1/*
2 * Copyright (c) 2004 Marcel Moolenaar
3 * 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 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/gdb/gdb_packet.c 131899 2004-07-10 17:47:22Z marcel $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/ctype.h>
33#include <sys/kdb.h>
34
35#include <machine/gdb_machdep.h>
36
37#include <gdb/gdb.h>
38#include <gdb/gdb_int.h>
39
40static char gdb_rxbuf[GDB_BUFSZ];
41char *gdb_rxp = NULL;
42size_t gdb_rxsz = 0;
43static char gdb_txbuf[GDB_BUFSZ];
44char *gdb_txp = NULL; /* Used in inline functions. */
45
46#define C2N(c) (((c) < 'A') ? (c) - '0' : \
47 10 + (((c) < 'a') ? (c) - 'A' : (c) - 'a'))
48#define N2C(n) (((n) < 10) ? (n) + '0' : (n) + 'a' - 10)
49
50/*
51 * Functions to receive and extract from a packet.
52 */
53
54int
55gdb_rx_begin(void)
56{
57 int c, cksum;
58
59 gdb_rxp = NULL;
60 do {
61 /*
62 * Wait for the start character, ignore all others.
63 * XXX needs a timeout.
64 */
65 while ((c = gdb_cur->gdb_getc()) != '$')
66 ;
67
68 /* Read until a # or end of buffer is found. */
69 cksum = 0;
70 gdb_rxsz = 0;
71 while (gdb_rxsz < sizeof(gdb_rxbuf) - 1) {
72 c = gdb_cur->gdb_getc();
73 if (c == '#')
74 break;
75 gdb_rxbuf[gdb_rxsz++] = c;
76 cksum += c;
77 }
78 gdb_rxbuf[gdb_rxsz] = 0;
79 cksum &= 0xff;
80
81 /* Bail out on a buffer overflow. */
82 if (c != '#') {
83 gdb_cur->gdb_putc('-');
84 return (ENOSPC);
85 }
86
87 c = gdb_cur->gdb_getc();
88 cksum -= (C2N(c) << 4) & 0xf0;
89 c = gdb_cur->gdb_getc();
90 cksum -= C2N(c) & 0x0f;
91 gdb_cur->gdb_putc((cksum == 0) ? '+' : '-');
92 if (cksum != 0)
93 printf("GDB: packet `%s' has invalid checksum\n",
94 gdb_rxbuf);
95 } while (cksum != 0);
96
97 gdb_rxp = gdb_rxbuf;
98 return (0);
99}
100
101int
102gdb_rx_equal(const char *str)
103{
104 int len;
105
106 len = strlen(str);
107 if (len > gdb_rxsz || strncmp(str, gdb_rxp, len) != 0)
108 return (0);
109 gdb_rxp += len;
110 gdb_rxsz -= len;
111 return (1);
112}
113
114int
115gdb_rx_mem(unsigned char *addr, size_t size)
116{
117 void *prev;
118 jmp_buf jb;
119 int ret;
120 unsigned char c;
121
122 if (size * 2 != gdb_rxsz)
123 return (-1);
124
125 prev = kdb_jmpbuf(jb);
126 ret = setjmp(jb);
127 if (ret == 0) {
128 while (size-- > 0) {
129 c = (C2N(gdb_rxp[0]) << 4) & 0xf0;
130 c |= C2N(gdb_rxp[1]) & 0x0f;
131 *addr++ = c;
132 gdb_rxsz -= 2;
133 gdb_rxp += 2;
134 }
135 }
136 (void)kdb_jmpbuf(prev);
137 return ((ret == 0) ? 1 : 0);
138}
139
140int
141gdb_rx_varhex(uintmax_t *vp)
142{
143 uintmax_t v;
144 int c, neg;
145
146 c = gdb_rx_char();
147 neg = (c == '-') ? 1 : 0;
148 if (neg == 1)
149 c = gdb_rx_char();
150 if (!isxdigit(c)) {
151 gdb_rxp -= ((c == -1) ? 0 : 1) + neg;
152 gdb_rxsz += ((c == -1) ? 0 : 1) + neg;
153 return (-1);
154 }
155 v = 0;
156 do {
157 v <<= 4;
158 v += C2N(c);
159 c = gdb_rx_char();
160 } while (isxdigit(c));
161 if (c != -1) {
162 gdb_rxp--;
163 gdb_rxsz++;
164 }
165 *vp = (neg) ? -v : v;
166 return (0);
167}
168
169/*
170 * Function to build and send a package.
