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