kdumpd.tproj/kdumpsubs.c

   1 /*
   2  * Copyright (c) 1983, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   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  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 /* Simple minded read-ahead/write-behind subroutines for tftp user and
  31    server.  Written originally with multiple buffers in mind, but current
  32    implementation has two buffer logic wired in.
  33
  34    Todo:  add some sort of final error check so when the write-buffer
  35    is finally flushed, the caller can detect if the disk filled up
  36    (or had an i/o error) and return a nak to the other side.
  37
  38                         Jim Guyton 10/85
  39  */
  40
  41 #ifdef HAVE_CONFIG_H
  42 #include <config.h>
  43 #endif
  44
  45 #include <sys/types.h>
  46 #include <sys/socket.h>
  47 #include <sys/ioctl.h>
  48 #ifdef HAVE_SYS_FILIO_H
  49 #include <sys/filio.h>
  50 #endif
  51 #include <netinet/in.h>
  52 #include "kdump.h"
  53
  54 #include <stdio.h>
  55 #include <unistd.h>
  56
  57 #include "kdumpsubs.h"
  58
  59 #define PKTSIZE SEGSIZE+6       /* should be moved to kdump.h */
  60
  61 struct bf {
  62         int counter;            /* size of data in buffer, or flag */
  63         char buf[PKTSIZE];      /* room for data packet */
  64 } bfs[2];
  65
  66                                 /* Values for bf.counter  */
  67 #define BF_ALLOC -3             /* alloc'd but not yet filled */
  68 #define BF_FREE  -2             /* free */
  69 /* [-1 .. SEGSIZE] = size of data in the data buffer */
  70
  71 static int nextone;             /* index of next buffer to use */
  72 static int current;             /* index of buffer in use */
  73
  74                                 /* control flags for crlf conversions */
  75 int newline = 0;                /* fillbuf: in middle of newline expansion */
  76 int prevchar = -1;              /* putbuf: previous char (cr check) */
  77
  78 static struct kdumphdr *rw_init __P ((int));
  79
  80 struct kdumphdr *w_init() { return rw_init(0); }         /* write-behind */
  81 struct kdumphdr *r_init() { return rw_init(1); }         /* read-ahead */
  82
  83 /* init for either read-ahead or write-behind */
  84 /* zero for write-behind, one for read-head */
  85 static struct kdumphdr *
  86 rw_init(int x)
  87 {
  88         newline = 0;            /* init crlf flag */
  89         prevchar = -1;
  90         bfs[0].counter =  BF_ALLOC;     /* pass out the first buffer */
  91         current = 0;
  92         bfs[1].counter = BF_FREE;
  93         nextone = x;                    /* ahead or behind? */
  94         return (struct kdumphdr *)bfs[0].buf;
  95 }
  96
  97
  98 /* Have emptied current buffer by sending to net and getting ack.
  99    Free it and return next buffer filled with data.
 100  */
 101 /* if true, convert to ascii */
 102 /* file opened for read */
 103
 104 /* int */
 105 /* readit(FILE *file, struct kdumphdr **dpp, int convert) */
 106 /* { */
 107 /*      struct bf *b; */
 108
 109 /*      bfs[current].counter = BF_FREE; /\* free old one *\/ */
 110 /*      current = !current;             /\* "incr" current *\/ */
 111
 112 /*      b = &bfs[current];              /\* look at new buffer *\/ */
 113 /*      if (b->counter == BF_FREE)      /\* if it's empty *\/ */
 114 /*              read_ahead(file, convert);      /\* fill it *\/ */
 115 /* /\*      assert(b->counter != BF_FREE);*\//\* check *\/ */
 116 /*      *dpp = (struct kdumphdr *)b->buf;        /\* set caller's ptr *\/ */
 117 /*      return b->counter; */
 118 /* } */
 119
 120 /*
 121  * fill the input buffer, doing ascii conversions if requested
 122  * conversions are  lf -> cr,lf  and cr -> cr, nul
 123  */
 124 /*      FILE *file;  file opened for read */
 125 /*      int convert;  if true, convert to ascii */
 126 void
 127 read_ahead(FILE *file, int convert)
 128 {
 129         register int i;
 130         register char *p;
 131         register int c;
 132         struct bf *b;
 133         struct kdumphdr *dp;
 134
 135         b = &bfs[nextone];              /* look at "next" buffer */
 136         if (b->counter != BF_FREE)      /* nop if not free */
 137                 return;
 138         nextone = !nextone;             /* "incr" next buffer ptr */
 139
 140         dp = (struct kdumphdr *)b->buf;
 141
 142         if (convert == 0) {
 143                 b->counter = read(fileno(file), dp->th_data, SEGSIZE);
 144                 return;
 145         }
 146
 147         p = dp->th_data;
 148         for (i = 0 ; i < SEGSIZE; i++) {
 149                 if (newline) {
 150                         if (prevchar == '\n')
 151                                 c = '\n';       /* lf to cr,lf */
 152                         else    c = '\0';       /* cr to cr,nul */
 153                         newline = 0;
 154                 }
 155                 else {
 156                         c = getc(file);
 157                         if (c == EOF) break;
 158                         if (c == '\n' || c == '\r') {
 159                                 prevchar = c;
 160                                 c = '\r';
 161                                 newline = 1;
 162                         }
 163                 }
 164                *p++ = c;
 165         }
 166         b->counter = (int)(p - dp->th_data);
 167 }
 168
 169 /* Update count associated with the buffer, get new buffer
 170    from the queue.  Calls write_behind only if next buffer not
 171    available.
