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 336075a4 2022-06-25 op #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 695bc1ec 2023-01-21 stsp 			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 f024663d 2021-09-05 stsp /*
 62 f024663d 2021-09-05 stsp  * Packet header contains a 4-byte hexstring which specifies the length
 63 f024663d 2021-09-05 stsp  * of data which follows.
 64 f024663d 2021-09-05 stsp  */
 65 f024663d 2021-09-05 stsp const struct got_error *
 66 f024663d 2021-09-05 stsp got_pkt_readhdr(int *datalen, int fd, int chattygot)
 67 f024663d 2021-09-05 stsp {
 68 f024663d 2021-09-05 stsp 	static const struct got_error *err = NULL;
 69 f024663d 2021-09-05 stsp 	char lenstr[5];
 70 f024663d 2021-09-05 stsp 	long len;
 71 f024663d 2021-09-05 stsp 	char *e;
 72 f024663d 2021-09-05 stsp 	int n, i;
 73 f024663d 2021-09-05 stsp 	ssize_t r;
 74 f024663d 2021-09-05 stsp 
 75 f024663d 2021-09-05 stsp 	*datalen = 0;
 76 f024663d 2021-09-05 stsp 
 77 f024663d 2021-09-05 stsp 	err = got_pkt_readn(&r, fd, lenstr, 4);
 78 f024663d 2021-09-05 stsp 	if (err)
 79 f024663d 2021-09-05 stsp 		return err;
 80 f024663d 2021-09-05 stsp 	if (r == 0) {
 81 f024663d 2021-09-05 stsp 		/* implicit "0000" */
 82 f024663d 2021-09-05 stsp 		if (chattygot > 1)
 83 f024663d 2021-09-05 stsp 			fprintf(stderr, "%s: readpkt: 0000\n", getprogname());
 84 f024663d 2021-09-05 stsp 		return NULL;
 85 f024663d 2021-09-05 stsp 	}
 86 f024663d 2021-09-05 stsp 	if (r != 4)
 87 f024663d 2021-09-05 stsp 		return got_error_msg(GOT_ERR_BAD_PACKET,
 88 f024663d 2021-09-05 stsp 		    "wrong packet header length");
 89 f024663d 2021-09-05 stsp 
 90 f024663d 2021-09-05 stsp 	lenstr[4] = '\0';
 91 f024663d 2021-09-05 stsp 	for (i = 0; i < 4; i++) {
 92 f024663d 2021-09-05 stsp 		if (!isprint((unsigned char)lenstr[i]))
 93 f024663d 2021-09-05 stsp 			return got_error_msg(GOT_ERR_BAD_PACKET,
 94 f024663d 2021-09-05 stsp 			    "unprintable character in packet length field");
 95 f024663d 2021-09-05 stsp 	}
 96 f024663d 2021-09-05 stsp 	for (i = 0; i < 4; i++) {
 97 f024663d 2021-09-05 stsp 		if (!isxdigit((unsigned char)lenstr[i])) {
 98 f024663d 2021-09-05 stsp 			if (chattygot)
 99 f024663d 2021-09-05 stsp 				fprintf(stderr, "%s: bad length: '%s'\n",
100 f024663d 2021-09-05 stsp 				    getprogname(), lenstr);
101 f024663d 2021-09-05 stsp 			return got_error_msg(GOT_ERR_BAD_PACKET,
102 f024663d 2021-09-05 stsp 			    "packet length not specified in hex");
103 f024663d 2021-09-05 stsp 		}
104 f024663d 2021-09-05 stsp 	}
105 f024663d 2021-09-05 stsp 	errno = 0;
106 f024663d 2021-09-05 stsp 	len = strtol(lenstr, &e, 16);
107 f024663d 2021-09-05 stsp 	if (lenstr[0] == '\0' || *e != '\0')
108 f024663d 2021-09-05 stsp 		return got_error(GOT_ERR_BAD_PACKET);
109 f024663d 2021-09-05 stsp 	if (errno == ERANGE && (len == LONG_MAX || len == LONG_MIN))
110 f024663d 2021-09-05 stsp 		return got_error_msg(GOT_ERR_BAD_PACKET, "bad packet length");
111 f024663d 2021-09-05 stsp 	if (len > INT_MAX || len < INT_MIN)
112 f024663d 2021-09-05 stsp 		return got_error_msg(GOT_ERR_BAD_PACKET, "bad packet length");
113 f024663d 2021-09-05 stsp 	n = len;
114 f024663d 2021-09-05 stsp 	if (n == 0)
115 f024663d 2021-09-05 stsp 		return NULL;
116 f024663d 2021-09-05 stsp 	if (n <= 4)
117 f024663d 2021-09-05 stsp 		return got_error_msg(GOT_ERR_BAD_PACKET, "packet too short");
118 f024663d 2021-09-05 stsp 	n  -= 4;
119 f024663d 2021-09-05 stsp 
120 f024663d 2021-09-05 stsp 	*datalen = n;
121 f024663d 2021-09-05 stsp 	return NULL;
