]>
Commit | Line | Data |
---|---|---|
1 | // SPDX-License-Identifier: ISC | |
2 | /* $OpenBSD$ */ | |
3 | ||
4 | /* | |
5 | * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org> | |
6 | */ | |
7 | ||
8 | #include <zebra.h> | |
9 | ||
10 | #include "memory.h" | |
11 | #include "queue.h" | |
12 | #include "imsg.h" | |
13 | ||
14 | static int imsg_fd_overhead = 0; | |
15 | ||
16 | static int imsg_get_fd(struct imsgbuf *); | |
17 | ||
18 | #ifndef __OpenBSD__ | |
19 | /* | |
20 | * The original code calls getdtablecount() which is OpenBSD specific. Use | |
21 | * available_fds() from OpenSMTPD instead. | |
22 | */ | |
23 | static int available_fds(unsigned int n) | |
24 | { | |
25 | unsigned int i; | |
26 | int ret, fds[256]; | |
27 | ||
28 | if (n > (unsigned int)array_size(fds)) | |
29 | return 1; | |
30 | ||
31 | ret = 0; | |
32 | for (i = 0; i < n; i++) { | |
33 | fds[i] = -1; | |
34 | if ((fds[i] = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { | |
35 | if (errno == EAFNOSUPPORT || errno == EPROTONOSUPPORT) | |
36 | fds[i] = socket(AF_INET6, SOCK_DGRAM, 0); | |
37 | if (fds[i] < 0) { | |
38 | ret = 1; | |
39 | break; | |
40 | } | |
41 | } | |
42 | } | |
43 | ||
44 | for (i = 0; i < n && fds[i] >= 0; i++) | |
45 | close(fds[i]); | |
46 | ||
47 | return (ret); | |
48 | } | |
49 | #endif | |
50 | ||
51 | void imsg_init(struct imsgbuf *ibuf, int fd) | |
52 | { | |
53 | msgbuf_init(&ibuf->w); | |
54 | memset(&ibuf->r, 0, sizeof(ibuf->r)); | |
55 | ibuf->fd = fd; | |
56 | ibuf->w.fd = fd; | |
57 | ibuf->pid = getpid(); | |
58 | TAILQ_INIT(&ibuf->fds); | |
59 | } | |
60 | ||
61 | ssize_t imsg_read(struct imsgbuf *ibuf) | |
62 | { | |
63 | struct msghdr msg; | |
64 | struct cmsghdr *cmsg; | |
65 | union { | |
66 | struct cmsghdr hdr; | |
67 | char buf[CMSG_SPACE(sizeof(int) * 1)]; | |
68 | } cmsgbuf; | |
69 | struct iovec iov; | |
70 | ssize_t n; | |
71 | int fd; | |
72 | struct imsg_fd *ifd; | |
73 | ||
74 | memset(&msg, 0, sizeof(msg)); | |
75 | memset(&cmsgbuf, 0, sizeof(cmsgbuf)); | |
76 | ||
77 | iov.iov_base = ibuf->r.buf + ibuf->r.wpos; | |
78 | iov.iov_len = sizeof(ibuf->r.buf) - ibuf->r.wpos; | |
79 | msg.msg_iov = &iov; | |
80 | msg.msg_iovlen = 1; | |
81 | msg.msg_control = &cmsgbuf.buf; | |
82 | msg.msg_controllen = sizeof(cmsgbuf.buf); | |
83 | ||
84 | if ((ifd = calloc(1, sizeof(struct imsg_fd))) == NULL) | |
85 | return -1; | |
86 | ||
87 | again: | |
88 | #ifdef __OpenBSD__ | |
89 | if (getdtablecount() + imsg_fd_overhead | |
90 | + (int)((CMSG_SPACE(sizeof(int)) - CMSG_SPACE(0)) | |
91 | / sizeof(int)) | |
92 | >= getdtablesize()) { | |
93 | #else | |
94 | if (available_fds(imsg_fd_overhead | |
95 | + (CMSG_SPACE(sizeof(int)) - CMSG_SPACE(0)) | |
96 | / sizeof(int))) { | |
97 | #endif | |
98 | errno = EAGAIN; | |
99 | free(ifd); | |
100 | return -1; | |
101 | } | |
102 | ||
103 | n = recvmsg(ibuf->fd, &msg, 0); | |
104 | if (n == -1) { | |
