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1 | /* $OpenBSD$ */ | |
2 | ||
3 | /* | |
4 | * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org> | |
5 | * | |
6 | * Permission to use, copy, modify, and distribute this software for any | |
7 | * purpose with or without fee is hereby granted, provided that the above | |
8 | * copyright notice and this permission notice appear in all copies. | |
9 | * | |
10 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES | |
11 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF | |
12 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR | |
13 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES | |
14 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN | |
15 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF | |
16 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | |
17 | */ | |
18 | ||
19 | #include <zebra.h> | |
20 | ||
21 | #include "queue.h" | |
22 | #include "imsg.h" | |
23 | ||
24 | int imsg_fd_overhead = 0; | |
25 | ||
26 | int imsg_get_fd(struct imsgbuf *); | |
27 | ||
28 | #ifndef __OpenBSD__ | |
29 | /* | |
30 | * The original code calls getdtablecount() which is OpenBSD specific. Use | |
31 | * available_fds() from OpenSMTPD instead. | |
32 | */ | |
33 | static int available_fds(unsigned int n) | |
34 | { | |
35 | unsigned int i; | |
36 | int ret, fds[256]; | |
37 | ||
38 | if (n > (sizeof(fds) / sizeof(fds[0]))) | |
39 | return (1); | |
40 | ||
41 | ret = 0; | |
42 | for (i = 0; i < n; i++) { | |
43 | fds[i] = -1; | |
44 | if ((fds[i] = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { | |
45 | if (errno == EAFNOSUPPORT || errno == EPROTONOSUPPORT) | |
46 | fds[i] = socket(AF_INET6, SOCK_DGRAM, 0); | |
47 | if (fds[i] < 0) { | |
48 | ret = 1; | |
49 | break; | |
50 | } | |
51 | } | |
52 | } | |
53 | ||
54 | for (i = 0; i < n && fds[i] >= 0; i++) | |
55 | close(fds[i]); | |
56 | ||
57 | return (ret); | |
58 | } | |
59 | #endif | |
60 | ||
61 | void imsg_init(struct imsgbuf *ibuf, int fd) | |
62 | { | |
63 | msgbuf_init(&ibuf->w); | |
64 | memset(&ibuf->r, 0, sizeof(ibuf->r)); | |
65 | ibuf->fd = fd; | |
66 | ibuf->w.fd = fd; | |
67 | ibuf->pid = getpid(); | |
68 | TAILQ_INIT(&ibuf->fds); | |
69 | } | |
70 | ||
71 | ssize_t imsg_read(struct imsgbuf *ibuf) | |
72 | { | |
73 | struct msghdr msg; | |
74 | struct cmsghdr *cmsg; | |
75 | union { | |
76 | struct cmsghdr hdr; | |
77 | char buf[CMSG_SPACE(sizeof(int) * 1)]; | |
78 | } cmsgbuf; | |
79 | struct iovec iov; | |
80 | ssize_t n; | |
81 | int fd; | |
82 | struct imsg_fd *ifd; | |
83 | ||
84 | memset(&msg, 0, sizeof(msg)); | |
85 | memset(&cmsgbuf, 0, sizeof(cmsgbuf)); | |
86 | ||
87 | iov.iov_base = ibuf->r.buf + ibuf->r.wpos; | |
88 | iov.iov_len = sizeof(ibuf->r.buf) - ibuf->r.wpos; | |
89 | msg.msg_iov = &iov; | |
90 | msg.msg_iovlen = 1; | |
91 | msg.msg_control = &cmsgbuf.buf; | |
92 | msg.msg_controllen = sizeof(cmsgbuf.buf); | |
93 | ||
94 | if ((ifd = calloc(1, sizeof(struct imsg_fd))) == NULL) | |
95 | return (-1); | |
96 | ||
97 | again: | |
98 | #ifdef __OpenBSD__ | |
99 | if (getdtablecount() + imsg_fd_overhead | |
