 #include <sys/socket.h>
35 #include <netinet/in.h>
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)
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) */
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. */
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 */
62 static struct request_save requests[NUM_REQUESTS_SAVED]; /* Saved packets */
63 static int cur_request_index = 0; /* Index to the current request */
66 struct request_save *req;
77 /* Get service information from /etc/services */
78 if ((sp = getservbyname("sms_ureg", "udp")) == NULL)
80 com_err(whoami, errno, " unknown service sms_ureg/udp");
84 /* Get an internet style datagram socket */
85 if ((s = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP)) < 0)
87 com_err(whoami,errno," socket");
90 bzero((char *)&sin,(int)sizeof(sin));
92 sin.sin_family = AF_INET;
93 sin.sin_port = sp->s_port;
94 sin.sin_addr.s_addr = INADDR_ANY;
96 /* Bind a name to the socket */
97 if (bind(s, &sin, sizeof(sin)) < 0)
99 com_err(whoami,errno," bind");
103 for (i = 0; i < NUM_REQUESTS_SAVED; i++)
104 clear_req(&(requests[i]));
107 int handle_retransmitted()
109 register int i; /* A counter */
110 int status = FALSE; /* Return status */
112 for (i = PREV_INDEX(cur_request_index); i != cur_request_index;
115 if ((requests[i].seqno == CUR_REQ.seqno) &&
116 (requests[i].ip_address == sin.sin_addr.s_addr) &&
117 (requests[i].cl_port == sin.sin_port))
118 /* This is a retransmitted packet */
121 com_err(whoami, 0, "Retransmitted packet detected.");
124 (void) sendto(s, requests[i].out_pkt, requests[i].out_pktlen,
133 void respond(status,text)
134 int status; /* Return status for the client */
135 char *text; /* Text for the client */
136 /* This routine takes care of sending packets back to the client and
137 caching the necessary information for retransmission detection.
138 It is the only place in which cur_request_index should be
141 CUR_REQ.out_pktlen = sizeof(CUR_REQ.out_pkt);
143 if (format_pkt(CUR_REQ.out_pkt, &(CUR_REQ.out_pktlen),
144 CUR_REQ.seqno, status, text))
145 com_err(whoami,0,"Client error message was truncated.");
146 (void) sendto(s, CUR_REQ.out_pkt, CUR_REQ.out_pktlen, 0, &sin, addrlen);
148 cur_request_index = NEXT_INDEX(cur_request_index);
151 void get_request(message)
152 struct msg *message; /* Will contain formatted packet information */
154 static char packet[BUFSIZ]; /* Buffer for incoming packet */
155 int pktlen; /* Length of incoming packet */
156 int status = FAILURE; /* Error status */
158 /* Sit around waiting for requests from the client. */
161 com_err(whoami, 0, "*** Ready for next request ***");
162 addrlen = sizeof(sin);
163 /* Receive a packet */
164 if ((pktlen = recvfrom(s,packet,sizeof(packet),0,&sin,&addrlen)) < 0)
166 com_err(whoami, errno, " recvfrom");
167 /* Don't worry if error is interrupted system call. */
168 if (errno == EINTR) continue;
172 /* Store available information */
174 CUR_REQ.ip_address = sin.sin_addr.s_addr;
175 CUR_REQ.cl_port = sin.sin_port;
177 /* Parse a request packet and save sequence number */
178 if ((status = parse_pkt(packet, pktlen, message))
181 /* If error, format packet to send back to the client */
182 respond(status, (char *)NULL);
186 /* Check for retransmitted packet. handle_retransmitted()
187 returns true if it handled a retransmitted packet. */
188 if (!handle_retransmitted())
194 void report(status, message)
198 respond(status, message);
201 int format_pkt(packet, pktlenp, seqno, cl_status, message)
202 char *packet; /* Packet buffer */
203 int *pktlenp; /* Pointer to packet size */
204 U_32BIT seqno; /* Sequence number */
205 int cl_status; /* Error status to return to client */
206 char *message; /* Error message to return to client */
207 /* This routine prepares a packet to send back to the client. A
208 non-zero return status means that the client error message was
211 int len; /* Amount of message to send */
212 int status = SUCCESS; /* Return status */
214 /* Convert byte order to network byte order */
215 U_32BIT vers = htonl((U_32BIT)CUR_UREG_VERSION);
216 cl_status = htonl((U_32BIT)cl_status);
217 /* Put current user registration protocol version into the packet */
218 bcopy((char *)&vers, packet, sizeof(U_32BIT));
219 /* Put sequence number into the packet */
220 bcopy((char *)&seqno, packet+sizeof(U_32BIT), sizeof(U_32BIT));
221 /* Put error status into the packet */
222 bcopy((char *)&cl_status, packet+ 2*sizeof(U_32BIT), sizeof(U_32BIT));
224 /* Find out how much of the message to copy; truncate if too short. */
225 /* How much room is there left? */
226 len = *pktlenp - sizeof(U_32BIT)*3;
227 if (len < strlen(message) + 1) /* Room for null terminator */
229 status = FAILURE; /* Message was truncated */
230 /* Truncate the message */
231 message[len-1] = NULL;
234 /* Copy the message into the packet */
235 (void) strcpy(packet+3*sizeof(U_32BIT), message);
236 *pktlenp = 3*sizeof(U_32BIT) + strlen(message);
241 /* The ureg_validate_char variable and routine were taken verbatim
242 out of server/qsupport.qc where they are called
243 validate_chars. At some point, it may be desirable
244 to put this functionality in one place. */
246 /* ureg_validate_char: verify that there are no illegal characters in
247 * the string. Legal characters are printing chars other than
248 * ", *, ?, \, [ and ].
