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 <signal.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <sha1.h>
31 #include <zlib.h>
32 
33 #include "got_error.h"
34 #include "got_object.h"
35 
36 #include "got_lib_delta.h"
37 #include "got_lib_inflate.h"
38 #include "got_lib_object.h"
39 #include "got_lib_privsep.h"
40 
41 #ifndef nitems
42 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
43 #endif
44 
45 #define GOT_OBJ_TAG_COMMIT	"commit"
46 #define GOT_OBJ_TAG_TREE	"tree"
47 #define GOT_OBJ_TAG_BLOB	"blob"
48 #define GOT_OBJ_TAG_TAG		"tag"
49 
50 static volatile sig_atomic_t sigint_received;
51 
52 static void
53 catch_sigint(int signo)
54 {
55 	sigint_received = 1;
56 }
57 
58 static const struct got_error *
59 parse_object_header(struct got_object **obj, char *buf, size_t len)
60 {
61 	const char *obj_tags[] = {
62 		GOT_OBJ_TAG_COMMIT,
63 		GOT_OBJ_TAG_TREE,
64 		GOT_OBJ_TAG_BLOB,
65 		GOT_OBJ_TAG_TAG,
66 	};
67 	const int obj_types[] = {
68 		GOT_OBJ_TYPE_COMMIT,
69 		GOT_OBJ_TYPE_TREE,
70 		GOT_OBJ_TYPE_BLOB,
71 		GOT_OBJ_TYPE_TAG,
72 	};
73 	int type = 0;
74 	size_t size = 0, hdrlen = 0;
75 	int i;
76 	char *p = strchr(buf, '\0');
77 
78 	*obj = NULL;
79 
80 	if (p == NULL)
81 		return got_error(GOT_ERR_BAD_OBJ_HDR);
82 
83 	hdrlen = strlen(buf) + 1 /* '\0' */;
84 
85 	for (i = 0; i < nitems(obj_tags); i++) {
86 		const char *tag = obj_tags[i];
87 		size_t tlen = strlen(tag);
88 		const char *errstr;
89 
90 		if (strncmp(buf, tag, tlen) != 0)
91 			continue;
92 
93 		type = obj_types[i];
94 		if (len <= tlen)
95 			return got_error(GOT_ERR_BAD_OBJ_HDR);
96 		size = strtonum(buf + tlen, 0, LONG_MAX, &errstr);
97 		if (errstr != NULL)
98 			return got_error(GOT_ERR_BAD_OBJ_HDR);
99 		break;
100 	}
101 
102 	if (type == 0)
103 		return got_error(GOT_ERR_BAD_OBJ_HDR);
104 
105 	*obj = calloc(1, sizeof(**obj));
106 	if (*obj == NULL)
107 		return got_error_from_errno();
108 	(*obj)->type = type;
109 	(*obj)->hdrlen = hdrlen;
110 	(*obj)->size = size;
111 	return NULL;
112 }
113 
114 static const struct got_error *
115 read_object_header(struct got_object **obj, int fd)
116 {
117 	const struct got_error *err;
118 	struct got_zstream_buf zb;
119 	char *buf;
120 	const size_t zbsize = 64;
121 	size_t outlen, totlen;
122 	int nbuf = 1;
123 
124 	*obj = NULL;
125 
126 	buf = malloc(zbsize);
127 	if (buf == NULL)
128 		return got_error_from_errno();
129 
130 	err = got_inflate_init(&zb, buf, zbsize);
131 	if (err)
132 		return err;
133 
134 	totlen = 0;
135 	do {
136 		err = got_inflate_read_fd(&zb, fd, &outlen);
137 		if (err)
138 			goto done;
139 		if (outlen == 0)
140 			break;
141 		totlen += outlen;
142 		if (strchr(zb.outbuf, '\0') == NULL) {
143 			char *newbuf;
144 			nbuf++;
145 			newbuf = recallocarray(buf, nbuf - 1, nbuf, zbsize);
146 			if (newbuf == NULL) {
147 				err = got_error_from_errno();
148 				goto done;
149 			}
150 			buf = newbuf;
151 			zb.outbuf = newbuf + totlen;
152 			zb.outlen = (nbuf * zbsize) - totlen;
153 		}
154 	} while (strchr(zb.outbuf, '\0') == NULL);
155 
156 	err = parse_object_header(obj, buf, totlen);
157 done:
158 	free(buf);
159 	got_inflate_end(&zb);
160 	return err;
161 }
162 
163 
164 int
165 main(int argc, char *argv[])
166 {
167 	const struct got_error *err = NULL;
168 	struct got_object *obj = NULL;
169 	struct imsg imsg;
170 	struct imsgbuf ibuf;
171 	size_t datalen;
172 
173 	signal(SIGINT, catch_sigint);
174 
175 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
176 
177 #ifndef PROFILE
178 	/* revoke access to most system calls */
179 	if (pledge("stdio recvfd", NULL) == -1) {
180 		err = got_error_from_errno();
181 		got_privsep_send_error(&ibuf, err);
182 		return 1;
183 	}
184 #endif
185 
186 	while (1) {
187 		if (sigint_received) {
188 			err = got_error(GOT_ERR_CANCELLED);
189 			break;
190 		}
191 
192 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
193 		if (err) {
194 			if (err->code == GOT_ERR_PRIVSEP_PIPE)
195 				err = NULL;
196 			break;
197 		}
198 
199 		if (imsg.hdr.type == GOT_IMSG_STOP)
200 			break;
201 
202 		if (imsg.hdr.type != GOT_IMSG_OBJECT_REQUEST) {
203 			err = got_error(GOT_ERR_PRIVSEP_MSG);
204 			goto done;
205 		}
206 
207 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
208 		if (datalen != 0) {
209 			err = got_error(GOT_ERR_PRIVSEP_LEN);
210 			goto done;
211 		}
212 
213 		err = read_object_header(&obj, imsg.fd);
214 		if (err)
215 			goto done;
216 
217 		err = got_privsep_send_obj(&ibuf, obj);
218 done:
219 		close(imsg.fd);
220 		imsg_free(&imsg);
221 		if (obj)
222 			got_object_close(obj);
223 		if (err)
224 			break;
225 	}
226 
227 	imsg_clear(&ibuf);
228 	if (err) {
229 		if(!sigint_received && err->code != GOT_ERR_PRIVSEP_PIPE) {
230 			fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
231 			got_privsep_send_error(&ibuf, err);
232 		}
233 	}
234 	close(GOT_IMSG_FD_CHILD);
235 	return err ? 1 : 0;
236 }