1 /*
2  * Copyright (c) 2022 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/queue.h>
18 #include <sys/types.h>
19 #include <sys/uio.h>
20 
21 #include <errno.h>
22 #include <event.h>
23 #include <imsg.h>
24 #include <limits.h>
25 #include <poll.h>
26 #include <sha1.h>
27 #include <sha2.h>
28 #include <stdio.h>
29 #include <string.h>
30 #include <unistd.h>
31 
32 #include "got_error.h"
33 #include "got_object.h"
34 #include "got_path.h"
35 
36 #include "got_lib_poll.h"
37 
38 #include "gotd.h"
39 
40 const struct got_error *
41 gotd_imsg_recv_error(uint32_t *client_id, struct imsg *imsg)
42 {
43 	struct gotd_imsg_error ierr;
44 	size_t datalen;
45 
46 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
47 	if (datalen != sizeof(ierr))
48 		return got_error(GOT_ERR_PRIVSEP_LEN);
49 	memcpy(&ierr, imsg->data, sizeof(ierr));
50 
51 	if (client_id)
52 		*client_id = ierr.client_id;
53 
54 	if (ierr.code == GOT_ERR_ERRNO)
55 		errno = ierr.errno_code;
56 
57 	return got_error_msg(ierr.code, ierr.msg);
58 }
59 
60 const struct got_error *
61 gotd_imsg_flush(struct imsgbuf *ibuf)
62 {
63 	const struct got_error *err = NULL;
64 
65 	while (ibuf->w.queued > 0) {
66 		err = got_poll_fd(ibuf->fd, POLLOUT, INFTIM);
67 		if (err)
68 			break;
69 
70 		if (imsg_flush(ibuf) == -1) {
71 			if (errno != EAGAIN) {
72 				imsg_clear(ibuf);
73 				err = got_error_from_errno("imsg_flush");
74 				break;
75 			}
76 		}
77 	}
78 
79 	return err;
80 }
81 
82 const struct got_error *
83 gotd_imsg_recv(struct imsg *imsg, struct imsgbuf *ibuf, size_t min_datalen)
84 {
85 	ssize_t n;
86 
87 	n = imsg_get(ibuf, imsg);
88 	if (n == -1)
89 		return got_error_from_errno("imsg_get");
90 
91 	if (n == 0) {
92 		n = imsg_read(ibuf);
93 		if (n == -1) {
94 			if (errno == EAGAIN)
95 				return got_error(GOT_ERR_PRIVSEP_READ);
96 			return got_error_from_errno("imsg_read");
97 		}
98 		if (n == 0)
99 			return got_error(GOT_ERR_EOF);
100 		n = imsg_get(ibuf, imsg);
101 		if (n == -1)
102 			return got_error_from_errno("imsg_get");
103 	}
104 
105 	if (imsg->hdr.len < IMSG_HEADER_SIZE + min_datalen)
106 		return got_error(GOT_ERR_PRIVSEP_LEN);
107 
108 	return NULL;
109 }
110 
111 const struct got_error *
112 gotd_imsg_poll_recv(struct imsg *imsg, struct imsgbuf *ibuf, size_t min_datalen)
113 {
114 	const struct got_error *err = NULL;
115 
116 	for (;;) {
117 		err = gotd_imsg_recv(imsg, ibuf, min_datalen);
118 		if (err == NULL || err->code != GOT_ERR_PRIVSEP_READ)
119 			return err;
120 
121 		err = got_poll_fd(ibuf->fd, POLLIN, INFTIM);
122 		if (err)
123 			break;
124 	}
125 
126 	return err;
127 }
128 
129 int
130 gotd_imsg_send_error(struct imsgbuf *ibuf, uint32_t peerid,
131     uint32_t client_id, const struct got_error *err)
132 {
133 	const struct got_error *flush_err;
134 	struct gotd_imsg_error ierr;
135 	int ret;
136 
137 	ierr.code = err->code;
138 	if (err->code == GOT_ERR_ERRNO)
139 		ierr.errno_code = errno;
140 	else
141 		ierr.errno_code = 0;
142 	ierr.client_id = client_id;
143 	strlcpy(ierr.msg, err->msg, sizeof(ierr.msg));
144 
145 	ret = imsg_compose(ibuf, GOTD_IMSG_ERROR, peerid, getpid(), -1,
146 	    &ierr, sizeof(ierr));
147 	if (ret == -1)
148 		return -1;
149 
150 	flush_err = gotd_imsg_flush(ibuf);
151 	if (flush_err)
152 		return -1;
153 
154 	return 0;
155 }
156 
157 int
158 gotd_imsg_send_error_event(struct gotd_imsgev *iev, uint32_t peerid,
159     uint32_t client_id, const struct got_error *err)
160 {
161 	struct gotd_imsg_error ierr;
162 	int ret;
163 
164 	ierr.code = err->code;
165 	if (err->code == GOT_ERR_ERRNO)
166 		ierr.errno_code = errno;
167 	else
168 		ierr.errno_code = 0;
169 	ierr.client_id = client_id;
170 	strlcpy(ierr.msg, err->msg, sizeof(ierr.msg));
171 
172 	ret = gotd_imsg_compose_event(iev, GOTD_IMSG_ERROR, peerid, -1,
173 	    &ierr, sizeof(ierr));
174 	if (ret == -1)
175 		return -1;
176 
177 	return 0;
178 }
179 
180 void
181 gotd_imsg_event_add(struct gotd_imsgev *iev)
182 {
183 	iev->events = EV_READ;
184 	if (iev->ibuf.w.queued)
185 		iev->events |= EV_WRITE;
186 
187 	event_del(&iev->ev);
188 	event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev);
189 	event_add(&iev->ev, NULL);
190 }
191 
192 int
193 gotd_imsg_compose_event(struct gotd_imsgev *iev, uint16_t type, uint32_t peerid,
194     int fd, void *data, uint16_t datalen)
195 {
196 	int ret;
197 
198 	ret = imsg_compose(&iev->ibuf, type, peerid, getpid(), fd,
199 	    data, datalen);
200 	if (ret != -1)
201 		gotd_imsg_event_add(iev);
202 
203 	return ret;
204 }
205 
206 int
207 gotd_imsg_forward(struct gotd_imsgev *iev, struct imsg *imsg, int fd)
208 {
209 	return gotd_imsg_compose_event(iev, imsg->hdr.type, imsg->hdr.peerid,
210 	    fd, imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE);
211 }