122 f024663d 2021-09-05 stsp }
123 f024663d 2021-09-05 stsp 
124 f024663d 2021-09-05 stsp const struct got_error *
125 f024663d 2021-09-05 stsp got_pkt_readpkt(int *outlen, int fd, char *buf, int buflen, int chattygot)
126 f024663d 2021-09-05 stsp {
127 f024663d 2021-09-05 stsp 	const struct got_error *err = NULL;
128 f024663d 2021-09-05 stsp 	int datalen, i;
129 f024663d 2021-09-05 stsp 	ssize_t n;
130 f024663d 2021-09-05 stsp 
131 f024663d 2021-09-05 stsp 	err = got_pkt_readhdr(&datalen, fd, chattygot);
132 f024663d 2021-09-05 stsp 	if (err)
133 f024663d 2021-09-05 stsp 		return err;
134 f024663d 2021-09-05 stsp 
135 f024663d 2021-09-05 stsp 	if (datalen > buflen)
136 f024663d 2021-09-05 stsp 		return got_error(GOT_ERR_NO_SPACE);
137 f024663d 2021-09-05 stsp 
138 f024663d 2021-09-05 stsp 	err = got_pkt_readn(&n, fd, buf, datalen);
139 f024663d 2021-09-05 stsp 	if (err)
140 f024663d 2021-09-05 stsp 		return err;
141 f024663d 2021-09-05 stsp 	if (n != datalen)
142 f024663d 2021-09-05 stsp 		return got_error_msg(GOT_ERR_BAD_PACKET, "short packet");
143 f024663d 2021-09-05 stsp 
144 f024663d 2021-09-05 stsp 	if (chattygot > 1) {
145 f024663d 2021-09-05 stsp 		fprintf(stderr, "%s: readpkt: %zd:\t", getprogname(), n);
146 f024663d 2021-09-05 stsp 		for (i = 0; i < n; i++) {
147 99fd9ff4 2022-11-17 op 			if (isprint((unsigned char)buf[i]))
148 f024663d 2021-09-05 stsp 				fputc(buf[i], stderr);
149 f024663d 2021-09-05 stsp 			else
150 f024663d 2021-09-05 stsp 				fprintf(stderr, "[0x%.2x]", buf[i]);
151 f024663d 2021-09-05 stsp 		}
152 f024663d 2021-09-05 stsp 		fputc('\n', stderr);
153 f024663d 2021-09-05 stsp 	}
154 f024663d 2021-09-05 stsp 
155 f024663d 2021-09-05 stsp 	*outlen = n;
156 f024663d 2021-09-05 stsp 	return NULL;
157 f024663d 2021-09-05 stsp }
158 f024663d 2021-09-05 stsp 
159 f024663d 2021-09-05 stsp const struct got_error *
160 f024663d 2021-09-05 stsp got_pkt_writepkt(int fd, char *buf, int nbuf, int chattygot)
161 f024663d 2021-09-05 stsp {
162 f024663d 2021-09-05 stsp 	char len[5];
163 438d0cc3 2022-08-16 op 	int i, ret;
164 f024663d 2021-09-05 stsp 	ssize_t w;
165 f024663d 2021-09-05 stsp 
166 438d0cc3 2022-08-16 op 	ret = snprintf(len, sizeof(len), "%04x", nbuf + 4);
167 438d0cc3 2022-08-16 op 	if (ret < 0 || (size_t)ret >= sizeof(len))
168 f024663d 2021-09-05 stsp 		return got_error(GOT_ERR_NO_SPACE);
169 f024663d 2021-09-05 stsp 	w = write(fd, len, 4);
170 f024663d 2021-09-05 stsp 	if (w == -1)
171 f024663d 2021-09-05 stsp 		return got_error_from_errno("write");
172 f024663d 2021-09-05 stsp 	if (w != 4)
173 f024663d 2021-09-05 stsp 		return got_error(GOT_ERR_IO);
174 f024663d 2021-09-05 stsp 	w = write(fd, buf, nbuf);
175 f024663d 2021-09-05 stsp 	if (w == -1)
176 f024663d 2021-09-05 stsp 		return got_error_from_errno("write");
177 f024663d 2021-09-05 stsp 	if (w != nbuf)
178 f024663d 2021-09-05 stsp 		return got_error(GOT_ERR_IO);
179 f024663d 2021-09-05 stsp 	if (chattygot > 1) {
180 f024663d 2021-09-05 stsp 		fprintf(stderr, "%s: writepkt: %s:\t", getprogname(), len);
181 f024663d 2021-09-05 stsp 		for (i = 0; i < nbuf; i++) {
182 99fd9ff4 2022-11-17 op 			if (isprint((unsigned char)buf[i]))
183 f024663d 2021-09-05 stsp 				fputc(buf[i], stderr);
184 f024663d 2021-09-05 stsp 			else
185 f024663d 2021-09-05 stsp 				fprintf(stderr, "[0x%.2x]", buf[i]);
186 f024663d 2021-09-05 stsp 		}
187 f024663d 2021-09-05 stsp 		fputc('\n', stderr);
188 f024663d 2021-09-05 stsp 	}
189 f024663d 2021-09-05 stsp 	return NULL;
190 f024663d 2021-09-05 stsp }