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