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 
23 #include <stdint.h>
24 #include <imsg.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <sha1.h>
29 #include <zlib.h>
30 
31 #include "got_error.h"
32 #include "got_object.h"
33 
34 #include "got_lib_delta.h"
35 #include "got_lib_inflate.h"
36 #include "got_lib_object.h"
37 #include "got_lib_privsep.h"
38 
39 #ifndef nitems
40 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
41 #endif
42 
43 #define GOT_OBJ_TAG_COMMIT	"commit"
44 #define GOT_OBJ_TAG_TREE	"tree"
45 #define GOT_OBJ_TAG_BLOB	"blob"
46 
47 static const struct got_error *
48 parse_object_header(struct got_object **obj, char *buf, size_t len)
49 {
50 	const char *obj_tags[] = {
51 		GOT_OBJ_TAG_COMMIT,
52 		GOT_OBJ_TAG_TREE,
53 		GOT_OBJ_TAG_BLOB
54 	};
55 	const int obj_types[] = {
56 		GOT_OBJ_TYPE_COMMIT,
57 		GOT_OBJ_TYPE_TREE,
58 		GOT_OBJ_TYPE_BLOB,
59 	};
60 	int type = 0;
61 	size_t size = 0, hdrlen = 0;
62 	int i;
63 	char *p = strchr(buf, '\0');
64 
65 	if (p == NULL)
66 		return got_error(GOT_ERR_BAD_OBJ_HDR);
67 
68 	hdrlen = strlen(buf) + 1 /* '\0' */;
69 
70 	for (i = 0; i < nitems(obj_tags); i++) {
71 		const char *tag = obj_tags[i];
72 		size_t tlen = strlen(tag);
73 		const char *errstr;
74 
75 		if (strncmp(buf, tag, tlen) != 0)
76 			continue;
77 
78 		type = obj_types[i];
79 		if (len <= tlen)
80 			return got_error(GOT_ERR_BAD_OBJ_HDR);
81 		size = strtonum(buf + tlen, 0, LONG_MAX, &errstr);
82 		if (errstr != NULL)
83 			return got_error(GOT_ERR_BAD_OBJ_HDR);
84 		break;
85 	}
86 
87 	if (type == 0)
88 		return got_error(GOT_ERR_BAD_OBJ_HDR);
89 
90 	*obj = calloc(1, sizeof(**obj));
91 	if (*obj == NULL)
92 		return got_error_from_errno();
93 	(*obj)->type = type;
94 	(*obj)->hdrlen = hdrlen;
95 	(*obj)->size = size;
96 	return NULL;
97 }
98 
99 static const struct got_error *
100 read_object_header(struct got_object **obj, int fd)
101 {
102 	const struct got_error *err;
103 	struct got_zstream_buf zb;
104 	char *buf;
105 	const size_t zbsize = 64;
106 	size_t outlen, totlen;
107 	int nbuf = 1;
108 
109 	buf = malloc(zbsize);
110 	if (buf == NULL)
111 		return got_error_from_errno();
112 
113 	err = got_inflate_init(&zb, buf, zbsize);
114 	if (err)
115 		return err;
116 
117 	totlen = 0;
118 	do {
119 		err = got_inflate_read_fd(&zb, fd, &outlen);
120 		if (err)
121 			goto done;
122 		if (outlen == 0)
123 			break;
124 		totlen += outlen;
125 		if (strchr(zb.outbuf, '\0') == NULL) {
126 			char *newbuf;
127 			nbuf++;
128 			newbuf = recallocarray(buf, nbuf - 1, nbuf, zbsize);
129 			if (newbuf == NULL) {
130 				err = got_error_from_errno();
131 				goto done;
132 			}
133 			buf = newbuf;
134 			zb.outbuf = newbuf + totlen;
135 			zb.outlen = (nbuf * zbsize) - totlen;
136 		}
137 	} while (strchr(zb.outbuf, '\0') == NULL);
138 
139 	err = parse_object_header(obj, buf, totlen);
140 done:
141 	free(buf);
142 	got_inflate_end(&zb);
143 	return err;
144 }
145 
146 
147 int
148 main(int argc, char *argv[])
149 {
150 	const struct got_error *err = NULL;
151 	struct got_object *obj = NULL;
152 	struct imsg imsg;
153 	struct imsgbuf ibuf;
154 	size_t datalen;
155 
156 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
157 
158 	/* revoke access to most system calls */
159 	if (pledge("stdio recvfd", NULL) == -1) {
160 		err = got_error_from_errno();
161 		got_privsep_send_error(&ibuf, err);
162 		return 1;
163 	}
164 
165 	while (1) {
166 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
167 		if (err) {
168 			if (imsg.hdr.len == 0)
169 				err = NULL;
170 			break;
171 		}
172 
173 		if (imsg.hdr.type == GOT_IMSG_STOP)
174 			break;
175 
176 		if (imsg.hdr.type != GOT_IMSG_OBJECT_REQUEST) {
177 			err = got_error(GOT_ERR_PRIVSEP_MSG);
178 			goto done;
179 		}
180 
181 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
182 		if (datalen != 0) {
183 			err = got_error(GOT_ERR_PRIVSEP_LEN);
184 			goto done;
185 		}
186 
187 		err = read_object_header(&obj, imsg.fd);
188 		if (err)
189 			goto done;
190 
191 		err = got_privsep_send_obj(&ibuf, obj, 0);
192 done:
193 		close(imsg.fd);
194 		imsg_free(&imsg);
195 		if (obj)
196 			got_object_close(obj);
197 		if (err) {
198 			got_privsep_send_error(&ibuf, err);
199 			break;
200 		}
201 	}
202 
203 	imsg_clear(&ibuf);
204 	if (err)
205 		fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
206 	close(GOT_IMSG_FD_CHILD);
207 	return err ? 1 : 0;
208 }