1 f024663d 2021-09-05 stsp /*
  2 f024663d 2021-09-05 stsp  * Copyright (c) 2019 Ori Bernstein <ori@openbsd.org>
  3 f024663d 2021-09-05 stsp  * Copyright (c) 2021 Stefan Sperling <stsp@openbsd.org>
  4 f024663d 2021-09-05 stsp  *
  5 f024663d 2021-09-05 stsp  * Permission to use, copy, modify, and distribute this software for any
  6 f024663d 2021-09-05 stsp  * purpose with or without fee is hereby granted, provided that the above
  7 f024663d 2021-09-05 stsp  * copyright notice and this permission notice appear in all copies.
  8 f024663d 2021-09-05 stsp  *
  9 f024663d 2021-09-05 stsp  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 10 f024663d 2021-09-05 stsp  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 11 f024663d 2021-09-05 stsp  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 12 f024663d 2021-09-05 stsp  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 13 f024663d 2021-09-05 stsp  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 14 f024663d 2021-09-05 stsp  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 15 f024663d 2021-09-05 stsp  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 16 f024663d 2021-09-05 stsp  */
 17 f024663d 2021-09-05 stsp 
 18 f024663d 2021-09-05 stsp #include <ctype.h>
 19 f024663d 2021-09-05 stsp #include <errno.h>
 20 f024663d 2021-09-05 stsp #include <limits.h>
 21 f024663d 2021-09-05 stsp #include <stdio.h>
 22 f024663d 2021-09-05 stsp #include <stdlib.h>
 23 f024663d 2021-09-05 stsp #include <unistd.h>
 24 f024663d 2021-09-05 stsp 
 25 f024663d 2021-09-05 stsp #include "got_error.h"
 26 ef20f542 2022-06-26 thomas #include "got_lib_pkt.h"
 27 f024663d 2021-09-05 stsp 
 28 f024663d 2021-09-05 stsp const struct got_error *
 29 f024663d 2021-09-05 stsp got_pkt_readn(ssize_t *off, int fd, void *buf, size_t n)
 30 f024663d 2021-09-05 stsp {
 31 f024663d 2021-09-05 stsp 	ssize_t r;
 32 f024663d 2021-09-05 stsp 
 33 f024663d 2021-09-05 stsp 	*off = 0;
 34 f024663d 2021-09-05 stsp 	while (*off != n) {
 35 f024663d 2021-09-05 stsp 		r = read(fd, buf + *off, n - *off);
 36 f024663d 2021-09-05 stsp 		if (r == -1)
 37 f024663d 2021-09-05 stsp 			return got_error_from_errno("read");
 38 f024663d 2021-09-05 stsp 		if (r == 0)
 39 23ac5000 2023-01-23 thomas 			return got_error(GOT_ERR_EOF);
 40 f024663d 2021-09-05 stsp 		*off += r;
 41 f024663d 2021-09-05 stsp 	}
 42 f024663d 2021-09-05 stsp 	return NULL;
 43 f024663d 2021-09-05 stsp }
 44 f024663d 2021-09-05 stsp 
 45 f024663d 2021-09-05 stsp const struct got_error *
 46 f024663d 2021-09-05 stsp got_pkt_flushpkt(int fd, int chattygot)
 47 f024663d 2021-09-05 stsp {
 48 f024663d 2021-09-05 stsp 	ssize_t w;
 49 f024663d 2021-09-05 stsp 
 50 f024663d 2021-09-05 stsp 	if (chattygot > 1)
 51 f024663d 2021-09-05 stsp 		fprintf(stderr, "%s: writepkt: 0000\n", getprogname());
 52 f024663d 2021-09-05 stsp 
 53 f024663d 2021-09-05 stsp 	w = write(fd, "0000", 4);
 54 f024663d 2021-09-05 stsp 	if (w == -1)
 55 f024663d 2021-09-05 stsp 		return got_error_from_errno("write");
 56 f024663d 2021-09-05 stsp 	if (w != 4)
 57 f024663d 2021-09-05 stsp 		return got_error(GOT_ERR_IO);
 58 f024663d 2021-09-05 stsp 	return NULL;
 59 f024663d 2021-09-05 stsp }
 60 f024663d 2021-09-05 stsp 
 61 564cf664 2024-04-25 thomas.ad const struct got_error *
