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