 172  */
 173 int
 174 writeit(FILE *file, struct kdumphdr **dpp, int ct, int convert)
 175 {
 176         bfs[current].counter = ct;      /* set size of data to write */
 177         current = !current;             /* switch to other buffer */
 178         if (bfs[current].counter != BF_FREE)     /* if not free */
 179                 (void)write_behind(file, convert); /* flush it */
 180         bfs[current].counter = BF_ALLOC;        /* mark as alloc'd */
 181         *dpp =  (struct kdumphdr *)bfs[current].buf;
 182         return ct;                      /* this is a lie of course */
 183 }
 184
 185 /*
 186  * Output a buffer to a file, converting from netascii if requested.
 187  * CR,NUL -> CR  and CR,LF => LF.
 188  * Note spec is undefined if we get CR as last byte of file or a
 189  * CR followed by anything else.  In this case we leave it alone.
 190  */
 191 int
 192 write_behind(FILE *file, int convert)
 193 {
 194         char *buf;
 195         int count;
 196         register int ct;
 197         register char *p;
 198         register int c;                 /* current character */
 199         struct bf *b;
 200         struct kdumphdr *dp;
 201
 202         b = &bfs[nextone];
 203         if (b->counter < -1)            /* anything to flush? */
 204                 return 0;               /* just nop if nothing to do */
 205
 206         count = b->counter;             /* remember byte count */
 207         b->counter = BF_FREE;           /* reset flag */
 208         dp = (struct kdumphdr *)b->buf;
 209         nextone = !nextone;             /* incr for next time */
 210         buf = dp->th_data;
 211
 212         if (count <= 0) return -1;      /* nak logic? */
 213
 214         if (convert == 0)
 215                 return write(fileno(file), buf, count);
 216
 217         p = buf;
 218         ct = count;
 219         while (ct--) {                  /* loop over the buffer */
 220             c = *p++;                   /* pick up a character */
 221             if (prevchar == '\r') {     /* if prev char was cr */
 222                 if (c == '\n')          /* if have cr,lf then just */
 223                    fseek(file, -1, 1);  /* smash lf on top of the cr */
 224                 else
 225                    if (c == '\0')       /* if have cr,nul then */
 226                         goto skipit;    /* just skip over the putc */
 227                 /* else just fall through and allow it */
 228             }
 229             putc(c, file);
 230 skipit:
 231             prevchar = c;
 232         }
 233         return count;
 234 }
 235
 236
 237 /* When an error has occurred, it is possible that the two sides
 238  * are out of synch.  Ie: that what I think is the other side's
 239  * response to packet N is really their response to packet N-1.
 240  *
 241  * So, to try to prevent that, we flush all the input queued up
 242  * for us on the network connection on our host.
 243  *
 244  * We return the number of packets we flushed (mostly for reporting
 245  * when trace is active).
 246  */
 247
 248 /*int   f;socket to flush */
 249 int
 250 synchnet(int f)
 251 {
 252         int i, j = 0;
 253         char rbuf[PKTSIZE];
 254         struct sockaddr_in from;
 255         int fromlen;
 256
 257         while (1) {
 258                 (void) ioctl(f, FIONREAD, &i);
 259                 if (i) {
 260                         j++;
 261                         fromlen = sizeof from;
 262                         (void) recvfrom(f, rbuf, sizeof (rbuf), 0,
 263                                 (struct sockaddr *)&from, &fromlen);
 264                 } else {
 265                         return(j);
 266                 }
 267         }
 268 }