1 /*
2  * Copyright (c) 2018, 2019, 2020 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 <limits.h>
24 #include <signal.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <unistd.h>
29 #include <zlib.h>
30 
31 #include "got_compat.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_object_qid.h"
41 #include "got_lib_privsep.h"
42 #include "got_lib_hash.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 
71 	/* revoke fs access */
72 	if (landlock_no_fs() == -1) {
73 		err = got_error_from_errno("landlock_no_fs");
74 		got_privsep_send_error(&ibuf, err);
75 		return 1;
76 	}
77 	if (cap_enter() == -1) {
78 		err = got_error_from_errno("cap_enter");
79 		got_privsep_send_error(&ibuf, err);
80 		return 1;
81 	}
82 #endif
83 
84 	for (;;) {
85 		struct imsg imsg;
86 		struct got_commit_object *commit = NULL;
87 		struct got_object_id expected_id;
88 
89 		if (sigint_received) {
90 			err = got_error(GOT_ERR_CANCELLED);
91 			break;
92 		}
93 
94 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
95 		if (err) {
96 			if (err->code == GOT_ERR_PRIVSEP_PIPE)
97 				err = NULL;
98 			break;
99 		}
100 
101 		if (imsg.hdr.type == GOT_IMSG_STOP)
102 			break;
103 
104 		if (imsg.hdr.type != GOT_IMSG_COMMIT_REQUEST) {
105 			err = got_error(GOT_ERR_PRIVSEP_MSG);
106 			goto done;
107 		}
108 
109 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
110 		if (datalen != sizeof(expected_id)) {
111 			err = got_error(GOT_ERR_PRIVSEP_LEN);
112 			goto done;
113 		}
114 		memcpy(&expected_id, imsg.data, sizeof(expected_id));
115 
116 		if (imsg.fd == -1) {
117 			err = got_error(GOT_ERR_PRIVSEP_NO_FD);
118 			goto done;
119 		}
120 
121 		err = got_object_read_commit(&commit, imsg.fd, &expected_id, 0);
122 		if (err)
123 			goto done;
124 
125 		err = got_privsep_send_commit(&ibuf, commit);
126 		got_object_commit_close(commit);
127 done:
128 		if (imsg.fd != -1 && close(imsg.fd) == -1 && err == NULL)
129 			err = got_error_from_errno("close");
130 		imsg_free(&imsg);
131 		if (err)
132 			break;
133 	}
134 
135 	imsg_clear(&ibuf);
136 	if (err) {
137 		if (!sigint_received && err->code != GOT_ERR_PRIVSEP_PIPE) {
138 			fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
139 			got_privsep_send_error(&ibuf, err);
140 		}
141 	}
142 	if (close(GOT_IMSG_FD_CHILD) == -1 && err == NULL)
143 		err = got_error_from_errno("close");
144 	return err ? 1 : 0;
145 }