| /* |
| * Copyright (c) 1983 Regents of the University of California. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. All advertising materials mentioning features or use of this software |
| * must display the following acknowledgement: |
| * This product includes software developed by the University of |
| * California, Berkeley and its contributors. |
| * 4. Neither the name of the University nor the names of its contributors |
| * may be used to endorse or promote products derived from this software |
| * without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| #ifndef lint |
| /*static char sccsid[] = "from: @(#)tftpsubs.c 5.6 (Berkeley) 2/28/91";*/ |
| /* static char rcsid[] = "$Id: tftpsubs.c,v 1.2 1993/08/01 18:07:04 mycroft Exp $"; */ |
| #endif /* not lint */ |
| |
| /* Simple minded read-ahead/write-behind subroutines for tftp user and |
| server. Written originally with multiple buffers in mind, but current |
| implementation has two buffer logic wired in. |
| |
| Todo: add some sort of final error check so when the write-buffer |
| is finally flushed, the caller can detect if the disk filled up |
| (or had an i/o error) and return a nak to the other side. |
| |
| Jim Guyton 10/85 |
| */ |
| |
| #include <sys/types.h> |
| #include <sys/socket.h> |
| #include <sys/ioctl.h> |
| #include <netinet/in.h> |
| #include <unistd.h> |
| #include <stdio.h> |
| |
| #include "tftp.h" |
| |
| #define PKTSIZE SEGSIZE+4 /* should be moved to tftp.h */ |
| |
| struct bf { |
| int counter; /* size of data in buffer, or flag */ |
| char buf[PKTSIZE]; /* room for data packet */ |
| } bfs[2]; |
| |
| /* Values for bf.counter */ |
| #define BF_ALLOC -3 /* alloc'd but not yet filled */ |
| #define BF_FREE -2 /* free */ |
| /* [-1 .. SEGSIZE] = size of data in the data buffer */ |
| |
| static int nextone; /* index of next buffer to use */ |
| static int current; /* index of buffer in use */ |
| |
| /* control flags for crlf conversions */ |
| int newline = 0; /* fillbuf: in middle of newline expansion */ |
| int prevchar = -1; /* putbuf: previous char (cr check) */ |
| |
| struct tftphdr *rw_init(int); |
| |
| struct tftphdr *w_init() { return rw_init(0); } /* write-behind */ |
| struct tftphdr *r_init() { return rw_init(1); } /* read-ahead */ |
| |
| /* init for either read-ahead or write-behind */ |
| /* x is zero for write-behind, one for read-head */ |
| struct tftphdr *rw_init(int x) |
| { |
| newline = 0; /* init crlf flag */ |
| prevchar = -1; |
| bfs[0].counter = BF_ALLOC; /* pass out the first buffer */ |
| current = 0; |
| bfs[1].counter = BF_FREE; |
| nextone = x; /* ahead or behind? */ |
| return (struct tftphdr *)bfs[0].buf; |
| } |
| |
| |
| /* Have emptied current buffer by sending to net and getting ack. |
| Free it and return next buffer filled with data. |
| */ |
| int readit(FILE * file, struct tftphdr **dpp, int convert) |
| { |
| struct bf *b; |
| |
| bfs[current].counter = BF_FREE; /* free old one */ |
| current = !current; /* "incr" current */ |
| |
| b = &bfs[current]; /* look at new buffer */ |
| if (b->counter == BF_FREE) /* if it's empty */ |
| read_ahead(file, convert); /* fill it */ |
| #if 0 |
| assert(b->counter != BF_FREE); /* check */ |
| #endif |
| *dpp = (struct tftphdr *)b->buf; /* set caller's ptr */ |
| return b->counter; |
| } |
| |
| /* |
| * fill the input buffer, doing ascii conversions if requested |
| * conversions are lf -> cr,lf and cr -> cr, nul |
| */ |
| void read_ahead(FILE *file, int convert) |
