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