100 | + (int)((CMSG_SPACE(sizeof(int)) - CMSG_SPACE(0)) | |
101 | / sizeof(int)) | |
102 | >= getdtablesize()) { | |
103 | #else | |
104 | if (available_fds(imsg_fd_overhead | |
105 | + (CMSG_SPACE(sizeof(int)) - CMSG_SPACE(0)) | |
106 | / sizeof(int))) { | |
107 | #endif | |
108 | errno = EAGAIN; | |
109 | free(ifd); | |
110 | return (-1); | |
111 | } | |
112 | ||
113 | n = recvmsg(ibuf->fd, &msg, 0); | |
114 | if (n == -1) { | |
115 | if (errno == EINTR) | |
116 | goto again; | |
117 | goto fail; | |
118 | } | |
119 | ||
120 | ibuf->r.wpos += n; | |
121 | ||
122 | for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; | |
123 | cmsg = CMSG_NXTHDR(&msg, cmsg)) { | |
124 | if (cmsg->cmsg_level == SOL_SOCKET | |
125 | && cmsg->cmsg_type == SCM_RIGHTS) { | |
126 | int i; | |
127 | int j; | |
128 | ||
129 | /* | |
130 | * We only accept one file descriptor. Due to C | |
131 | * padding rules, our control buffer might contain | |
132 | * more than one fd, and we must close them. | |
133 | */ | |
134 | j = ((char *)cmsg + cmsg->cmsg_len | |
135 | - (char *)CMSG_DATA(cmsg)) | |
136 | / sizeof(int); | |
137 | for (i = 0; i < j; i++) { | |
138 | fd = ((int *)CMSG_DATA(cmsg))[i]; | |
139 | if (ifd != NULL) { | |
140 | ifd->fd = fd; | |
141 | TAILQ_INSERT_TAIL(&ibuf->fds, ifd, | |
142 | entry); | |
143 | ifd = NULL; | |
144 | } else | |
145 | close(fd); | |
146 | } | |
147 | } | |
148 | /* we do not handle other ctl data level */ | |
149 | } | |
150 | ||
151 | fail: | |
152 | free(ifd); | |
153 | return (n); | |
154 | } | |
155 | ||
156 | ssize_t imsg_get(struct imsgbuf *ibuf, struct imsg *imsg) | |
157 | { | |
158 | size_t av, left, datalen; | |
159 | ||
160 | av = ibuf->r.wpos; | |
161 | ||
162 | if (IMSG_HEADER_SIZE > av) | |
163 | return (0); | |
164 | ||
165 | memcpy(&imsg->hdr, ibuf->r.buf, sizeof(imsg->hdr)); | |
166 | if (imsg->hdr.len < IMSG_HEADER_SIZE || imsg->hdr.len > MAX_IMSGSIZE) { | |
167 | errno = ERANGE; | |
168 | return (-1); | |
169 | } | |
170 | if (imsg->hdr.len > av) | |
171 | return (0); | |
172 | datalen = imsg->hdr.len - IMSG_HEADER_SIZE; | |
173 | ibuf->r.rptr = ibuf->r.buf + IMSG_HEADER_SIZE; | |
174 | if (datalen == 0) | |
175 | imsg->data = NULL; | |
176 | else if ((imsg->data = malloc(datalen)) == NULL) | |
177 | return (-1); | |
178 | ||
179 | if (imsg->hdr.flags & IMSGF_HASFD) | |
180 | imsg->fd = imsg_get_fd(ibuf); | |
181 | else | |
182 | imsg->fd = -1; | |
183 | ||
184 | if (imsg->data) | |
185 | memcpy(imsg->data, ibuf->r.rptr, datalen); | |
186 | ||
187 | if (imsg->hdr.len < av) { | |
188 | left = av - imsg->hdr.len; | |
189 | memmove(&ibuf->r.buf, ibuf->r.buf + imsg->hdr.len, left); | |
190 | ibuf->r.wpos = left; | |
191 | } else | |
192 | ibuf->r.wpos = 0; | |
193 | ||
194 | return (datalen + IMSG_HEADER_SIZE); | |
195 | } | |
196 | ||
197 | int imsg_compose(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid, | |
198 | pid_t pid, int fd, const void *data, uint16_t datalen) | |
199 | { | |
200 | struct ibuf *wbuf; | |
201 | ||
202 | if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL) | |
203 | return (-1); | |
204 | ||
205 | if (imsg_add(wbuf, data, datalen) == -1) | |
