| 1 | /* |
| 2 | * ldisc.c: PuTTY line discipline. Sits between the input coming |
| 3 | * from keypresses in the window, and the output channel leading to |
| 4 | * the back end. Implements echo and/or local line editing, |
| 5 | * depending on what's currently configured. |
| 6 | */ |
| 7 | |
| 8 | #include <windows.h> |
| 9 | #include <stdio.h> |
| 10 | #include <ctype.h> |
| 11 | |
| 12 | #include "putty.h" |
| 13 | |
| 14 | #define ECHOING (cfg.localecho == LD_YES || \ |
| 15 | (cfg.localecho == LD_BACKEND && \ |
| 16 | (back->ldisc(LD_ECHO) || term_ldisc(LD_ECHO)))) |
| 17 | #define EDITING (cfg.localedit == LD_YES || \ |
| 18 | (cfg.localedit == LD_BACKEND && \ |
| 19 | (back->ldisc(LD_EDIT) || term_ldisc(LD_EDIT)))) |
| 20 | |
| 21 | static void c_write(char *buf, int len) |
| 22 | { |
| 23 | from_backend(0, buf, len); |
| 24 | } |
| 25 | |
| 26 | static char *term_buf = NULL; |
| 27 | static int term_buflen = 0, term_bufsiz = 0, term_quotenext = 0; |
| 28 | |
| 29 | static int plen(unsigned char c) |
| 30 | { |
| 31 | if ((c >= 32 && c <= 126) || (c >= 160 && !in_utf)) |
| 32 | return 1; |
| 33 | else if (c < 128) |
| 34 | return 2; /* ^x for some x */ |
| 35 | else |
| 36 | return 4; /* <XY> for hex XY */ |
| 37 | } |
| 38 | |
| 39 | static void pwrite(unsigned char c) |
| 40 | { |
| 41 | if ((c >= 32 && c <= 126) || (c >= 160 && !in_utf)) { |
| 42 | c_write(&c, 1); |
| 43 | } else if (c < 128) { |
| 44 | char cc[2]; |
| 45 | cc[1] = (c == 127 ? '?' : c + 0x40); |
| 46 | cc[0] = '^'; |
| 47 | c_write(cc, 2); |
| 48 | } else { |
| 49 | char cc[5]; |
| 50 | sprintf(cc, "<%02X>", c); |
| 51 | c_write(cc, 4); |
| 52 | } |
| 53 | } |
| 54 | |
| 55 | static void bsb(int n) |
| 56 | { |
| 57 | while (n--) |
| 58 | c_write("\010 \010", 3); |
| 59 | } |
| 60 | |
| 61 | #define CTRL(x) (x^'@') |
| 62 | #define KCTRL(x) ((x^'@') | 0x100) |
| 63 | |
| 64 | void ldisc_send(char *buf, int len) |
| 65 | { |
| 66 | int keyflag = 0; |
| 67 | /* |
| 68 | * Called with len=0 when the options change. We must inform |
| 69 | * the front end in case it needs to know. |
| 70 | */ |
| 71 | if (len == 0) { |
| 72 | void ldisc_update(int echo, int edit); |
| 73 | ldisc_update(ECHOING, EDITING); |
| 74 | } |
| 75 | /* |
| 76 | * Less than zero means null terminated special string. |
| 77 | */ |
| 78 | if (len < 0) { |
| 79 | len = strlen(buf); |
| 80 | keyflag = KCTRL('@'); |
| 81 | } |
| 82 | /* |
| 83 | * Either perform local editing, or just send characters. |
| 84 | */ |
| 85 | if (EDITING) { |
| 86 | while (len--) { |
| 87 | int c; |
| 88 | c = *buf++ + keyflag; |
| 89 | switch (term_quotenext ? ' ' : c) { |
| 90 | /* |
| 91 | * ^h/^?: delete one char and output one BSB |
| 92 | * ^w: delete, and output BSBs, to return to last |
| 93 | * space/nonspace boundary |
| 94 | * ^u: delete, and output BSBs, to return to BOL |
| 95 | * ^c: Do a ^u then send a telnet IP |
| 96 | * ^z: Do a ^u then send a telnet SUSP |
| 97 | * ^\: Do a ^u then send a telnet ABORT |
| 98 | * ^r: echo "^R\n" and redraw line |
| 99 | * ^v: quote next char |
| 100 | * ^d: if at BOL, end of file and close connection, |
| 101 | * else send line and reset to BOL |
| 102 | * ^m: send line-plus-\r\n and reset to BOL |
| 103 | */ |
| 104 | case KCTRL('H'): |
| 105 | case KCTRL('?'): /* backspace/delete */ |
| 106 | if (term_buflen > 0) { |
| 107 | if (ECHOING) |
| 108 | bsb(plen(term_buf[term_buflen - 1])); |
| 109 | term_buflen--; |
| 110 | } |
| 111 | break; |
| 112 | case CTRL('W'): /* delete word */ |
| 113 | while (term_buflen > 0) { |
| 114 | if (ECHOING) |
| 115 | bsb(plen(term_buf[term_buflen - 1])); |
| 116 | term_buflen--; |
| 117 | if (term_buflen > 0 && |
| 118 | isspace(term_buf[term_buflen - 1]) && |
| 119 | !isspace(term_buf[term_buflen])) |
| 120 | break; |
| 121 | } |
| 122 | break; |
| 123 | case CTRL('U'): /* delete line */ |
| 124 | case CTRL('C'): /* Send IP */ |
| 125 | case CTRL('\\'): /* Quit */ |
| 126 | case CTRL('Z'): /* Suspend */ |
| 127 | while (term_buflen > 0) { |
| 128 | if (ECHOING) |
| 129 | bsb(plen(term_buf[term_buflen - 1])); |
