1 /*
2  * Copyright (c) 2018, 2019 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 static volatile sig_atomic_t sigint_received;
44 
45 static void
46 catch_sigint(int signo)
47 {
48 	sigint_received = 1;
49 }
50 
51 int
52 main(int argc, char *argv[])
53 {
54 	const struct got_error *err = NULL;
55 	struct imsgbuf ibuf;
56 	size_t datalen;
57 
58 	signal(SIGINT, catch_sigint);
59 
60 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
61 
62 #ifndef PROFILE
63 	/* revoke access to most system calls */
64 	if (pledge("stdio recvfd", NULL) == -1) {
65 		err = got_error_from_errno("pledge");
66 		got_privsep_send_error(&ibuf, err);
67 		return 1;
68 	}
69 #endif
70 
71 	for (;;) {
72 		struct imsg imsg, imsg_outfd;
73 		FILE *f = NULL;
74 		size_t size;
75 		struct got_object *obj = NULL;
76 		uint8_t *buf = NULL;
77 		struct got_object_id id;
78 		struct got_object_id expected_id;
79 		struct got_inflate_checksum csum;
80 		SHA1_CTX sha1_ctx;
81 
82 		SHA1Init(&sha1_ctx);
83 		memset(&csum, 0, sizeof(csum));
84 		csum.output_sha1 = &sha1_ctx;
85 
86 		memset(&imsg, 0, sizeof(imsg));
87 		imsg.fd = -1;
88 		memset(&imsg_outfd, 0, sizeof(imsg_outfd));
89 		imsg_outfd.fd = -1;
90 
91 		if (sigint_received) {
92 			err = got_error(GOT_ERR_CANCELLED);
93 			break;
94 		}
95 
96 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
97 		if (err) {
98 			if (err->code == GOT_ERR_PRIVSEP_PIPE)
99 				err = NULL;
100 			break;
101 		}
102 
103 		if (imsg.hdr.type == GOT_IMSG_STOP)
104 			break;
105 
106 		if (imsg.hdr.type != GOT_IMSG_BLOB_REQUEST) {
107 			err = got_error(GOT_ERR_PRIVSEP_MSG);
108 			goto done;
109 		}
110 
111 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
112 		if (datalen != sizeof(expected_id)) {
113 			err = got_error(GOT_ERR_PRIVSEP_LEN);
114 			goto done;
115 		}
116 		memcpy(&expected_id, imsg.data, sizeof(expected_id));
117 
118 		if (imsg.fd == -1) {
119 			err = got_error(GOT_ERR_PRIVSEP_NO_FD);
120 			goto done;
121 		}
122 
123 		err = got_privsep_recv_imsg(&imsg_outfd, &ibuf, 0);
124 		if (err) {
125 			if (imsg.hdr.len == 0)
126 				err = NULL;
127 			break;
128 		}
129 
130 		if (imsg_outfd.hdr.type == GOT_IMSG_STOP)
131 			break;
132 
133 		if (imsg_outfd.hdr.type != GOT_IMSG_BLOB_OUTFD) {
134 			err = got_error(GOT_ERR_PRIVSEP_MSG);
135 			goto done;
136 		}
137 
138 		datalen = imsg_outfd.hdr.len - IMSG_HEADER_SIZE;
139 		if (datalen != 0) {
140 			err = got_error(GOT_ERR_PRIVSEP_LEN);
141 			goto done;
142 		}
143 		if (imsg_outfd.fd == -1) {
144 			err = got_error(GOT_ERR_PRIVSEP_NO_FD);
145 			goto done;
146 		}
147 
148 		err = got_object_read_header(&obj, imsg.fd);
149 		if (err)
150 			goto done;
151 
152 		if (lseek(imsg.fd, SEEK_SET, 0) == -1) {
153 			err = got_error_from_errno("lseek");
154 			goto done;
155 		}
156 
157 		f = fdopen(imsg.fd, "rb");
158 		if (f == NULL) {
159 			err = got_error_from_errno("fdopen");
160 			goto done;
161 		}
162 
163 		if (obj->size + obj->hdrlen <=
164 		    GOT_PRIVSEP_INLINE_BLOB_DATA_MAX) {
165 			err = got_inflate_to_mem(&buf, &size, NULL, &csum, f);
166 			if (err)
167 				goto done;
168 		} else {
169 			err = got_inflate_to_fd(&size, f, &csum, imsg_outfd.fd);
170 			if (err)
171 				goto done;
172 		}
173 		SHA1Final(id.sha1, &sha1_ctx);
174 		if (memcmp(expected_id.sha1, id.sha1, SHA1_DIGEST_LENGTH) != 0) {
175 			char buf[SHA1_DIGEST_STRING_LENGTH];
176 			err = got_error_fmt(GOT_ERR_OBJ_CSUM,
177 			    "checksum failure for object %s",
178 			    got_sha1_digest_to_str(expected_id.sha1, buf,
179 			    sizeof(buf)));
180 			goto done;
181 		}
182 
183 		if (size < obj->hdrlen) {
184 			err = got_error(GOT_ERR_BAD_OBJ_HDR);
185 			goto done;
186 		}
187 
188 		err = got_privsep_send_blob(&ibuf, size, obj->hdrlen, buf);
189 done:
190 		free(buf);
191 		if (f) {
192 			if (fclose(f) == EOF && err == NULL)
193 				err = got_error_from_errno("fclose");
194 		} else if (imsg.fd != -1) {
195 			if (close(imsg.fd) == -1 && err == NULL)
196 				err = got_error_from_errno("close");
197 		}
198 		if (imsg_outfd.fd != -1) {
199 			if (close(imsg_outfd.fd) == -1 && err == NULL)
200 				err = got_error_from_errno("close");
201 		}
202 
203 		imsg_free(&imsg);
204 		imsg_free(&imsg_outfd);
205 		if (obj)
206 			got_object_close(obj);
207 		if (err)
208 			break;
209 	}
210 
211 	imsg_clear(&ibuf);
212 	if (err) {
213 		if (!sigint_received && err->code != GOT_ERR_PRIVSEP_PIPE) {
214 			fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
215 			got_privsep_send_error(&ibuf, err);
216 		}
217 	}
218 	if (close(GOT_IMSG_FD_CHILD) == -1 && err == NULL)
219 		err = got_error_from_errno("close");
220 	return err ? 1 : 0;
221 }