105 | if (errno == EINTR) | |
106 | goto again; | |
107 | goto fail; | |
108 | } | |
109 | ||
110 | ibuf->r.wpos += n; | |
111 | ||
112 | for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; | |
113 | cmsg = CMSG_NXTHDR(&msg, cmsg)) { | |
114 | if (cmsg->cmsg_level == SOL_SOCKET | |
115 | && cmsg->cmsg_type == SCM_RIGHTS) { | |
116 | int i; | |
117 | int j; | |
118 | ||
119 | /* | |
120 | * We only accept one file descriptor. Due to C | |
121 | * padding rules, our control buffer might contain | |
122 | * more than one fd, and we must close them. | |
123 | */ | |
124 | j = ((char *)cmsg + cmsg->cmsg_len | |
125 | - (char *)CMSG_DATA(cmsg)) | |
126 | / sizeof(int); | |
127 | for (i = 0; i < j; i++) { | |
128 | fd = ((int *)CMSG_DATA(cmsg))[i]; | |
129 | if (ifd != NULL) { | |
130 | ifd->fd = fd; | |
131 | TAILQ_INSERT_TAIL(&ibuf->fds, ifd, | |
132 | entry); | |
133 | ifd = NULL; | |
134 | } else | |
135 | close(fd); | |
136 | } | |
137 | } | |
138 | /* we do not handle other ctl data level */ | |
139 | } | |
140 | ||
141 | fail: | |
142 | free(ifd); | |
143 | return (n); | |
144 | } | |
145 | ||
146 | ssize_t imsg_get(struct imsgbuf *ibuf, struct imsg *imsg) | |
147 | { | |
148 | size_t av, left, datalen; | |
149 | ||
150 | av = ibuf->r.wpos; | |
151 | ||
152 | if (IMSG_HEADER_SIZE > av) | |
153 | return 0; | |
154 | ||
155 | memcpy(&imsg->hdr, ibuf->r.buf, sizeof(imsg->hdr)); | |
156 | if (imsg->hdr.len < IMSG_HEADER_SIZE || imsg->hdr.len > MAX_IMSGSIZE) { | |
157 | errno = ERANGE; | |
158 | return -1; | |
159 | } | |
160 | if (imsg->hdr.len > av) | |
161 | return 0; | |
162 | datalen = imsg->hdr.len - IMSG_HEADER_SIZE; | |
163 | ibuf->r.rptr = ibuf->r.buf + IMSG_HEADER_SIZE; | |
164 | if (datalen == 0) | |
165 | imsg->data = NULL; | |
166 | else if ((imsg->data = malloc(datalen)) == NULL) | |
167 | return -1; | |
168 | ||
169 | if (imsg->hdr.flags & IMSGF_HASFD) | |
170 | imsg->fd = imsg_get_fd(ibuf); | |
171 | else | |
172 | imsg->fd = -1; | |
173 | ||
174 | if (imsg->data) | |
175 | memcpy(imsg->data, ibuf->r.rptr, datalen); | |
176 | ||
177 | if (imsg->hdr.len < av) { | |
178 | left = av - imsg->hdr.len; | |
179 | memmove(&ibuf->r.buf, ibuf->r.buf + imsg->hdr.len, left); | |
180 | ibuf->r.wpos = left; | |
181 | } else | |
182 | ibuf->r.wpos = 0; | |
183 | ||
184 | return (datalen + IMSG_HEADER_SIZE); | |
185 | } | |
186 | ||
187 | int imsg_compose(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid, | |
188 | pid_t pid, int fd, const void *data, uint16_t datalen) | |
189 | { | |
190 | struct ibuf *wbuf; | |
191 | ||
192 | if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL) | |
193 | return -1; | |
194 | ||
195 | if (imsg_add(wbuf, data, datalen) == -1) | |
196 | return -1; | |
197 | ||
198 | wbuf->fd = fd; | |
199 | ||
200 | imsg_close(ibuf, wbuf); | |
201 | ||
202 | return 1; | |
203 | } | |
204 | ||
205 | int imsg_composev(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid, | |
