File:  [ELWIX - Embedded LightWeight unIX -] / embedaddon / sudo / common / event_select.c
Revision 1.1.1.1 (vendor branch): download - view: text, annotated - select for diffs - revision graph
Sun Jun 15 16:12:54 2014 UTC (10 years, 2 months ago) by misho
Branches: sudo, MAIN
CVS tags: v1_8_10p3_0, v1_8_10p3, HEAD
sudo v 1.8.10p3

    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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