Annotation of embedaddon/sudo/common/event_select.c, revision 1.1.1.1
1.1 misho 1: /*
2: * Copyright (c) 2013 Todd C. Miller <Todd.Miller@courtesan.com>
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 <config.h>
18:
19: #include <sys/param.h> /* for howmany() on Linux */
20: #include <sys/time.h>
21: #ifdef HAVE_SYS_SYSMACROS_H
22: # include <sys/sysmacros.h> /* for howmany() on Solaris */
23: #endif
24: #ifdef HAVE_SYS_SELECT_H
25: # include <sys/select.h>
26: #endif /* HAVE_SYS_SELECT_H */
27: #include <stdio.h>
28: #ifdef STDC_HEADERS
29: # include <stdlib.h>
30: # include <stddef.h>
31: #else
32: # ifdef HAVE_STDLIB_H
33: # include <stdlib.h>
34: # endif
35: #endif /* STDC_HEADERS */
36: #ifdef HAVE_STDBOOL_H
37: # include <stdbool.h>
38: #else
39: # include "compat/stdbool.h"
40: #endif /* HAVE_STDBOOL_H */
41: #ifdef HAVE_STRING_H
42: # include <string.h>
43: #endif /* HAVE_STRING_H */
44: #ifdef HAVE_STRINGS_H
45: # include <strings.h>
46: #endif /* HAVE_STRINGS_H */
47: #ifdef HAVE_UNISTD_H
48: # include <unistd.h>
49: #endif /* HAVE_UNISTD_H */
50: #include <errno.h>
51:
52: #include "missing.h"
53: #include "alloc.h"
54: #include "fatal.h"
55: #include "sudo_debug.h"
56: #include "sudo_event.h"
57: #include "sudo_util.h"
58:
59: /* XXX - use non-exiting allocators? */
60:
61: int
62: sudo_ev_base_alloc_impl(struct sudo_event_base *base)
63: {
64: debug_decl(sudo_ev_base_alloc_impl, SUDO_DEBUG_EVENT)
65:
66: base->maxfd = NFDBITS - 1;
67: base->readfds_in = ecalloc(1, sizeof(fd_mask));
68: base->writefds_in = ecalloc(1, sizeof(fd_mask));
69: base->readfds_out = ecalloc(1, sizeof(fd_mask));
70: base->writefds_out = ecalloc(1, sizeof(fd_mask));
71:
72: debug_return_int(0);
73: }
74:
75: void
76: sudo_ev_base_free_impl(struct sudo_event_base *base)
77: {
78: debug_decl(sudo_ev_base_free_impl, SUDO_DEBUG_EVENT)
79: efree(base->readfds_in);
80: efree(base->writefds_in);
81: efree(base->readfds_out);
82: efree(base->writefds_out);
83: debug_return;
84: }
85:
86: int
87: sudo_ev_add_impl(struct sudo_event_base *base, struct sudo_event *ev)
88: {
89: debug_decl(sudo_ev_add_impl, SUDO_DEBUG_EVENT)
90:
91: /* If out of space in fd sets, realloc. */
92: if (ev->fd > base->maxfd) {
93: const int o = (base->maxfd + 1) / NFDBITS;
94: const int n = howmany(ev->fd + 1, NFDBITS);
95: base->readfds_in = erecalloc(base->readfds_in, o, n, sizeof(fd_mask));
96: base->writefds_in = erecalloc(base->writefds_in, o, n, sizeof(fd_mask));
97: base->readfds_out = erecalloc(base->readfds_out, o, n, sizeof(fd_mask));
98: base->writefds_out = erecalloc(base->writefds_out, o, n, sizeof(fd_mask));
99: base->maxfd = (n * NFDBITS) - 1;
100: }
101:
102: /* Set events and adjust high fd as needed. */
103: if (ISSET(ev->events, SUDO_EV_READ)) {
104: sudo_debug_printf(SUDO_DEBUG_DEBUG, "%s: added fd %d to readfs",
105: __func__, ev->fd);
106: FD_SET(ev->fd, base->readfds_in);
107: }
108: if (ISSET(ev->events, SUDO_EV_WRITE)) {
109: sudo_debug_printf(SUDO_DEBUG_DEBUG, "%s: added fd %d to writefds",
110: __func__, ev->fd);
111: FD_SET(ev->fd, base->writefds_in);
