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 		int fd = -1;
89 
90 		if (sigint_received) {
91 			err = got_error(GOT_ERR_CANCELLED);
92 			break;
93 		}
94 
95 		err = got_privsep_recv_imsg(&imsg, &ibuf, 0);
96 		if (err) {
97 			if (err->code == GOT_ERR_PRIVSEP_PIPE)
98 				err = NULL;
99 			break;
100 		}
101 
102 		if (imsg.hdr.type == GOT_IMSG_STOP)
103 			break;
104 
105 		if (imsg.hdr.type != GOT_IMSG_COMMIT_REQUEST) {
106 			err = got_error(GOT_ERR_PRIVSEP_MSG);
107 			goto done;
108 		}
109 
110 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
111 		if (datalen != sizeof(expected_id)) {
112 			err = got_error(GOT_ERR_PRIVSEP_LEN);
113 			goto done;
114 		}
115 		memcpy(&expected_id, imsg.data, sizeof(expected_id));
116 
117 		fd = imsg_get_fd(&imsg);
118 		if (fd == -1) {
119 			err = got_error(GOT_ERR_PRIVSEP_NO_FD);
120 			goto done;
121 		}
122 
123 		err = got_object_read_commit(&commit, fd, &expected_id, 0);
124 		if (err)
125 			goto done;
126 
127 		err = got_privsep_send_commit(&ibuf, commit);
128 		got_object_commit_close(commit);
129 done:
130 		if (fd != -1 && close(fd) == -1 && err == NULL)
131 			err = got_error_from_errno("close");
132 		imsg_free(&imsg);
133 		if (err)
134 			break;
135 	}
136 
137 	imsg_clear(&ibuf);
138 	if (err) {
139 		if (!sigint_received && err->code != GOT_ERR_PRIVSEP_PIPE) {
140 			fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
141 			got_privsep_send_error(&ibuf, err);
142 		}
143 	}
144 	if (close(GOT_IMSG_FD_CHILD) == -1 && err == NULL)
145 		err = got_error_from_errno("close");
146 	return err ? 1 : 0;
147 }