 62 564cf664 2024-04-25 thomas.ad got_pkt_readlen(int *len, const char *str, int chattygot)
 63 564cf664 2024-04-25 thomas.ad {
 64 564cf664 2024-04-25 thomas.ad 	int	 i;
 65 564cf664 2024-04-25 thomas.ad 
 66 564cf664 2024-04-25 thomas.ad 	*len = 0;
 67 564cf664 2024-04-25 thomas.ad 	for (i = 0; i < 4; i++) {
 68 564cf664 2024-04-25 thomas.ad 		if ('0' <= str[i] && str[i] <= '9') {
 69 564cf664 2024-04-25 thomas.ad 			*len *= 16;
 70 564cf664 2024-04-25 thomas.ad 			*len += str[i] - '0';
 71 564cf664 2024-04-25 thomas.ad 		} else if ('a' <= str[i] && str[i] <= 'f') {
 72 564cf664 2024-04-25 thomas.ad 			*len *= 16;
 73 564cf664 2024-04-25 thomas.ad 			*len += str[i] - 'a' + 10;
 74 564cf664 2024-04-25 thomas.ad 		} else {
 75 564cf664 2024-04-25 thomas.ad 			if (chattygot)
 76 564cf664 2024-04-25 thomas.ad 				fprintf(stderr, "%s: bad length: '.4%s'\n",
 77 564cf664 2024-04-25 thomas.ad 				    getprogname(), str);
 78 564cf664 2024-04-25 thomas.ad 			return got_error_msg(GOT_ERR_BAD_PACKET,
 79 564cf664 2024-04-25 thomas.ad 			    "packet length has invalid format");
 80 564cf664 2024-04-25 thomas.ad 		}
 81 564cf664 2024-04-25 thomas.ad 	}
 82 564cf664 2024-04-25 thomas.ad 	return NULL;
 83 564cf664 2024-04-25 thomas.ad }
 84 564cf664 2024-04-25 thomas.ad 
 85 f024663d 2021-09-05 stsp /*
 86 f024663d 2021-09-05 stsp  * Packet header contains a 4-byte hexstring which specifies the length
 87 f024663d 2021-09-05 stsp  * of data which follows.
 88 f024663d 2021-09-05 stsp  */
 89 f024663d 2021-09-05 stsp const struct got_error *
 90 f024663d 2021-09-05 stsp got_pkt_readhdr(int *datalen, int fd, int chattygot)
 91 f024663d 2021-09-05 stsp {
 92 564cf664 2024-04-25 thomas.ad 	static const struct got_error *err;
 93 564cf664 2024-04-25 thomas.ad 	char lenstr[4];
 94 f024663d 2021-09-05 stsp 	ssize_t r;
 95 564cf664 2024-04-25 thomas.ad 	int n;
 96 f024663d 2021-09-05 stsp 
 97 f024663d 2021-09-05 stsp 	*datalen = 0;
 98 f024663d 2021-09-05 stsp 
 99 f024663d 2021-09-05 stsp 	err = got_pkt_readn(&r, fd, lenstr, 4);
100 f024663d 2021-09-05 stsp 	if (err)
101 f024663d 2021-09-05 stsp 		return err;
102 f024663d 2021-09-05 stsp 	if (r == 0) {
103 f024663d 2021-09-05 stsp 		/* implicit "0000" */
104 f024663d 2021-09-05 stsp 		if (chattygot > 1)
105 f024663d 2021-09-05 stsp 			fprintf(stderr, "%s: readpkt: 0000\n", getprogname());
106 f024663d 2021-09-05 stsp 		return NULL;
107 f024663d 2021-09-05 stsp 	}
108 f024663d 2021-09-05 stsp 	if (r != 4)
109 f024663d 2021-09-05 stsp 		return got_error_msg(GOT_ERR_BAD_PACKET,
110 f024663d 2021-09-05 stsp 		    "wrong packet header length");
111 f024663d 2021-09-05 stsp 
112 564cf664 2024-04-25 thomas.ad 	err = got_pkt_readlen(&n, lenstr, chattygot);
113 f024663d 2021-09-05 stsp 	if (n == 0)
114 564cf664 2024-04-25 thomas.ad 		return err;
115 f024663d 2021-09-05 stsp 	if (n <= 4)
116 f024663d 2021-09-05 stsp 		return got_error_msg(GOT_ERR_BAD_PACKET, "packet too short");
117 564cf664 2024-04-25 thomas.ad 	n -= 4;
118 f024663d 2021-09-05 stsp 
119 f024663d 2021-09-05 stsp 	*datalen = n;
120 f024663d 2021-09-05 stsp 	return NULL;
121 f024663d 2021-09-05 stsp }
122 f024663d 2021-09-05 stsp 
123 f024663d 2021-09-05 stsp const struct got_error *
124 f024663d 2021-09-05 stsp got_pkt_readpkt(int *outlen, int fd, char *buf, int buflen, int chattygot)
