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 #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 static const struct got_error *
52 read_tag_object(struct got_tag_object **tag, FILE *f)
53 {
54 	const struct got_error *err = NULL;
55 	struct got_object *obj;
56 	size_t len;
57 	uint8_t *p;
58 
59 	err = got_inflate_to_mem(&p, &len, NULL, f);
60 	if (err)
61 		return err;
62 
63 	err = got_object_parse_header(&obj, p, len);
64 	if (err)
65 		return err;
66 
67 	if (len < obj->hdrlen + obj->size) {
68 		err = got_error(GOT_ERR_BAD_OBJ_DATA);
69 		goto done;
70 	}
71 
72 	/* Skip object header. */
73 	len -= obj->hdrlen;
74 	err = got_object_parse_tag(tag, p + obj->hdrlen, len);
75 done:
76 	free(p);
77 	got_object_close(obj);
78 	return err;
79 }
80 
81 int
82 main(int argc, char *argv[])
83 {
84 	const struct got_error *err = NULL;
85 	struct imsgbuf ibuf;
86 
87 	signal(SIGINT, catch_sigint);
88 
89 	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
90 
91 #ifndef PROFILE
92 	/* revoke access to most system calls */
93 	if (pledge("stdio recvfd", NULL) == -1) {
94 		err = got_error_from_errno("pledge");
95 		got_privsep_send_error(&ibuf, err);
96 		return 1;
97 	}
98 #endif
99 
100 	for (;;) {
101 		struct imsg imsg;
102 		FILE *f = NULL;
103 		struct got_tag_object *tag = NULL;
104 
105 		if (sigint_received) {
106 			err = got_error(GOT_ERR_CANCELLED);
107 			break;
108 		}
109 
110 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
111 		if (err) {
112 			if (err->code == GOT_ERR_PRIVSEP_PIPE)
113 				err = NULL;
114 			break;
115 		}
116 
117 		if (imsg.hdr.type == GOT_IMSG_STOP)
118 			break;
119 
120 		if (imsg.hdr.type != GOT_IMSG_TAG_REQUEST) {
121 			err = got_error(GOT_ERR_PRIVSEP_MSG);
122 			goto done;
123 		}
124 
125 		if (imsg.fd == -1) {
126 			err = got_error(GOT_ERR_PRIVSEP_NO_FD);
127 			goto done;
128 		}
129 
130 		/* Always assume file offset zero. */
131 		f = fdopen(imsg.fd, "rb");
132 		if (f == NULL) {
133 			err = got_error_from_errno("fdopen");
134 			goto done;
135 		}
136 
137 		err = read_tag_object(&tag, f);
138 		if (err)
139 			goto done;
140 
141 		err = got_privsep_send_tag(&ibuf, tag);
142 done:
143 		if (f) {
144 			if (fclose(f) != 0 && err == NULL)
145 				err = got_error_from_errno("fclose");
146 		} else if (imsg.fd != -1) {
147 			if (close(imsg.fd) != 0 && err == NULL)
148 				err = got_error_from_errno("close");
149 		}
150 		imsg_free(&imsg);
151 		if (err)
152 			break;
153 	}
154 
155 	imsg_clear(&ibuf);
156 	if (err) {
157 		if (!sigint_received && err->code != GOT_ERR_PRIVSEP_PIPE) {
158 			fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
159 			got_privsep_send_error(&ibuf, err);
160 		}
161 	}
162 	if (close(GOT_IMSG_FD_CHILD) != 0 && err == NULL)
163 		err = got_error_from_errno("close");
164 	return err ? 1 : 0;
165 }