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 
42 static volatile sig_atomic_t sigint_received;
43 
44 static void
45 catch_sigint(int signo)
46 {
47 	sigint_received = 1;
48 }
49 
50 int
51 main(int argc, char *argv[])
52 {
53 	const struct got_error *err = NULL;
54 	struct imsgbuf ibuf;
55 	size_t datalen;
56 
57 	signal(SIGINT, catch_sigint);
58 
59 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
60 
61 #ifndef PROFILE
62 	/* revoke access to most system calls */
63 	if (pledge("stdio recvfd", NULL) == -1) {
64 		err = got_error_from_errno("pledge");
65 		got_privsep_send_error(&ibuf, err);
66 		return 1;
67 	}
68 #endif
69 
70 	for (;;) {
71 		struct imsg imsg, imsg_outfd;
72 		FILE *f = NULL;
73 		size_t size;
74 		struct got_object *obj = NULL;
75 		uint8_t *buf = NULL;
76 		struct got_object_id id;
77 		struct got_object_id expected_id;
78 		struct got_inflate_checksum csum;
79 		SHA1_CTX sha1_ctx;
80 
81 		SHA1Init(&sha1_ctx);
82 		memset(&csum, 0, sizeof(csum));
83 		csum.output_sha1 = &sha1_ctx;
84 
85 		memset(&imsg, 0, sizeof(imsg));
86 		imsg.fd = -1;
87 		memset(&imsg_outfd, 0, sizeof(imsg_outfd));
88 		imsg_outfd.fd = -1;
89 
90 		if (sigint_received) {
91 			err = got_error(GOT_ERR_CANCELLED);
92 			break;
93 		}
94 
95 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
96 		if (err) {
97 			if (err->code == GOT_ERR_PRIVSEP_PIPE)
98 				err = NULL;
99 			break;
100 		}
101 
102 		if (imsg.hdr.type == GOT_IMSG_STOP)
103 			break;
104 
105 		if (imsg.hdr.type != GOT_IMSG_BLOB_REQUEST) {
106 			err = got_error(GOT_ERR_PRIVSEP_MSG);
107 			goto done;
108 		}
109 
110 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
111 		if (datalen != sizeof(expected_id)) {
112 			err = got_error(GOT_ERR_PRIVSEP_LEN);
113 			goto done;
114 		}
115 		memcpy(&expected_id, imsg.data, sizeof(expected_id));
116 
117 		if (imsg.fd == -1) {
118 			err = got_error(GOT_ERR_PRIVSEP_NO_FD);
119 			goto done;
120 		}
121 
122 		err = got_privsep_recv_imsg(&imsg_outfd, &ibuf, 0);
123 		if (err) {
124 			if (imsg.hdr.len == 0)
125 				err = NULL;
126 			break;
127 		}
128 
129 		if (imsg_outfd.hdr.type == GOT_IMSG_STOP)
130 			break;
131 
132 		if (imsg_outfd.hdr.type != GOT_IMSG_BLOB_OUTFD) {
133 			err = got_error(GOT_ERR_PRIVSEP_MSG);
134 			goto done;
135 		}
136 
137 		datalen = imsg_outfd.hdr.len - IMSG_HEADER_SIZE;
138 		if (datalen != 0) {
139 			err = got_error(GOT_ERR_PRIVSEP_LEN);
140 			goto done;
141 		}
142 		if (imsg_outfd.fd == -1) {
143 			err = got_error(GOT_ERR_PRIVSEP_NO_FD);
144 			goto done;
145 		}
146 
147 		err = got_object_read_header(&obj, imsg.fd);
148 		if (err)
149 			goto done;
150 
151 		if (lseek(imsg.fd, SEEK_SET, 0) == -1) {
152 			err = got_error_from_errno("lseek");
153 			goto done;
154 		}
155 
156 		f = fdopen(imsg.fd, "rb");
157 		if (f == NULL) {
158 			err = got_error_from_errno("fdopen");
159 			goto done;
160 		}
161 
162 		if (obj->size + obj->hdrlen <=
163 		    GOT_PRIVSEP_INLINE_BLOB_DATA_MAX) {
164 			err = got_inflate_to_mem(&buf, &size, NULL, &csum, f);
165 			if (err)
166 				goto done;
167 		} else {
168 			err = got_inflate_to_fd(&size, f, &csum, imsg_outfd.fd);
169 			if (err)
170 				goto done;
171 		}
172 		SHA1Final(id.sha1, &sha1_ctx);
173 		if (got_object_id_cmp(&expected_id, &id) != 0) {
174 			err = got_error_checksum(&expected_id);
175 			goto done;
176 		}
177 
178 		if (size < obj->hdrlen) {
179 			err = got_error(GOT_ERR_BAD_OBJ_HDR);
180 			goto done;
181 		}
182 
183 		err = got_privsep_send_blob(&ibuf, size, obj->hdrlen, buf);
184 done:
185 		free(buf);
186 		if (f) {
187 			if (fclose(f) == EOF && err == NULL)
188 				err = got_error_from_errno("fclose");
189 		} else if (imsg.fd != -1) {
190 			if (close(imsg.fd) == -1 && err == NULL)
191 				err = got_error_from_errno("close");
192 		}
193 		if (imsg_outfd.fd != -1) {
194 			if (close(imsg_outfd.fd) == -1 && err == NULL)
195 				err = got_error_from_errno("close");
196 		}
197 
198 		imsg_free(&imsg);
199 		imsg_free(&imsg_outfd);
200 		if (obj)
201 			got_object_close(obj);
202 		if (err)
203 			break;
204 	}
205 
206 	imsg_clear(&ibuf);
207 	if (err) {
208 		if (!sigint_received && err->code != GOT_ERR_PRIVSEP_PIPE) {
209 			fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
210 			got_privsep_send_error(&ibuf, err);
211 		}
212 	}
213 	if (close(GOT_IMSG_FD_CHILD) == -1 && err == NULL)
214 		err = got_error_from_errno("close");
215 	return err ? 1 : 0;
216 }