Annotation of embedaddon/sudo/common/event_poll.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/types.h>
                     20: #include <sys/time.h>
                     21: #include <stdio.h>
                     22: #ifdef STDC_HEADERS
                     23: # include <stdlib.h>
                     24: # include <stddef.h>
                     25: #else
                     26: # ifdef HAVE_STDLIB_H
                     27: #  include <stdlib.h>
                     28: # endif
                     29: #endif /* STDC_HEADERS */
                     30: #ifdef HAVE_STDBOOL_H
                     31: # include <stdbool.h>
                     32: #else
                     33: # include "compat/stdbool.h"
                     34: #endif /* HAVE_STDBOOL_H */
                     35: #ifdef HAVE_STRING_H
                     36: # include <string.h>
                     37: #endif /* HAVE_STRING_H */
                     38: #ifdef HAVE_STRINGS_H
                     39: # include <strings.h>
                     40: #endif /* HAVE_STRINGS_H */
                     41: #ifdef HAVE_UNISTD_H
                     42: # include <unistd.h>
                     43: #endif /* HAVE_UNISTD_H */
                     44: #include <errno.h>
                     45: #include <poll.h>
                     46: 
                     47: #include "missing.h"
                     48: #include "alloc.h"
                     49: #include "fatal.h"
                     50: #include "sudo_debug.h"
                     51: #include "sudo_event.h"
                     52: 
                     53: /* XXX - use non-exiting allocators? */
                     54: 
                     55: int
                     56: sudo_ev_base_alloc_impl(struct sudo_event_base *base)
                     57: {
                     58:     int i;
                     59:     debug_decl(sudo_ev_base_alloc_impl, SUDO_DEBUG_EVENT)
                     60: 
                     61:     base->pfd_high = -1;
                     62:     base->pfd_max = 32;
                     63:     base->pfds = erealloc3(NULL, base->pfd_max, sizeof(struct pollfd));
                     64:     for (i = 0; i < base->pfd_max; i++) {
                     65:        base->pfds[i].fd = -1;
                     66:     }
                     67: 
                     68:     debug_return_int(0);
                     69: }
                     70: 
                     71: void
                     72: sudo_ev_base_free_impl(struct sudo_event_base *base)
                     73: {
                     74:     debug_decl(sudo_ev_base_free_impl, SUDO_DEBUG_EVENT)
                     75:     efree(base->pfds);
                     76:     debug_return;
                     77: }
                     78: 
                     79: int
                     80: sudo_ev_add_impl(struct sudo_event_base *base, struct sudo_event *ev)
                     81: {
                     82:     struct pollfd *pfd;
                     83:     debug_decl(sudo_ev_add_impl, SUDO_DEBUG_EVENT)
                     84: 
                     85:     /* If out of space in pfds array, realloc. */
                     86:     if (base->pfd_free == base->pfd_max) {
                     87:        int i;
                     88:        base->pfd_max <<= 1;
                     89:        base->pfds =
                     90:            erealloc3(base->pfds, base->pfd_max, sizeof(struct pollfd));
                     91:        for (i = base->pfd_free; i < base->pfd_max; i++) {
                     92:            base->pfds[i].fd = -1;
                     93:        }
                     94:     }
                     95: 
                     96:     /* Fill in pfd entry. */
                     97:     ev->pfd_idx = base->pfd_free;
                     98:     pfd = &base->pfds[ev->pfd_idx];
                     99:     pfd->fd = ev->fd;
                    100:     pfd->events = 0;
                    101:     if (ISSET(ev->events, SUDO_EV_READ))
                    102:        pfd->events |= POLLIN;
                    103:     if (ISSET(ev->events, SUDO_EV_WRITE))
                    104:        pfd->events |= POLLOUT;
                    105: 
                    106:     /* Update pfd_high and pfd_free. */
                    107:     if (ev->pfd_idx > base->pfd_high)
                    108:        base->pfd_high = ev->pfd_idx;
                    109:     for (;;) {
                    110:        if (++base->pfd_free == base->pfd_max)
                    111:            break;
                    112:        if (base->pfds[base->pfd_free].fd == -1)
                    113:            break;
                    114:     }
                    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:     /* Mark pfd entry unused, add to free list and adjust high slot. */
                    125:     base->pfds[ev->pfd_idx].fd = -1;
                    126:     if (ev->pfd_idx < base->pfd_free)
                    127:        base->pfd_free = ev->pfd_idx;
                    128:     while (base->pfd_high >= 0 && base->pfds[base->pfd_high].fd == -1)
                    129:        base->pfd_high--;
                    130: 
                    131:     debug_return_int(0);
                    132: }
                    133: 
                    134: int
                    135: sudo_ev_scan_impl(struct sudo_event_base *base, int flags)
                    136: {
                    137:     struct sudo_event *ev;
                    138:     int nready, timeout;
                    139:     struct timeval now;
                    140:     debug_decl(sudo_ev_scan_impl, SUDO_DEBUG_EVENT)
                    141: 
                    142:     if ((ev = TAILQ_FIRST(&base->timeouts)) != NULL) {
                    143:        struct timeval *timo = &ev->timeout;
                    144:        gettimeofday(&now, NULL);
                    145:        timeout = ((timo->tv_sec - now.tv_sec) * 1000) +
                    146:            ((timo->tv_usec - now.tv_usec) / 1000);
                    147:        if (timeout <= 0)
                    148:            timeout = 0;
                    149:     } else {
                    150:        timeout = (flags & SUDO_EVLOOP_NONBLOCK) ? 0 : -1;
                    151:     }
                    152: 
                    153:     nready = poll(base->pfds, base->pfd_high + 1, timeout);
                    154:     sudo_debug_printf(SUDO_DEBUG_INFO, "%s: %d fds ready", __func__, nready);
                    155:     switch (nready) {
                    156:     case -1:
                    157:        /* Error or interrupted by signal. */
                    158:        debug_return_int(-1);
                    159:     case 0:
                    160:        /* Front end will activate timeout events. */
                    161:        break;
                    162:     default:
                    163:        /* Activate each I/O event that fired. */
                    164:        TAILQ_FOREACH(ev, &base->events, entries) {
                    165:            if (ev->pfd_idx != -1 && base->pfds[ev->pfd_idx].revents) {
                    166:                int what = 0;
                    167:                if (base->pfds[ev->pfd_idx].revents & (POLLIN|POLLHUP|POLLNVAL|POLLERR))
                    168:                    what |= (ev->events & SUDO_EV_READ);
                    169:                if (base->pfds[ev->pfd_idx].revents & (POLLOUT|POLLHUP|POLLNVAL|POLLERR))
                    170:                    what |= (ev->events & SUDO_EV_WRITE);
                    171:                /* Make event active. */
                    172:                sudo_debug_printf(SUDO_DEBUG_DEBUG,
                    173:                    "%s: polled fd %d, events %d, activating %p",
                    174:                    __func__, ev->fd, what, ev);
                    175:                ev->revents = what;
                    176:                TAILQ_INSERT_TAIL(&base->active, ev, active_entries);
                    177:                SET(ev->flags, SUDO_EVQ_ACTIVE);
                    178:            }
                    179:        }
                    180:        break;
                    181:     }
                    182:     debug_return_int(nready);
                    183: }

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