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 #include <sys/syslimits.h>
22 
23 #include <stdint.h>
24 #include <imsg.h>
25 #include <limits.h>
26 #include <signal.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <sha1.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_inflate.h"
39 #include "got_lib_object.h"
40 #include "got_lib_object_parse.h"
41 #include "got_lib_privsep.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 
78 		memset(&imsg, 0, sizeof(imsg));
79 		imsg.fd = -1;
80 		memset(&imsg_outfd, 0, sizeof(imsg_outfd));
81 		imsg_outfd.fd = -1;
82 
83 		if (sigint_received) {
84 			err = got_error(GOT_ERR_CANCELLED);
85 			break;
86 		}
87 
88 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
89 		if (err) {
90 			if (err->code == GOT_ERR_PRIVSEP_PIPE)
91 				err = NULL;
92 			break;
93 		}
94 
95 		if (imsg.hdr.type == GOT_IMSG_STOP)
96 			break;
97 
98 		if (imsg.hdr.type != GOT_IMSG_BLOB_REQUEST) {
99 			err = got_error(GOT_ERR_PRIVSEP_MSG);
100 			goto done;
101 		}
102 
103 		if (imsg.fd == -1) {
104 			err = got_error(GOT_ERR_PRIVSEP_NO_FD);
105 			goto done;
106 		}
107 
108 		err = got_privsep_recv_imsg(&imsg_outfd, &ibuf, 0);
109 		if (err) {
110 			if (imsg.hdr.len == 0)
111 				err = NULL;
112 			break;
113 		}
114 
115 		if (imsg_outfd.hdr.type == GOT_IMSG_STOP)
116 			break;
117 
118 		if (imsg_outfd.hdr.type != GOT_IMSG_BLOB_OUTFD) {
119 			err = got_error(GOT_ERR_PRIVSEP_MSG);
120 			goto done;
121 		}
122 
123 		datalen = imsg_outfd.hdr.len - IMSG_HEADER_SIZE;
124 		if (datalen != 0) {
125 			err = got_error(GOT_ERR_PRIVSEP_LEN);
126 			goto done;
127 		}
128 		if (imsg_outfd.fd == -1) {
129 			err = got_error(GOT_ERR_PRIVSEP_NO_FD);
130 			goto done;
131 		}
132 
133 		err = got_object_read_header(&obj, imsg.fd);
134 		if (err)
135 			goto done;
136 
137 		if (lseek(imsg.fd, SEEK_SET, 0) == -1) {
138 			err = got_error_from_errno("lseek");
139 			goto done;
140 		}
141 
142 		f = fdopen(imsg.fd, "rb");
143 		if (f == NULL) {
144 			err = got_error_from_errno("fdopen");
145 			goto done;
146 		}
147 
148 		if (obj->size + obj->hdrlen <=
149 		    GOT_PRIVSEP_INLINE_BLOB_DATA_MAX) {
150 			err = got_inflate_to_mem(&buf, &size, NULL, f);
151 			if (err)
152 				goto done;
153 		} else {
154 			err = got_inflate_to_fd(&size, f, imsg_outfd.fd);
155 			if (err)
156 				goto done;
157 		}
158 
159 		if (size < obj->hdrlen) {
160 			err = got_error(GOT_ERR_BAD_OBJ_HDR);
161 			goto done;
162 		}
163 
164 		err = got_privsep_send_blob(&ibuf, size, obj->hdrlen, buf);
165 done:
166 		free(buf);
167 		if (f) {
168 			if (fclose(f) != 0 && err == NULL)
169 				err = got_error_from_errno("fclose");
170 		} else if (imsg.fd != -1) {
171 			if (close(imsg.fd) != 0 && err == NULL)
172 				err = got_error_from_errno("close");
173 		}
174 		if (imsg_outfd.fd != -1) {
175 			if (close(imsg_outfd.fd) != 0 && err == NULL)
176 				err = got_error_from_errno("close");
177 		}
178 
179 		imsg_free(&imsg);
180 		imsg_free(&imsg_outfd);
181 		if (obj)
182 			got_object_close(obj);
183 		if (err)
184 			break;
185 	}
186 
187 	imsg_clear(&ibuf);
188 	if (err) {
189 		if (!sigint_received && err->code != GOT_ERR_PRIVSEP_PIPE) {
190 			fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
191 			got_privsep_send_error(&ibuf, err);
192 		}
193 	}
194 	if (close(GOT_IMSG_FD_CHILD) != 0 && err == NULL)
195 		err = got_error_from_errno("close");
196 	return err ? 1 : 0;
197 }