171 */
172
173void
174gdb_tx_begin(char tp)
175{
176
177 gdb_txp = gdb_txbuf;
178 if (tp != '\0')
179 gdb_tx_char(tp);
180}
181
182int
183gdb_tx_end(void)
184{
185 const char *p;
186 int runlen;
187 unsigned char c, cksum;
188
189 do {
190 gdb_cur->gdb_putc('$');
191
192 cksum = 0;
193 p = gdb_txbuf;
194 while (p < gdb_txp) {
195 /* Send a character and start run-length encoding. */
196 c = *p++;
197 gdb_cur->gdb_putc(c);
198 cksum += c;
199 runlen = 0;
200 /* Determine run-length and update checksum. */
201 while (p < gdb_txp && *p == c) {
202 runlen++;
203 p++;
204 }
205 /* Emit the run-length encoded string. */
206 while (runlen >= 97) {
207 gdb_cur->gdb_putc('*');
208 cksum += '*';
209 gdb_cur->gdb_putc(97+29);
210 cksum += 97+29;
211 runlen -= 97;
212 if (runlen > 0) {
213 gdb_cur->gdb_putc(c);
214 cksum += c;
215 runlen--;
216 }
217 }
218 if (runlen == 1) {
219 gdb_cur->gdb_putc(c);
220 cksum += c;
221 runlen--;
222 }
223 if (runlen == 0)
224 continue;
225 /* Don't emit '$', '#', '+' or '-'. */
226 if (runlen == 7) {
227 gdb_cur->gdb_putc(c);
228 cksum += c;
229 runlen--;
230 }
231 if (runlen == 6 || runlen == 14 || runlen == 16) {
232 gdb_cur->gdb_putc(c);
233 cksum += c;
234 runlen--;
235 }
236 gdb_cur->gdb_putc('*');
237 cksum += '*';
238 gdb_cur->gdb_putc(runlen+29);
239 cksum += runlen+29;
240 }
241
242 gdb_cur->gdb_putc('#');
243 c = cksum >> 4;
244 gdb_cur->gdb_putc(N2C(c));
245 c = cksum & 0x0f;
246 gdb_cur->gdb_putc(N2C(c));
247
248 c = gdb_cur->gdb_getc();
249 } while (c != '+');
250
251 return (0);
252}
253
254int
255gdb_tx_mem(const unsigned char *addr, size_t size)
256{
257 void *prev;
258 jmp_buf jb;
259 int ret;
260
261 prev = kdb_jmpbuf(jb);
262 ret = setjmp(jb);
263 if (ret == 0) {
264 while (size-- > 0) {
265 *gdb_txp++ = N2C(*addr >> 4);
266 *gdb_txp++ = N2C(*addr & 0x0f);
267 addr++;
268 }
269 }
270 (void)kdb_jmpbuf(prev);
271 return ((ret == 0) ? 1 : 0);
272}
273
274void
275gdb_tx_reg(int regnum)
276{
277 unsigned char *regp;
278 size_t regsz;
279
280 regp = gdb_cpu_getreg(regnum, &regsz);
281 if (regp == NULL) {
282 /* Register unavailable. */
283 while (regsz--) {
284 gdb_tx_char('x');
285 gdb_tx_char('x');
286 }
287 } else
288 gdb_tx_mem(regp, regsz);
289}