250 static int illegalchars[] = {
251 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* ^@ - ^O */
252 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* ^P - ^_ */
253 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, /* SPACE - / */
254 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, /* 0 - ? */
255 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* @ - O */
256 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, /* P - _ */
257 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* ` - o */
258 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, /* p - ^? */
259 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
260 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
261 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
262 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
263 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
264 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
265 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
266 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
269 ureg_validate_char(s)
273 if (illegalchars[*s++])
278 parse_pkt(packet, pktlen, message)
282 /* This routine checks a packet and puts the information in it in
283 a structure if it is valid. It also saves the sequence number
284 in the list of saved requests. */
286 int status = SUCCESS; /* Error status */
288 com_err(whoami,0,"Packet received");
290 if (pktlen < sizeof(U_32BIT)) status = UREG_BROKEN_PACKET;
291 if (status == SUCCESS)
293 /* Extract the user registration protocol version from the packet */
294 bcopy(packet, (char *)&message->version, sizeof(long));
295 /* Convert byte order from network to host */
296 message->version = ntohl(message->version);
298 if (message->version != CUR_UREG_VERSION)
299 status = UREG_WRONG_VERSION;
302 if (status == SUCCESS)
304 packet += sizeof(U_32BIT);
305 pktlen -= sizeof(U_32BIT);
307 if (pktlen < sizeof(U_32BIT))
308 status = UREG_BROKEN_PACKET;
311 if (status == SUCCESS)
313 /* Extract the sequence number from the packet */
314 bcopy(packet, (char *)&CUR_REQ.seqno, sizeof(long));
316 packet += sizeof(U_32BIT);
317 pktlen -= sizeof(U_32BIT);
319 if (pktlen < sizeof(U_32BIT))
320 status = UREG_BROKEN_PACKET;
323 if (status == SUCCESS)
325 /* Extract the request from the packet */
326 bcopy(packet, (char *)(&message->request), sizeof(U_32BIT));
327 message->request = ntohl(message->request);
328 packet += sizeof(U_32BIT);
329 pktlen -= sizeof(U_32BIT);
331 /* Make sure that the packet contains only valid characters up
333 if (ureg_validate_char(packet) != SUCCESS)
335 com_err(whoami,0,"Packet contains invalid characters.");
336 status = UREG_USER_NOT_FOUND;
340 /* Extract first name from the packet */
341 message->first = packet;
343 /* Scan forward until null appears in the packet or there
344 is no more packet! */
345 for (; *packet && pktlen > 0; --pktlen, ++packet) continue;
347 status = UREG_BROKEN_PACKET;
351 if (status == SUCCESS)
353 /* Skip over the null */
356 if (ureg_validate_char(packet) != SUCCESS)
358 com_err(whoami,0,"Packet contains invalid characters.");
359 status = UREG_USER_NOT_FOUND;
363 /* Extract last name from the packet */
364 message->last = packet;
366 for (; *packet && pktlen > 0; --pktlen, ++packet) continue;
368 status = UREG_BROKEN_PACKET;
372 if (status == SUCCESS)
377 status = UREG_BROKEN_PACKET;
380 /* Extract encrypted information from packet */
381 message->encrypted = packet;
382 message->encrypted_len = pktlen;
384 if (status == SUCCESS)
387 com_err(whoami,status,"%s\n%s%d\n%s%d\n%s%s\n%s%s",
388 "Packet parsed successfully. Packet contains:",
389 " Protocol version: ",message->version,
390 " Request: ",message->request,
391 " First name: ",message->first,
392 " Last name: ",message->last);
394 com_err(whoami,status,"Request %d for %s %s",message->request,
395 message->first,message->last);
399 com_err(whoami,status," - parse packet failed.");
407 * c-argdecl-indent: 2
409 * c-continued-statement-offset: 4