112: }
113: if (ev->fd > base->highfd)
114: base->highfd = ev->fd;
115:
116: debug_return_int(0);
117: }
118:
119: int
120: sudo_ev_del_impl(struct sudo_event_base *base, struct sudo_event *ev)
121: {
122: debug_decl(sudo_ev_del_impl, SUDO_DEBUG_EVENT)
123:
124: /* Remove from readfds and writefds and adjust high fd. */
125: if (ISSET(ev->events, SUDO_EV_READ)) {
126: sudo_debug_printf(SUDO_DEBUG_DEBUG, "%s: removed fd %d from readfds",
127: __func__, ev->fd);
128: FD_CLR(ev->fd, base->readfds_in);
129: }
130: if (ISSET(ev->events, SUDO_EV_WRITE)) {
131: sudo_debug_printf(SUDO_DEBUG_DEBUG, "%s: removed fd %d from writefds",
132: __func__, ev->fd);
133: FD_CLR(ev->fd, base->writefds_in);
134: }
135: if (base->highfd == ev->fd) {
136: for (;;) {
137: if (FD_ISSET(base->highfd, base->readfds_in) ||
138: FD_ISSET(base->highfd, base->writefds_in))
139: break;
140: if (--base->highfd < 0)
141: break;
142: }
143: }
144:
145: debug_return_int(0);
146: }
147:
148: int
149: sudo_ev_scan_impl(struct sudo_event_base *base, int flags)
150: {
151: struct timeval now, tv, *timeout;
152: struct sudo_event *ev;
153: size_t setsize;
154: int nready;
155: debug_decl(sudo_ev_loop, SUDO_DEBUG_EVENT)
156:
157: if ((ev = TAILQ_FIRST(&base->timeouts)) != NULL) {
158: gettimeofday(&now, NULL);
159: sudo_timevalsub(&ev->timeout, &now, &tv);
160: if (tv.tv_sec < 0 || (tv.tv_sec == 0 && tv.tv_usec < 0))
161: sudo_timevalclear(&tv);
162: timeout = &tv;
163: } else {
164: if (ISSET(flags, SUDO_EVLOOP_NONBLOCK)) {
165: sudo_timevalclear(&tv);
166: timeout = &tv;
167: } else {
168: timeout = NULL;
169: }
170: }
171:
172: /* select() overwrites readfds/writefds so make a copy. */
173: setsize = howmany(base->highfd + 1, NFDBITS) * sizeof(fd_mask);
174: memcpy(base->readfds_out, base->readfds_in, setsize);
175: memcpy(base->writefds_out, base->writefds_in, setsize);
176:
177: sudo_debug_printf(SUDO_DEBUG_DEBUG, "%s: select high fd %d",
178: __func__, base->highfd);
179: nready = select(base->highfd + 1, base->readfds_out, base->writefds_out,
180: NULL, timeout);
181: sudo_debug_printf(SUDO_DEBUG_INFO, "%s: %d fds ready", __func__, nready);
182: switch (nready) {
183: case -1:
184: /* Error or interrupted by signal. */
185: debug_return_int(-1);
186: case 0:
187: /* Front end will activate timeout events. */
188: break;
189: default:
190: /* Activate each I/O event that fired. */
191: TAILQ_FOREACH(ev, &base->events, entries) {
192: if (ev->fd >= 0) {
193: int what = 0;
194: if (FD_ISSET(ev->fd, base->readfds_out))
195: what |= (ev->events & SUDO_EV_READ);
196: if (FD_ISSET(ev->fd, base->writefds_out))
197: what |= (ev->events & SUDO_EV_WRITE);
198: if (what != 0) {
199: /* Make event active. */
200: sudo_debug_printf(SUDO_DEBUG_DEBUG,
201: "%s: selected fd %d, events %d, activating %p",
202: __func__, ev->fd, what, ev);
203: ev->revents = what;
204: TAILQ_INSERT_TAIL(&base->active, ev, active_entries);
205: SET(ev->flags, SUDO_EVQ_ACTIVE);
206: }
207: }
208: }
209: break;
210: }
211: debug_return_int(nready);
212: }
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