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