206 | return (-1); | |
207 | ||
208 | wbuf->fd = fd; | |
209 | ||
210 | imsg_close(ibuf, wbuf); | |
211 | ||
212 | return (1); | |
213 | } | |
214 | ||
215 | int imsg_composev(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid, | |
216 | pid_t pid, int fd, const struct iovec *iov, int iovcnt) | |
217 | { | |
218 | struct ibuf *wbuf; | |
219 | int i, datalen = 0; | |
220 | ||
221 | for (i = 0; i < iovcnt; i++) | |
222 | datalen += iov[i].iov_len; | |
223 | ||
224 | if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL) | |
225 | return (-1); | |
226 | ||
227 | for (i = 0; i < iovcnt; i++) | |
228 | if (imsg_add(wbuf, iov[i].iov_base, iov[i].iov_len) == -1) | |
229 | return (-1); | |
230 | ||
231 | wbuf->fd = fd; | |
232 | ||
233 | imsg_close(ibuf, wbuf); | |
234 | ||
235 | return (1); | |
236 | } | |
237 | ||
238 | /* ARGSUSED */ | |
239 | struct ibuf *imsg_create(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid, | |
240 | pid_t pid, uint16_t datalen) | |
241 | { | |
242 | struct ibuf *wbuf; | |
243 | struct imsg_hdr hdr; | |
244 | ||
245 | memset(&hdr, 0x00, IMSG_HEADER_SIZE); | |
246 | ||
247 | datalen += IMSG_HEADER_SIZE; | |
248 | if (datalen > MAX_IMSGSIZE) { | |
249 | errno = ERANGE; | |
250 | return (NULL); | |
251 | } | |
252 | ||
253 | hdr.type = type; | |
254 | hdr.flags = 0; | |
255 | hdr.peerid = peerid; | |
256 | if ((hdr.pid = pid) == 0) | |
257 | hdr.pid = ibuf->pid; | |
258 | if ((wbuf = ibuf_dynamic(datalen, MAX_IMSGSIZE)) == NULL) { | |
259 | return (NULL); | |
260 | } | |
261 | if (imsg_add(wbuf, &hdr, sizeof(hdr)) == -1) | |
262 | return (NULL); | |
263 | ||
264 | return (wbuf); | |
265 | } | |
266 | ||
267 | int imsg_add(struct ibuf *msg, const void *data, uint16_t datalen) | |
268 | { | |
269 | if (datalen) | |
270 | if (ibuf_add(msg, data, datalen) == -1) { | |
271 | ibuf_free(msg); | |
272 | return (-1); | |
273 | } | |
274 | return (datalen); | |
275 | } | |
276 | ||
277 | void imsg_close(struct imsgbuf *ibuf, struct ibuf *msg) | |
278 | { | |
279 | struct imsg_hdr *hdr; | |
280 | ||
281 | hdr = (struct imsg_hdr *)msg->buf; | |
282 | ||
283 | hdr->flags &= ~IMSGF_HASFD; | |
284 | if (msg->fd != -1) | |
285 | hdr->flags |= IMSGF_HASFD; | |
286 | ||
287 | hdr->len = (uint16_t)msg->wpos; | |
288 | ||
289 | ibuf_close(&ibuf->w, msg); | |
290 | } | |
291 | ||
292 | void imsg_free(struct imsg *imsg) | |
293 | { | |
294 | free(imsg->data); | |
295 | } | |
296 | ||
297 | int imsg_get_fd(struct imsgbuf *ibuf) | |
298 | { | |
299 | int fd; | |
300 | struct imsg_fd *ifd; | |
301 | ||
302 | if ((ifd = TAILQ_POP_FIRST(&ibuf->fds, entry)) == NULL) | |
303 | return (-1); | |
304 | ||
305 | fd = ifd->fd; | |
306 | free(ifd); | |
307 | ||
308 | return (fd); | |
309 | } | |
310 | ||
311 | int imsg_flush(struct imsgbuf *ibuf) | |
312 | { | |
313 | while (ibuf->w.queued) | |
314 | if (msgbuf_write(&ibuf->w) <= 0) | |
315 | return (-1); | |
316 | return (0); | |
317 | } | |
318 | ||
319 | void imsg_clear(struct imsgbuf *ibuf) | |
320 | { | |
321 | int fd; | |
322 | ||
323 | msgbuf_clear(&ibuf->w); | |
324 | while ((fd = imsg_get_fd(ibuf)) != -1) | |
325 | close(fd); | |
326 | } |