1 /*
2  * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/types.h>
18 #include <sys/queue.h>
19 #include <sys/uio.h>
20 #include <sys/time.h>
21 #include <sys/limits.h>
22 #include <sys/syslimits.h>
23 
24 #include <stdint.h>
25 #include <imsg.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <sha1.h>
30 #include <zlib.h>
31 
32 #include "got_error.h"
33 #include "got_object.h"
34 
35 #include "got_lib_delta.h"
36 #include "got_lib_inflate.h"
37 #include "got_lib_object.h"
38 #include "got_lib_privsep.h"
39 
40 #ifndef nitems
41 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
42 #endif
43 
44 #define GOT_OBJ_TAG_COMMIT	"commit"
45 #define GOT_OBJ_TAG_TREE	"tree"
46 #define GOT_OBJ_TAG_BLOB	"blob"
47 
48 static const struct got_error *
49 parse_object_header(struct got_object **obj, char *buf, size_t len)
50 {
51 	const char *obj_tags[] = {
52 		GOT_OBJ_TAG_COMMIT,
53 		GOT_OBJ_TAG_TREE,
54 		GOT_OBJ_TAG_BLOB
55 	};
56 	const int obj_types[] = {
57 		GOT_OBJ_TYPE_COMMIT,
58 		GOT_OBJ_TYPE_TREE,
59 		GOT_OBJ_TYPE_BLOB,
60 	};
61 	int type = 0;
62 	size_t size = 0, hdrlen = 0;
63 	int i;
64 	char *p = strchr(buf, '\0');
65 
66 	if (p == NULL)
67 		return got_error(GOT_ERR_BAD_OBJ_HDR);
68 
69 	hdrlen = strlen(buf) + 1 /* '\0' */;
70 
71 	for (i = 0; i < nitems(obj_tags); i++) {
72 		const char *tag = obj_tags[i];
73 		size_t tlen = strlen(tag);
74 		const char *errstr;
75 
76 		if (strncmp(buf, tag, tlen) != 0)
77 			continue;
78 
79 		type = obj_types[i];
80 		if (len <= tlen)
81 			return got_error(GOT_ERR_BAD_OBJ_HDR);
82 		size = strtonum(buf + tlen, 0, LONG_MAX, &errstr);
83 		if (errstr != NULL)
84 			return got_error(GOT_ERR_BAD_OBJ_HDR);
85 		break;
86 	}
87 
88 	if (type == 0)
89 		return got_error(GOT_ERR_BAD_OBJ_HDR);
90 
91 	*obj = calloc(1, sizeof(**obj));
92 	if (*obj == NULL)
93 		return got_error_from_errno();
94 	(*obj)->type = type;
95 	(*obj)->hdrlen = hdrlen;
96 	(*obj)->size = size;
97 	return NULL;
98 }
99 
100 static const struct got_error *
101 read_object_header(struct got_object **obj, int fd)
102 {
103 	const struct got_error *err;
104 	struct got_zstream_buf zb;
105 	char *buf;
106 	const size_t zbsize = 64;
107 	size_t outlen, totlen;
108 	int nbuf = 1;
109 
110 	buf = malloc(zbsize);
111 	if (buf == NULL)
112 		return got_error_from_errno();
113 
114 	err = got_inflate_init(&zb, buf, zbsize);
115 	if (err)
116 		return err;
117 
118 	totlen = 0;
119 	do {
120 		err = got_inflate_read_fd(&zb, fd, &outlen);
121 		if (err)
122 			goto done;
123 		if (outlen == 0)
124 			break;
125 		totlen += outlen;
126 		if (strchr(zb.outbuf, '\0') == NULL) {
127 			char *newbuf;
128 			nbuf++;
129 			newbuf = recallocarray(buf, nbuf - 1, nbuf, zbsize);
130 			if (newbuf == NULL) {
131 				err = got_error_from_errno();
132 				goto done;
133 			}
134 			buf = newbuf;
135 			zb.outbuf = newbuf + totlen;
136 			zb.outlen = (nbuf * zbsize) - totlen;
137 		}
138 	} while (strchr(zb.outbuf, '\0') == NULL);
139 
140 	err = parse_object_header(obj, buf, totlen);
141 done:
142 	free(buf);
143 	got_inflate_end(&zb);
144 	return err;
145 }
146 
147 
148 int
149 main(int argc, char *argv[])
150 {
151 	const struct got_error *err = NULL;
152 	struct got_object *obj = NULL;
153 	struct imsg imsg;
154 	struct imsgbuf ibuf;
155 	size_t datalen;
156 
157 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
158 
159 	/* revoke access to most system calls */
160 	if (pledge("stdio recvfd", NULL) == -1) {
161 		err = got_error_from_errno();
162 		got_privsep_send_error(&ibuf, err);
163 		return 1;
164 	}
165 
166 	while (1) {
167 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
168 		if (err) {
169 			if (err->code == GOT_ERR_PRIVSEP_PIPE)
170 				err = NULL;
171 			break;
172 		}
173 
174 		if (imsg.hdr.type == GOT_IMSG_STOP)
175 			break;
176 
177 		if (imsg.hdr.type != GOT_IMSG_OBJECT_REQUEST) {
178 			err = got_error(GOT_ERR_PRIVSEP_MSG);
179 			goto done;
180 		}
181 
182 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
183 		if (datalen != 0) {
184 			err = got_error(GOT_ERR_PRIVSEP_LEN);
185 			goto done;
186 		}
187 
188 		err = read_object_header(&obj, imsg.fd);
189 		if (err)
190 			goto done;
191 
192 		err = got_privsep_send_obj(&ibuf, obj);
193 done:
194 		close(imsg.fd);
195 		imsg_free(&imsg);
196 		if (obj)
197 			got_object_close(obj);
198 		if (err) {
199 			if (err->code == GOT_ERR_PRIVSEP_PIPE)
200 				err = NULL;
201 			else
202 				got_privsep_send_error(&ibuf, err);
203 			break;
204 		}
205 	}
206 
207 	imsg_clear(&ibuf);
208 	if (err)
209 		fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
210 	close(GOT_IMSG_FD_CHILD);
211 	return err ? 1 : 0;
212 }