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 
22 #include <stdint.h>
23 #include <imsg.h>
24 #include <limits.h>
25 #include <signal.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <sha1.h>
30 #include <unistd.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_object_parse.h"
40 #include "got_lib_privsep.h"
41 #include "got_lib_sha1.h"
42 
43 #ifndef nitems
44 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
45 #endif
46 
47 #define GOT_OBJ_TAG_COMMIT	"commit"
48 #define GOT_OBJ_TAG_TREE	"tree"
49 #define GOT_OBJ_TAG_BLOB	"blob"
50 #define GOT_OBJ_TAG_TAG		"tag"
51 
52 static volatile sig_atomic_t sigint_received;
53 
54 static void
55 catch_sigint(int signo)
56 {
57 	sigint_received = 1;
58 }
59 
60 static const struct got_error *
61 send_raw_obj(struct imsgbuf *ibuf, struct got_object *obj,
62     struct got_object_id *expected_id,
63     int fd, int outfd)
64 {
65 	const struct got_error *err = NULL;
66 	uint8_t *data = NULL;
67 	size_t len = 0, consumed;
68 	FILE *f;
69 	struct got_object_id id;
70 	struct got_inflate_checksum csum;
71 	SHA1_CTX sha1_ctx;
72 
73 	SHA1Init(&sha1_ctx);
74 	memset(&csum, 0, sizeof(csum));
75 	csum.output_sha1 = &sha1_ctx;
76 
77 	if (lseek(fd, SEEK_SET, 0) == -1) {
78 		err = got_error_from_errno("lseek");
79 		close(fd);
80 		return err;
81 	}
82 
83 	f = fdopen(fd, "r");
84 	if (f == NULL) {
85 		err = got_error_from_errno("fdopen");
86 		close(fd);
87 		return err;
88 	}
89 
90 	if (obj->size + obj->hdrlen <= GOT_PRIVSEP_INLINE_OBJECT_DATA_MAX)
91 		err = got_inflate_to_mem(&data, &len, &consumed, &csum, f);
92 	else
93 		err = got_inflate_to_fd(&len, f, &csum, outfd);
94 	if (err)
95 		goto done;
96 
97 	if (len < obj->hdrlen || len != obj->hdrlen + obj->size) {
98 		err = got_error(GOT_ERR_BAD_OBJ_HDR);
99 		goto done;
100 	}
101 
102 	SHA1Final(id.sha1, &sha1_ctx);
103 	if (memcmp(expected_id->sha1, id.sha1, SHA1_DIGEST_LENGTH) != 0) {
104 		char buf[SHA1_DIGEST_STRING_LENGTH];
105 		err = got_error_fmt(GOT_ERR_OBJ_CSUM,
106 		    "checksum failure for object %s",
107 		    got_sha1_digest_to_str(expected_id->sha1, buf,
108 		    sizeof(buf)));
109 		goto done;
110 	}
111 
112 
113 	err = got_privsep_send_raw_obj(ibuf, obj->size, obj->hdrlen, data);
114 
115 done:
116 	free(data);
117 	if (fclose(f) == EOF && err == NULL)
118 		err = got_error_from_errno("fclose");
119 
120 	return err;
121 }
122 
123 int
124 main(int argc, char *argv[])
125 {
126 	const struct got_error *err = NULL;
127 	struct got_object *obj = NULL;
128 	struct imsg imsg;
129 	struct imsgbuf ibuf;
130 	size_t datalen;
131 	struct got_object_id expected_id;
132 
133 	signal(SIGINT, catch_sigint);
134 
135 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
136 
137 #ifndef PROFILE
138 	/* revoke access to most system calls */
139 	if (pledge("stdio recvfd", NULL) == -1) {
140 		err = got_error_from_errno("pledge");
141 		got_privsep_send_error(&ibuf, err);
142 		return 1;
143 	}
144 #endif
145 
146 	for (;;) {
147 		if (sigint_received) {
148 			err = got_error(GOT_ERR_CANCELLED);
149 			break;
150 		}
151 
152 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
153 		if (err) {
154 			if (err->code == GOT_ERR_PRIVSEP_PIPE)
155 				err = NULL;
156 			break;
157 		}
158 
159 		if (imsg.hdr.type == GOT_IMSG_STOP)
160 			break;
161 
162 		if (imsg.hdr.type != GOT_IMSG_OBJECT_REQUEST &&
163 		    imsg.hdr.type != GOT_IMSG_RAW_OBJECT_REQUEST) {
164 			err = got_error(GOT_ERR_PRIVSEP_MSG);
165 			goto done;
166 		}
167 
168 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
169 		if (datalen != sizeof(expected_id)) {
170 			err = got_error(GOT_ERR_PRIVSEP_LEN);
171 			goto done;
172 		}
173 		memcpy(&expected_id, imsg.data, sizeof(expected_id));
174 
175 		if (imsg.fd == -1) {
176 			err = got_error(GOT_ERR_PRIVSEP_NO_FD);
177 			goto done;
178 		}
179 
180 		err = got_object_read_header(&obj, imsg.fd);
181 		if (err)
182 			goto done;
183 
184 		if (imsg.hdr.type == GOT_IMSG_RAW_OBJECT_REQUEST) {
185 			struct imsg imsg_outfd;
186 
187 			err = got_privsep_recv_imsg(&imsg_outfd, &ibuf, 0);
188 			if (err) {
189 				if (imsg_outfd.hdr.len == 0)
190 					err = NULL;
191 				goto done;
192 			}
193 
194 			if (imsg_outfd.hdr.type == GOT_IMSG_STOP) {
195 				imsg_free(&imsg_outfd);
196 				goto done;
197 			}
198 
199 			if (imsg_outfd.hdr.type != GOT_IMSG_RAW_OBJECT_OUTFD) {
200 				err = got_error(GOT_ERR_PRIVSEP_MSG);
201 				imsg_free(&imsg_outfd);
202 				goto done;
203 			}
204 
205 			datalen = imsg_outfd.hdr.len - IMSG_HEADER_SIZE;
206 			if (datalen != 0) {
207 				err = got_error(GOT_ERR_PRIVSEP_LEN);
208 				imsg_free(&imsg_outfd);
209 				goto done;
210 			}
211 			if (imsg_outfd.fd == -1) {
212 				err = got_error(GOT_ERR_PRIVSEP_NO_FD);
213 				imsg_free(&imsg_outfd);
214 				goto done;
215 			}
216 			err = send_raw_obj(&ibuf, obj, &expected_id,
217 			    imsg.fd, imsg_outfd.fd);
218 			imsg.fd = -1; /* imsg.fd is owned by send_raw_obj() */
219 			if (close(imsg_outfd.fd) == -1 && err == NULL)
220 				err = got_error_from_errno("close");
221 			imsg_free(&imsg_outfd);
222 			if (err)
223 				goto done;
224 		} else
225 			err = got_privsep_send_obj(&ibuf, obj);
226 done:
227 		if (imsg.fd != -1 && close(imsg.fd) == -1 && err == NULL)
228 			err = got_error_from_errno("close");
229 		imsg_free(&imsg);
230 		if (obj)
231 			got_object_close(obj);
232 		if (err)
233 			break;
234 	}
235 
236 	imsg_clear(&ibuf);
237 	if (err) {
238 		if(!sigint_received && err->code != GOT_ERR_PRIVSEP_PIPE) {
239 			fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
240 			got_privsep_send_error(&ibuf, err);
241 		}
242 	}
243 	if (close(GOT_IMSG_FD_CHILD) == -1 && err == NULL)
244 		err = got_error_from_errno("close");
245 	return err ? 1 : 0;
246 }