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