| 130 | term_buflen--; |
| 131 | } |
| 132 | back->special(TS_EL); |
| 133 | if (c == CTRL('C')) |
| 134 | back->special(TS_IP); |
| 135 | if (c == CTRL('Z')) |
| 136 | back->special(TS_SUSP); |
| 137 | if (c == CTRL('\\')) |
| 138 | back->special(TS_ABORT); |
| 139 | break; |
| 140 | case CTRL('R'): /* redraw line */ |
| 141 | if (ECHOING) { |
| 142 | int i; |
| 143 | c_write("^R\r\n", 4); |
| 144 | for (i = 0; i < term_buflen; i++) |
| 145 | pwrite(term_buf[i]); |
| 146 | } |
| 147 | break; |
| 148 | case CTRL('V'): /* quote next char */ |
| 149 | term_quotenext = TRUE; |
| 150 | break; |
| 151 | case CTRL('D'): /* logout or send */ |
| 152 | if (term_buflen == 0) { |
| 153 | back->special(TS_EOF); |
| 154 | } else { |
| 155 | back->send(term_buf, term_buflen); |
| 156 | term_buflen = 0; |
| 157 | } |
| 158 | break; |
| 159 | /* |
| 160 | * This particularly hideous bit of code from RDB |
| 161 | * allows ordinary ^M^J to do the same thing as |
| 162 | * magic-^M when in Raw protocol. The line `case |
| 163 | * KCTRL('M'):' is _inside_ the if block. Thus: |
| 164 | * |
| 165 | * - receiving regular ^M goes straight to the |
| 166 | * default clause and inserts as a literal ^M. |
| 167 | * - receiving regular ^J _not_ directly after a |
| 168 | * literal ^M (or not in Raw protocol) fails the |
| 169 | * if condition, leaps to the bottom of the if, |
| 170 | * and falls through into the default clause |
| 171 | * again. |
| 172 | * - receiving regular ^J just after a literal ^M |
| 173 | * in Raw protocol passes the if condition, |
| 174 | * deletes the literal ^M, and falls through |
| 175 | * into the magic-^M code |
| 176 | * - receiving a magic-^M empties the line buffer, |
| 177 | * signals end-of-line in one of the various |
| 178 | * entertaining ways, and _doesn't_ fall out of |
| 179 | * the bottom of the if and through to the |
| 180 | * default clause because of the break. |
| 181 | */ |
| 182 | case CTRL('J'): |
| 183 | if (cfg.protocol == PROT_RAW && |
| 184 | term_buflen > 0 && term_buf[term_buflen - 1] == '\r') { |
| 185 | if (ECHOING) |
| 186 | bsb(plen(term_buf[term_buflen - 1])); |
| 187 | term_buflen--; |
| 188 | /* FALLTHROUGH */ |
| 189 | case KCTRL('M'): /* send with newline */ |
| 190 | if (term_buflen > 0) |
| 191 | back->send(term_buf, term_buflen); |
| 192 | if (cfg.protocol == PROT_RAW) |
| 193 | back->send("\r\n", 2); |
| 194 | else if (cfg.protocol == PROT_TELNET) |
| 195 | back->special(TS_EOL); |
| 196 | else |
| 197 | back->send("\r", 1); |
| 198 | if (ECHOING) |
| 199 | c_write("\r\n", 2); |
| 200 | term_buflen = 0; |
| 201 | break; |
| 202 | } |
| 203 | /* FALLTHROUGH */ |
| 204 | default: /* get to this label from ^V handler */ |
| 205 | if (term_buflen >= term_bufsiz) { |
| 206 | term_bufsiz = term_buflen + 256; |
| 207 | term_buf = saferealloc(term_buf, term_bufsiz); |
| 208 | } |
| 209 | term_buf[term_buflen++] = c; |
| 210 | if (ECHOING) |
| 211 | pwrite((unsigned char) c); |
| 212 | term_quotenext = FALSE; |
| 213 | break; |
| 214 | } |
| 215 | } |
| 216 | } else { |
| 217 | if (term_buflen != 0) { |
| 218 | back->send(term_buf, term_buflen); |
| 219 | while (term_buflen > 0) { |
| 220 | bsb(plen(term_buf[term_buflen - 1])); |
| 221 | term_buflen--; |
| 222 | } |
| 223 | } |
| 224 | if (len > 0) { |
| 225 | if (ECHOING) |
| 226 | c_write(buf, len); |
| 227 | if (keyflag && cfg.protocol == PROT_TELNET && len == 1) { |
| 228 | switch (buf[0]) { |
| 229 | case CTRL('M'): |
| 230 | back->special(TS_EOL); |
| 231 | break; |
| 232 | case CTRL('?'): |
| 233 | case CTRL('H'): |
| 234 | if (cfg.telnet_keyboard) { |
| 235 | back->special(TS_EC); |
| 236 | break; |
| 237 | } |
| 238 | case CTRL('C'): |
| 239 | if (cfg.telnet_keyboard) { |
| 240 | back->special(TS_IP); |
| 241 | break; |
| 242 | } |
| 243 | case CTRL('Z'): |
| 244 | if (cfg.telnet_keyboard) { |
| 245 | back->special(TS_SUSP); |
| 246 | break; |
| 247 | } |
| 248 | |
| 249 | default: |
| 250 | back->send(buf, len); |
| 251 | break; |
| 252 | } |
| 253 | } else |
| 254 | back->send(buf, len); |
| 255 | } |
| 256 | } |
| 257 | } |