| { |
| register int i; |
| register char *p; |
| register int c; |
| struct bf *b; |
| struct tftphdr *dp; |
| |
| b = &bfs[nextone]; /* look at "next" buffer */ |
| if (b->counter != BF_FREE) /* nop if not free */ |
| return; |
| nextone = !nextone; /* "incr" next buffer ptr */ |
| |
| dp = (struct tftphdr *)b->buf; |
| |
| if (convert == 0) { |
| b->counter = read(fileno(file), dp->th_data, SEGSIZE); |
| return; |
| } |
| |
| p = dp->th_data; |
| for (i = 0 ; i < SEGSIZE; i++) { |
| if (newline) { |
| if (prevchar == '\n') |
| c = '\n'; /* lf to cr,lf */ |
| else c = '\0'; /* cr to cr,nul */ |
| newline = 0; |
| } |
| else { |
| c = getc(file); |
| if (c == EOF) break; |
| if (c == '\n' || c == '\r') { |
| prevchar = c; |
| c = '\r'; |
| newline = 1; |
| } |
| } |
| *p++ = c; |
| } |
| b->counter = (int)(p - dp->th_data); |
| } |
| |
| /* Update count associated with the buffer, get new buffer |
| from the queue. Calls write_behind only if next buffer not |
| available. |
| */ |
| int writeit(FILE *file, struct tftphdr **dpp, int ct, int convert) |
| { |
| bfs[current].counter = ct; /* set size of data to write */ |
| current = !current; /* switch to other buffer */ |
| if (bfs[current].counter != BF_FREE) /* if not free */ |
| write_behind(file, convert); /* flush it */ |
| bfs[current].counter = BF_ALLOC; /* mark as alloc'd */ |
| *dpp = (struct tftphdr *)bfs[current].buf; |
| return ct; /* this is a lie of course */ |
| } |
| |
| /* |
| * Output a buffer to a file, converting from netascii if requested. |
| * CR,NUL -> CR and CR,LF => LF. |
| * Note spec is undefined if we get CR as last byte of file or a |
| * CR followed by anything else. In this case we leave it alone. |
| */ |
| int write_behind(FILE *file, int convert) |
| { |
| char *buf; |
| int count; |
| register int ct; |
| register char *p; |
| register int c; /* current character */ |
| struct bf *b; |
| struct tftphdr *dp; |
| |
| b = &bfs[nextone]; |
| if (b->counter < -1) /* anything to flush? */ |
| return 0; /* just nop if nothing to do */ |
| |
| count = b->counter; /* remember byte count */ |
| b->counter = BF_FREE; /* reset flag */ |
| dp = (struct tftphdr *)b->buf; |
| nextone = !nextone; /* incr for next time */ |
| buf = dp->th_data; |
| |
| if (count <= 0) return -1; /* nak logic? */ |
| |
| if (convert == 0) |
| return write(fileno(file), buf, count); |
| |
| p = buf; |
| ct = count; |
| while (ct--) { /* loop over the buffer */ |
| c = *p++; /* pick up a character */ |
| if (prevchar == '\r') { /* if prev char was cr */ |
| if (c == '\n') /* if have cr,lf then just */ |
| fseek(file, -1, 1); /* smash lf on top of the cr */ |
| else |
| if (c == '\0') /* if have cr,nul then */ |
| goto skipit; /* just skip over the putc */ |
| /* else just fall through and allow it */ |
| } |
| putc(c, file); |
| skipit: |
| prevchar = c; |
| } |
| return count; |
| } |
| |
| |
| /* When an error has occurred, it is possible that the two sides |
| * are out of synch. Ie: that what I think is the other side's |
| * response to packet N is really their response to packet N-1. |
| * |
| * So, to try to prevent that, we flush all the input queued up |
| * for us on the network connection on our host. |
| * |
| * We return the number of packets we flushed (mostly for reporting |
| * when trace is active). |
| */ |
| |
| int synchnet(int f) |
| { |
| int j = 0; |
| char dummy; |
| |
| while (1) { |
| if (recv(f, &dummy, 1, MSG_DONTWAIT) < 0) |
| break; |
| j++; |
| } |
| return j; |
| } |