206 | pid_t pid, int fd, const struct iovec *iov, int iovcnt) | |
207 | { | |
208 | struct ibuf *wbuf; | |
209 | int i, datalen = 0; | |
210 | ||
211 | for (i = 0; i < iovcnt; i++) | |
212 | datalen += iov[i].iov_len; | |
213 | ||
214 | if ((wbuf = imsg_create(ibuf, type, peerid, pid, datalen)) == NULL) | |
215 | return -1; | |
216 | ||
217 | for (i = 0; i < iovcnt; i++) | |
218 | if (imsg_add(wbuf, iov[i].iov_base, iov[i].iov_len) == -1) | |
219 | return -1; | |
220 | ||
221 | wbuf->fd = fd; | |
222 | ||
223 | imsg_close(ibuf, wbuf); | |
224 | ||
225 | return 1; | |
226 | } | |
227 | ||
228 | /* ARGSUSED */ | |
229 | struct ibuf *imsg_create(struct imsgbuf *ibuf, uint32_t type, uint32_t peerid, | |
230 | pid_t pid, uint16_t datalen) | |
231 | { | |
232 | struct ibuf *wbuf; | |
233 | struct imsg_hdr hdr; | |
234 | ||
235 | memset(&hdr, 0x00, IMSG_HEADER_SIZE); | |
236 | ||
237 | datalen += IMSG_HEADER_SIZE; | |
238 | if (datalen > MAX_IMSGSIZE) { | |
239 | errno = ERANGE; | |
240 | return NULL; | |
241 | } | |
242 | ||
243 | hdr.type = type; | |
244 | hdr.flags = 0; | |
245 | hdr.peerid = peerid; | |
246 | if ((hdr.pid = pid) == 0) | |
247 | hdr.pid = ibuf->pid; | |
248 | if ((wbuf = ibuf_dynamic(datalen, MAX_IMSGSIZE)) == NULL) { | |
249 | return NULL; | |
250 | } | |
251 | if (imsg_add(wbuf, &hdr, sizeof(hdr)) == -1) | |
252 | return NULL; | |
253 | ||
254 | return (wbuf); | |
255 | } | |
256 | ||
257 | int imsg_add(struct ibuf *msg, const void *data, uint16_t datalen) | |
258 | { | |
259 | if (datalen) | |
260 | if (ibuf_add(msg, data, datalen) == -1) { | |
261 | ibuf_free(msg); | |
262 | return -1; | |
263 | } | |
264 | return (datalen); | |
265 | } | |
266 | ||
267 | void imsg_close(struct imsgbuf *ibuf, struct ibuf *msg) | |
268 | { | |
269 | struct imsg_hdr *hdr; | |
270 | ||
271 | hdr = (struct imsg_hdr *)msg->buf; | |
272 | ||
273 | hdr->flags &= ~IMSGF_HASFD; | |
274 | if (msg->fd != -1) | |
275 | hdr->flags |= IMSGF_HASFD; | |
276 | ||
277 | hdr->len = (uint16_t)msg->wpos; | |
278 | ||
279 | ibuf_close(&ibuf->w, msg); | |
280 | } | |
281 | ||
282 | void imsg_free(struct imsg *imsg) | |
283 | { | |
284 | free(imsg->data); | |
285 | } | |
286 | ||
287 | int imsg_get_fd(struct imsgbuf *ibuf) | |
288 | { | |
289 | int fd; | |
290 | struct imsg_fd *ifd; | |
291 | ||
292 | if ((ifd = TAILQ_POP_FIRST(&ibuf->fds, entry)) == NULL) | |
293 | return -1; | |
294 | ||
295 | fd = ifd->fd; | |
296 | free(ifd); | |
297 | ||
298 | return (fd); | |
299 | } | |
300 | ||
301 | int imsg_flush(struct imsgbuf *ibuf) | |
302 | { | |
303 | while (ibuf->w.queued) | |
304 | if (msgbuf_write(&ibuf->w) <= 0) | |
305 | return -1; | |
306 | return 0; | |
307 | } | |
308 | ||
309 | void imsg_clear(struct imsgbuf *ibuf) | |
310 | { | |
311 | int fd; | |
312 | ||
313 | msgbuf_clear(&ibuf->w); | |
314 | while ((fd = imsg_get_fd(ibuf)) != -1) | |
315 | close(fd); | |
316 | } |