1 /*	$OpenBSD: imsg.c,v 1.11 2005/04/26 15:18:22 henning Exp $ */
2 
3 /*
4  * Copyright © 2013
5  *	Thorsten “mirabilos” Glaser <tg@mirbsd.org>
6  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
7  *
8  * Permission to use, copy, modify, and distribute this software for any
9  * purpose with or without fee is hereby granted, provided that the above
10  * copyright notice and this permission notice appear in all copies.
11  *
12  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
13  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
14  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
15  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
16  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
17  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
18  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19  */
20 
21 #include <sys/types.h>
22 
23 #include <errno.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <unistd.h>
27 
28 #include "ntpd.h"
29 
30 __RCSID("$MirOS: src/usr.sbin/ntpd/imsg.c,v 1.8 2013/10/31 20:07:28 tg Exp $");
31 
32 void
imsg_init(struct imsgbuf * ibuf,int fd)33 imsg_init(struct imsgbuf *ibuf, int fd)
34 {
35 	msgbuf_init(&ibuf->w);
36 	bzero(&ibuf->r, sizeof(ibuf->r));
37 	ibuf->fd = fd;
38 	ibuf->w.fd = fd;
39 	ibuf->pid = getpid();
40 }
41 
42 int
imsg_read(struct imsgbuf * ibuf)43 imsg_read(struct imsgbuf *ibuf)
44 {
45 	ssize_t			 n;
46 
47 	if ((n = read(ibuf->fd, ibuf->r.buf + ibuf->r.wpos,
48 	    sizeof(ibuf->r.buf) - ibuf->r.wpos)) == -1) {
49 		if (errno != EINTR && errno != EAGAIN) {
50 			log_warn("imsg_read: pipe read error");
51 			return (-1);
52 		}
53 		return (0);
54 	}
55 
56 	ibuf->r.wpos += n;
57 
58 	return (n);
59 }
60 
61 int
imsg_get(struct imsgbuf * ibuf,struct imsg * imsg)62 imsg_get(struct imsgbuf *ibuf, struct imsg *imsg)
63 {
64 	size_t			 av, left, datalen;
65 
66 	av = ibuf->r.wpos;
67 
68 	if (IMSG_HEADER_SIZE > av)
69 		return (0);
70 
71 	memcpy(&imsg->hdr, ibuf->r.buf, sizeof(imsg->hdr));
72 	if (imsg->hdr.len < IMSG_HEADER_SIZE ||
73 	    imsg->hdr.len > MAX_IMSGSIZE) {
74 		log_warnx("imsg_get: imsg hdr len %u out of bounds, type=%u",
75 		    imsg->hdr.len, imsg->hdr.type);
76 		return (-1);
77 	}
78 	if (imsg->hdr.len > av)
79 		return (0);
80 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
81 	ibuf->r.rptr = ibuf->r.buf + IMSG_HEADER_SIZE;
82 	if ((imsg->data = malloc(datalen)) == NULL) {
83 		log_warn("imsg_get");
84 		return (-1);
85 	}
86 	memcpy(imsg->data, ibuf->r.rptr, datalen);
87 
88 	if (imsg->hdr.len < av) {
89 		left = av - imsg->hdr.len;
90 		memmove(&ibuf->r.buf, ibuf->r.buf + imsg->hdr.len, left);
91 		ibuf->r.wpos = left;
92 	} else
93 		ibuf->r.wpos = 0;
94 
95 	return (datalen + IMSG_HEADER_SIZE);
96 }
97 
98 int
imsg_compose(struct imsgbuf * ibuf,enum imsg_type type,u_int32_t peerid,pid_t pid,void * data,u_int16_t datalen)99 imsg_compose(struct imsgbuf *ibuf, enum imsg_type type, u_int32_t peerid,
100     pid_t pid, void *data, u_int16_t datalen)
101 {
102 	struct buf	*wbuf;
103 	int		 n;
104 
105 	if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL)
106 		return (-1);
107 
108 	if (imsg_add(wbuf, data, datalen) == -1)
109 		return (-1);
110 
111 	if ((n = imsg_close(ibuf, wbuf)) < 0)
112 		return (-1);
113 
114 	return (n);
115 }
116 
117 struct buf *
imsg_create(struct imsgbuf * ibuf,enum imsg_type type,u_int32_t peerid,pid_t pid,u_int16_t datalen)118 imsg_create(struct imsgbuf *ibuf __attribute__((__unused__)), enum imsg_type type,
119     u_int32_t peerid, pid_t pid, u_int16_t datalen)
120 {
121 	struct buf	*wbuf;
122 	struct imsg_hdr	 hdr;
123 
124 	if (datalen > MAX_IMSGSIZE - IMSG_HEADER_SIZE) {
125 		log_warnx("imsg_create: len %zu > MAX_IMSGSIZE; "
126 		    "type %u peerid %u", datalen + IMSG_HEADER_SIZE,
127 		    type, peerid);
128 		return (NULL);
129 	}
130 
131 	hdr.len = datalen + IMSG_HEADER_SIZE;
132 	hdr.type = type;
133 	hdr.peerid = peerid;
134 	hdr.pid = pid;
135 	if ((wbuf = buf_open(hdr.len)) == NULL) {
136 		log_warn("imsg_create: buf_open");
137 		return (NULL);
138 	}
139 	if (imsg_add(wbuf, &hdr, sizeof(hdr)) == -1)
140 		return (NULL);
141 
142 	return (wbuf);
143 }
144 
145 int
imsg_add(struct buf * msg,void * data,u_int16_t datalen)146 imsg_add(struct buf *msg, void *data, u_int16_t datalen)
147 {
148 	if (datalen)
149 		if (buf_add(msg, data, datalen) == -1) {
150 			log_warnx("imsg_add: buf_add error");
151 			buf_free(msg);
152 			return (-1);
153 		}
154 	return (datalen);
155 }
156 
157 int
imsg_close(struct imsgbuf * ibuf,struct buf * msg)158 imsg_close(struct imsgbuf *ibuf, struct buf *msg)
159 {
160 	int	n;
161 
162 	if ((n = buf_close(&ibuf->w, msg)) < 0) {
163 			log_warnx("imsg_close: buf_close error");
164 			buf_free(msg);
165 			return (-1);
166 	}
167 	return (n);
168 }
169 
170 void
imsg_free(struct imsg * imsg)171 imsg_free(struct imsg *imsg)
172 {
173 	free(imsg->data);
174 }
175