2 * Copyright (c) 1983, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
39 static const char sccsid[] = "@(#)tftpsubs.c 8.1 (Berkeley) 6/6/93";
42 /* Simple minded read-ahead/write-behind subroutines for tftp user and
43 server. Written originally with multiple buffers in mind, but current
44 implementation has two buffer logic wired in.
46 Todo: add some sort of final error check so when the write-buffer
47 is finally flushed, the caller can detect if the disk filled up
48 (or had an i/o error) and return a nak to the other side.
53 #include <sys/types.h>
54 #include <sys/socket.h>
55 #include <sys/ioctl.h>
56 #include <netinet/in.h>
57 #include <arpa/tftp.h>
64 #define PKTSIZE SEGSIZE+4 /* should be moved to tftp.h */
67 int counter; /* size of data in buffer, or flag */
68 char buf[PKTSIZE]; /* room for data packet */
71 /* Values for bf.counter */
72 #define BF_ALLOC -3 /* alloc'd but not yet filled */
73 #define BF_FREE -2 /* free */
74 /* [-1 .. SEGSIZE] = size of data in the data buffer */
76 static int nextone; /* index of next buffer to use */
77 static int current; /* index of buffer in use */
79 /* control flags for crlf conversions */
80 int newline = 0; /* fillbuf: in middle of newline expansion */
81 int prevchar = -1; /* putbuf: previous char (cr check) */
83 static struct tftphdr *rw_init(int);
85 struct tftphdr *w_init(void) { return rw_init(0); } /* write-behind */
86 struct tftphdr *r_init(void) { return rw_init(1); } /* read-ahead */
88 static struct tftphdr * /* init for either read-ahead or write-behind */
89 rw_init(int x) /* zero for write-behind, one for read-head */
91 newline = 0; /* init crlf flag */
93 bfs[0].counter = BF_ALLOC; /* pass out the first buffer */
95 bfs[1].counter = BF_FREE;
96 nextone = x; /* ahead or behind? */
97 return (struct tftphdr *)bfs[0].buf;
101 /* Have emptied current buffer by sending to net and getting ack.
102 Free it and return next buffer filled with data.
105 readit(FILE *file, /* file opened for read */
106 struct tftphdr **dpp,
107 int convert) /* if true, convert to ascii */
111 bfs[current].counter = BF_FREE; /* free old one */
112 current = !current; /* "incr" current */
114 b = &bfs[current]; /* look at new buffer */
115 if (b->counter == BF_FREE) /* if it's empty */
116 read_ahead(file, convert); /* fill it */
117 /* assert(b->counter != BF_FREE);*//* check */
118 *dpp = (struct tftphdr *)b->buf; /* set caller's ptr */
123 * fill the input buffer, doing ascii conversions if requested
124 * conversions are lf -> cr,lf and cr -> cr, nul
127 read_ahead(FILE *file, /* file opened for read */
128 int convert) /* if true, convert to ascii */
136 b = &bfs[nextone]; /* look at "next" buffer */
137 if (b->counter != BF_FREE) /* nop if not free */
139 nextone = !nextone; /* "incr" next buffer ptr */
141 dp = (struct tftphdr *)b->buf;
144 b->counter = read(fileno(file), dp->th_data, SEGSIZE);
149 for (i = 0 ; i < SEGSIZE; i++) {
151 if (prevchar == '\n')
152 c = '\n'; /* lf to cr,lf */
153 else c = '\0'; /* cr to cr,nul */
159 if (c == '\n' || c == '\r') {
167 b->counter = (int)(p - dp->th_data);
170 /* Update count associated with the buffer, get new buffer
171 from the queue. Calls write_behind only if next buffer not
175 writeit(FILE *file, struct tftphdr **dpp, int ct, int convert)
177 bfs[current].counter = ct; /* set size of data to write */
178 current = !current; /* switch to other buffer */
179 if (bfs[current].counter != BF_FREE) /* if not free */
180 (void)write_behind(file, convert); /* flush it */
181 bfs[current].counter = BF_ALLOC; /* mark as alloc'd */
182 *dpp = (struct tftphdr *)bfs[current].buf;
183 return ct; /* this is a lie of course */
187 * Output a buffer to a file, converting from netascii if requested.
188 * CR,NUL -> CR and CR,LF => LF.
189 * Note spec is undefined if we get CR as last byte of file or a
190 * CR followed by anything else. In this case we leave it alone.
193 write_behind(FILE *file, int convert)
199 register int c; /* current character */
204 if (b->counter < -1) /* anything to flush? */
205 return 0; /* just nop if nothing to do */
207 count = b->counter; /* remember byte count */
208 b->counter = BF_FREE; /* reset flag */
209 dp = (struct tftphdr *)b->buf;
210 nextone = !nextone; /* incr for next time */
213 if (count <= 0) return -1; /* nak logic? */
216 return write(fileno(file), buf, count);
220 while (ct--) { /* loop over the buffer */
221 c = *p++; /* pick up a character */
222 if (prevchar == '\r') { /* if prev char was cr */
223 if (c == '\n') /* if have cr,lf then just */
224 fseek(file, -1, 1); /* smash lf on top of the cr */
226 if (c == '\0') /* if have cr,nul then */
227 goto skipit; /* just skip over the putc */
228 /* else just fall through and allow it */
238 /* When an error has occurred, it is possible that the two sides
239 * are out of synch. Ie: that what I think is the other side's
240 * response to packet N is really their response to packet N-1.
242 * So, to try to prevent that, we flush all the input queued up
243 * for us on the network connection on our host.
245 * We return the number of packets we flushed (mostly for reporting
246 * when trace is active).
250 synchnet(int f) /* socket to flush */
254 struct sockaddr_storage from;
258 (void) ioctl(f, FIONREAD, &i);
261 fromlen = sizeof from;
262 (void) recvfrom(f, rbuf, sizeof (rbuf), 0,
263 (struct sockaddr *)&from, &fromlen);