125 f024663d 2021-09-05 stsp {
126 f024663d 2021-09-05 stsp 	const struct got_error *err = NULL;
127 f024663d 2021-09-05 stsp 	int datalen, i;
128 f024663d 2021-09-05 stsp 	ssize_t n;
129 f024663d 2021-09-05 stsp 
130 f024663d 2021-09-05 stsp 	err = got_pkt_readhdr(&datalen, fd, chattygot);
131 f024663d 2021-09-05 stsp 	if (err)
132 f024663d 2021-09-05 stsp 		return err;
133 f024663d 2021-09-05 stsp 
134 f024663d 2021-09-05 stsp 	if (datalen > buflen)
135 f024663d 2021-09-05 stsp 		return got_error(GOT_ERR_NO_SPACE);
136 f024663d 2021-09-05 stsp 
137 f024663d 2021-09-05 stsp 	err = got_pkt_readn(&n, fd, buf, datalen);
138 f024663d 2021-09-05 stsp 	if (err)
139 f024663d 2021-09-05 stsp 		return err;
140 f024663d 2021-09-05 stsp 	if (n != datalen)
141 f024663d 2021-09-05 stsp 		return got_error_msg(GOT_ERR_BAD_PACKET, "short packet");
142 f024663d 2021-09-05 stsp 
143 f024663d 2021-09-05 stsp 	if (chattygot > 1) {
144 f024663d 2021-09-05 stsp 		fprintf(stderr, "%s: readpkt: %zd:\t", getprogname(), n);
145 f024663d 2021-09-05 stsp 		for (i = 0; i < n; i++) {
146 6771d425 2022-11-17 thomas 			if (isprint((unsigned char)buf[i]))
147 f024663d 2021-09-05 stsp 				fputc(buf[i], stderr);
148 f024663d 2021-09-05 stsp 			else
149 f024663d 2021-09-05 stsp 				fprintf(stderr, "[0x%.2x]", buf[i]);
150 f024663d 2021-09-05 stsp 		}
151 f024663d 2021-09-05 stsp 		fputc('\n', stderr);
152 f024663d 2021-09-05 stsp 	}
153 f024663d 2021-09-05 stsp 
154 f024663d 2021-09-05 stsp 	*outlen = n;
155 f024663d 2021-09-05 stsp 	return NULL;
156 f024663d 2021-09-05 stsp }
157 f024663d 2021-09-05 stsp 
158 f024663d 2021-09-05 stsp const struct got_error *
159 f024663d 2021-09-05 stsp got_pkt_writepkt(int fd, char *buf, int nbuf, int chattygot)
160 f024663d 2021-09-05 stsp {
161 f024663d 2021-09-05 stsp 	char len[5];
162 717a78d4 2022-08-16 thomas 	int i, ret;
163 f024663d 2021-09-05 stsp 	ssize_t w;
164 f024663d 2021-09-05 stsp 
165 717a78d4 2022-08-16 thomas 	ret = snprintf(len, sizeof(len), "%04x", nbuf + 4);
166 717a78d4 2022-08-16 thomas 	if (ret < 0 || (size_t)ret >= sizeof(len))
167 f024663d 2021-09-05 stsp 		return got_error(GOT_ERR_NO_SPACE);
168 f024663d 2021-09-05 stsp 	w = write(fd, len, 4);
169 f024663d 2021-09-05 stsp 	if (w == -1)
170 f024663d 2021-09-05 stsp 		return got_error_from_errno("write");
171 f024663d 2021-09-05 stsp 	if (w != 4)
172 f024663d 2021-09-05 stsp 		return got_error(GOT_ERR_IO);
173 f024663d 2021-09-05 stsp 	w = write(fd, buf, nbuf);
174 f024663d 2021-09-05 stsp 	if (w == -1)
175 f024663d 2021-09-05 stsp 		return got_error_from_errno("write");
176 f024663d 2021-09-05 stsp 	if (w != nbuf)
177 f024663d 2021-09-05 stsp 		return got_error(GOT_ERR_IO);
178 f024663d 2021-09-05 stsp 	if (chattygot > 1) {
179 f024663d 2021-09-05 stsp 		fprintf(stderr, "%s: writepkt: %s:\t", getprogname(), len);
180 f024663d 2021-09-05 stsp 		for (i = 0; i < nbuf; i++) {
181 6771d425 2022-11-17 thomas 			if (isprint((unsigned char)buf[i]))
182 f024663d 2021-09-05 stsp 				fputc(buf[i], stderr);
183 f024663d 2021-09-05 stsp 			else
184 f024663d 2021-09-05 stsp 				fprintf(stderr, "[0x%.2x]", buf[i]);
185 f024663d 2021-09-05 stsp 		}
186 f024663d 2021-09-05 stsp 		fputc('\n', stderr);
187 f024663d 2021-09-05 stsp 	}
188 f024663d 2021-09-05 stsp 	return NULL;
189 f024663d 2021-09-05 stsp }