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 <sha2.h>
31 #include <unistd.h>
32 #include <zlib.h>
33 
34 #include "got_error.h"
35 #include "got_object.h"
36 
37 #include "got_lib_delta.h"
38 #include "got_lib_hash.h"
39 #include "got_lib_inflate.h"
40 #include "got_lib_object.h"
41 #include "got_lib_object_parse.h"
42 #include "got_lib_privsep.h"
43 
44 static volatile sig_atomic_t sigint_received;
45 
46 static void
47 catch_sigint(int signo)
48 {
49 	sigint_received = 1;
50 }
51 
52 int
53 main(int argc, char *argv[])
54 {
55 	const struct got_error *err = NULL;
56 	struct imsgbuf ibuf;
57 	size_t datalen;
58 
59 	signal(SIGINT, catch_sigint);
60 
61 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
62 
63 #ifndef PROFILE
64 	/* revoke access to most system calls */
65 	if (pledge("stdio recvfd", NULL) == -1) {
66 		err = got_error_from_errno("pledge");
67 		got_privsep_send_error(&ibuf, err);
68 		return 1;
69 	}
70 #endif
71 
72 	for (;;) {
73 		struct imsg imsg, imsg_outfd;
74 		FILE *f = NULL;
75 		int fd = -1, outfd = -1;
76 		size_t size;
77 		struct got_object *obj = NULL;
78 		uint8_t *buf = NULL;
79 		struct got_object_id id;
80 		struct got_object_id expected_id;
81 		struct got_inflate_checksum csum;
82 		struct got_hash ctx;
83 
84 		got_hash_init(&ctx, GOT_HASH_SHA1);
85 		memset(&csum, 0, sizeof(csum));
86 		csum.output_ctx = &ctx;
87 
88 		memset(&imsg, 0, sizeof(imsg));
89 		memset(&imsg_outfd, 0, sizeof(imsg_outfd));
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 		fd = imsg_get_fd(&imsg);
119 		if (fd == -1) {
120 			err = got_error(GOT_ERR_PRIVSEP_NO_FD);
121 			goto done;
122 		}
123 
124 		err = got_privsep_recv_imsg(&imsg_outfd, &ibuf, 0);
125 		if (err) {
126 			if (imsg.hdr.len == 0)
127 				err = NULL;
128 			break;
129 		}
130 
131 		if (imsg_outfd.hdr.type == GOT_IMSG_STOP)
132 			break;
133 
134 		if (imsg_outfd.hdr.type != GOT_IMSG_BLOB_OUTFD) {
135 			err = got_error(GOT_ERR_PRIVSEP_MSG);
136 			goto done;
137 		}
138 
139 		datalen = imsg_outfd.hdr.len - IMSG_HEADER_SIZE;
140 		if (datalen != 0) {
141 			err = got_error(GOT_ERR_PRIVSEP_LEN);
142 			goto done;
143 		}
144 		outfd = imsg_get_fd(&imsg_outfd);
145 		if (outfd == -1) {
146 			err = got_error(GOT_ERR_PRIVSEP_NO_FD);
147 			goto done;
148 		}
149 
150 		err = got_object_read_header(&obj, fd);
151 		if (err)
152 			goto done;
153 
154 		if (lseek(fd, SEEK_SET, 0) == -1) {
155 			err = got_error_from_errno("lseek");
156 			goto done;
157 		}
158 
159 		f = fdopen(fd, "rb");
160 		if (f == NULL) {
161 			err = got_error_from_errno("fdopen");
162 			goto done;
163 		}
164 		fd = -1;
165 
166 		if (obj->size + obj->hdrlen <=
167 		    GOT_PRIVSEP_INLINE_BLOB_DATA_MAX) {
168 			err = got_inflate_to_mem(&buf, &size, NULL, &csum, f);
169 			if (err)
170 				goto done;
171 		} else {
172 			err = got_inflate_to_fd(&size, f, &csum, outfd);
173 			if (err)
174 				goto done;
175 		}
176 		got_hash_final_object_id(&ctx, &id);
177 		if (got_object_id_cmp(&expected_id, &id) != 0) {
178 			err = got_error_checksum(&expected_id);
179 			goto done;
180 		}
181 
182 		if (size < obj->hdrlen) {
183 			err = got_error(GOT_ERR_BAD_OBJ_HDR);
184 			goto done;
185 		}
186 
187 		err = got_privsep_send_blob(&ibuf, size, obj->hdrlen, buf);
188 done:
189 		free(buf);
190 		if (f && fclose(f) == EOF && err == NULL)
191 			err = got_error_from_errno("fclose");
192 		if (fd != -1 && close(fd) == -1 && err == NULL)
193 			err = got_error_from_errno("close");
194 		if (outfd != -1 && close(outfd) == -1 && err == NULL)
195 			err = got_error_from_errno("close");
196 
197 		imsg_free(&imsg);
198 		imsg_free(&imsg_outfd);
199 		if (obj)
200 			got_object_close(obj);
201 		if (err)
202 			break;
203 	}
204 
205 	imsg_clear(&ibuf);
206 	if (err) {
207 		if (!sigint_received && err->code != GOT_ERR_PRIVSEP_PIPE) {
208 			fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
209 			got_privsep_send_error(&ibuf, err);
210 		}
211 	}
212 	if (close(GOT_IMSG_FD_CHILD) == -1 && err == NULL)
213 		err = got_error_from_errno("close");
214 	return err ? 1 : 0;
215 }