xmodem.c

   1 /* $OpenBSD: xmodem.c,v 1.5 2013/07/20 19:27:47 naddy Exp $ */
   2
   3 /*
   4  * Copyright (c) 2012 Nicholas Marriott <nicm@openbsd.org>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
  15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
  16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <sys/types.h>
  20
  21 #include <errno.h>
  22 #include <signal.h>
  23 #include <stdio.h>
  24 #include <string.h>
  25 #include <termios.h>
  26 #include <unistd.h>
  27 #include <inttypes.h>
  28
  29 #include "cu.h"
  30
  31 #define XMODEM_BLOCK 128
  32 #define XMODEM_RETRIES 10
  33
  34 #define XMODEM_SOH '\001'
  35 #define XMODEM_EOT '\004'
  36 #define XMODEM_ACK '\006'
  37 #define XMODEM_NAK '\025'
  38 #define XMODEM_SUB '\032'
  39 #define XMODEM_C   '\103'
  40
  41 volatile sig_atomic_t xmodem_stop;
  42
  43 void
  44 xmodem_signal(int sig __attribute__((unused)))
  45 {
  46         xmodem_stop = 1;
  47 }
  48
  49 uint16_t
  50 xmodem_crc16(const u_char *buf, size_t len)
  51 {
  52         uint16_t        crc;
  53         u_int           i, j;
  54
  55         crc = 0;
  56         for (i = 0; i < len; i++) {
  57                 crc = crc ^ *buf++ << 8;
  58                 for (j = 0; j < 8; j++)
  59                         if (crc & 0x8000)
  60                                 crc = crc << 1 ^ 0x1021;
  61                         else
  62                                 crc = crc << 1;
  63         }
  64         return (crc);
  65 }
  66
  67 int
  68 xmodem_read(u_char *c)
  69 {
  70         for (;;) {
  71                 switch (read(line_fd, c, 1)) {
  72                 case -1:
  73                         if (errno == EINTR && !xmodem_stop)
  74                                 continue;
  75                         return (-1);
  76                 case 0:
  77                         errno = EPIPE;
  78                         return (-1);
  79                 case 1:
  80                         return (0);
  81                 }
  82         }
  83 }
  84
  85 int
  86 xmodem_write(const u_char *buf, size_t len)
  87 {
  88         ssize_t n;
  89
  90         while (len > 0) {
  91                 n = write(line_fd, buf, len);
  92                 if (n == -1) {
  93                         if (errno == EINTR && !xmodem_stop)
  94                                 continue;
  95                         return (-1);
  96                 }
  97                 buf += n;
  98                 len -= n;
  99         }
 100         return (0);
 101 }
 102
 103 void
 104 xmodem_send(const char *file)
 105 {
 106         FILE                    *f;
 107         u_char                   buf[3 + XMODEM_BLOCK + 2], c;
 108         size_t                   len, pktlen;
 109         uint8_t                  num;
 110         uint16_t                 crc;
 111         int                      crc_mode;
 112         u_int                    i, total;
 113         struct termios           tio;
 114         struct sigaction         act, oact;
 115
 116         f = fopen(file, "r");
 117         if (f == NULL) {
 118                 cu_warn("%s", file);
 119                 return;
 120         }
 121
 122         memset(&act, 0, sizeof(act));
 123         sigemptyset(&act.sa_mask);
 124         act.sa_flags = 0;
 125         act.sa_handler = xmodem_signal;
 126         if (sigaction(SIGINT, &act, &oact) != 0)
 127                 cu_err(1, "sigaction");
 128         xmodem_stop = 0;
 129
 130         if (isatty(STDIN_FILENO)) {
 131                 memcpy(&tio, &saved_tio, sizeof(tio));
 132                 tio.c_lflag &= ~ECHO;
 133                 if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &tio) != 0)
 134                         cu_err(1, "tcsetattr");
 135         }
 136
 137         tcflush(line_fd, TCIFLUSH);
 138         if (xmodem_read(&c) != 0)
 139                 goto fail;
 140         if (c == XMODEM_C)
 141                 crc_mode = 1;
 142         else if (c == XMODEM_NAK)
 143                 crc_mode = 0;
 144         else {
 145                 cu_warnx("%s: unexpected response \%03hho", file, c);
 146                 goto fail;
 147         }
 148
 149         num = 1;
 150         total = 1;
 151         pktlen = 3 + XMODEM_BLOCK + (crc_mode ? 2 : 1);
 152         for (;;) {
 153                 len = fread(buf + 3, 1, XMODEM_BLOCK, f);
 154                 if (len == 0)
 155                         break;
 156                 memset(buf + 3 + len, XMODEM_SUB, XMODEM_BLOCK - len);
 157
 158                 buf[0] = XMODEM_SOH;
 159                 buf[1] = num;
 160                 buf[2] = 255 - num;
 161
 162                 if (crc_mode) {
 163                         crc = xmodem_crc16(buf + 3, XMODEM_BLOCK);
 164                         buf[3 + XMODEM_BLOCK] = crc >> 8;
 165                         buf[3 + XMODEM_BLOCK + 1] = crc & 0xFF;
 166                 } else {
 167                         buf[3 + XMODEM_BLOCK] = 0;
 168                         for (i = 0; i < XMODEM_BLOCK; i++)
 169                                 buf[3 + XMODEM_BLOCK] += buf[3 + i];
 170                 }
 171
 172                 for (i = 0; i < XMODEM_RETRIES; i++) {
 173                         if (xmodem_stop) {
 174                                 errno = EINTR;
 175                                 goto fail;
 176                         }
 177                         cu_warnx("%s: sending block %u (attempt %u)", file,
 178                             total, 1 + i);
 179                         if (xmodem_write(buf, pktlen) != 0)
 180                                 goto fail;
 181
 182                         if (xmodem_read(&c) != 0)
 183                                 goto fail;
 184                         if (c == XMODEM_ACK)
 185                                 break;
 186                         if (c != XMODEM_NAK) {
 187                                 cu_warnx("%s: unexpected response \%03hho",
 188                                     file, c);
 189                         }
 190                 }
 191                 if (i == XMODEM_RETRIES) {
 192                         cu_warnx("%s: too many retries", file);
 193                         goto out;
 194                 }
 195
 196                 if (len < XMODEM_BLOCK)
 197                         break;
 198                 num++;
 199                 total++;
 200         }
 201
 202         buf[0] = XMODEM_EOT;
 203         if (xmodem_write(buf, 1) != 0)
 204                 goto fail;
 205         cu_warnx("%s: completed %u blocks", file, num);
 206
 207         goto out;
 208
 209 fail:
 210         cu_warn("%s", file);
 211
 212 out:
 213         set_termios();
 214
 215         sigaction(SIGINT, &oact, NULL);
 216
 217         fclose(f);
 218 }