| 1 | /* |
| 2 | * poll.c |
| 3 | * - wrappers for poll(2) |
| 4 | */ |
| 5 | /* |
| 6 | * This file is part of adns, which is |
| 7 | * Copyright (C) 1997-2000,2003,2006,2014-2016 Ian Jackson |
| 8 | * Copyright (C) 2014 Mark Wooding |
| 9 | * Copyright (C) 1999-2000,2003,2006 Tony Finch |
| 10 | * Copyright (C) 1991 Massachusetts Institute of Technology |
| 11 | * (See the file INSTALL for full details.) |
| 12 | * |
| 13 | * This program is free software; you can redistribute it and/or modify |
| 14 | * it under the terms of the GNU General Public License as published by |
| 15 | * the Free Software Foundation; either version 3, or (at your option) |
| 16 | * any later version. |
| 17 | * |
| 18 | * This program is distributed in the hope that it will be useful, |
| 19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 21 | * GNU General Public License for more details. |
| 22 | * |
| 23 | * You should have received a copy of the GNU General Public License |
| 24 | * along with this program; if not, write to the Free Software Foundation. |
| 25 | */ |
| 26 | |
| 27 | #include <limits.h> |
| 28 | #include <string.h> |
| 29 | |
| 30 | #include "internal.h" |
| 31 | |
| 32 | #ifdef HAVE_POLL |
| 33 | |
| 34 | int adns_beforepoll(adns_state ads, struct pollfd *fds, int *nfds_io, |
| 35 | int *timeout_io, const struct timeval *now) { |
| 36 | struct timeval tv_nowbuf, tv_tobuf, *tv_to; |
| 37 | int space, found, timeout_ms, r; |
| 38 | struct pollfd fds_tmp[MAX_POLLFDS]; |
| 39 | |
| 40 | adns__consistency(ads,0,cc_entex); |
| 41 | |
| 42 | if (timeout_io) { |
| 43 | adns__must_gettimeofday(ads,&now,&tv_nowbuf); |
| 44 | if (!now) { *nfds_io= 0; r= 0; goto xit; } |
| 45 | |
| 46 | timeout_ms= *timeout_io; |
| 47 | if (timeout_ms == -1) { |
| 48 | tv_to= 0; |
| 49 | } else { |
| 50 | tv_tobuf.tv_sec= timeout_ms / 1000; |
| 51 | tv_tobuf.tv_usec= (timeout_ms % 1000)*1000; |
| 52 | tv_to= &tv_tobuf; |
| 53 | } |
| 54 | |
| 55 | adns__timeouts(ads, 0, &tv_to,&tv_tobuf, *now); |
| 56 | |
| 57 | if (tv_to) { |
| 58 | assert(tv_to == &tv_tobuf); |
| 59 | timeout_ms= (tv_tobuf.tv_usec+999)/1000; |
| 60 | assert(tv_tobuf.tv_sec < (INT_MAX-timeout_ms)/1000); |
| 61 | timeout_ms += tv_tobuf.tv_sec*1000; |
| 62 | } else { |
| 63 | timeout_ms= -1; |
| 64 | } |
| 65 | *timeout_io= timeout_ms; |
| 66 | } |
| 67 | |
| 68 | space= *nfds_io; |
| 69 | if (space >= MAX_POLLFDS) { |
| 70 | found= adns__pollfds(ads,fds); |
| 71 | *nfds_io= found; |
| 72 | } else { |
| 73 | found= adns__pollfds(ads,fds_tmp); |
| 74 | *nfds_io= found; |
| 75 | if (space < found) { r= ERANGE; goto xit; } |
| 76 | memcpy(fds,fds_tmp,sizeof(struct pollfd)*found); |
| 77 | } |
| 78 | r= 0; |
| 79 | xit: |
| 80 | adns__returning(ads,0); |
| 81 | return r; |
| 82 | } |
| 83 | |
| 84 | void adns_afterpoll(adns_state ads, const struct pollfd *fds, int nfds, |
| 85 | const struct timeval *now) { |
| 86 | struct timeval tv_buf; |
| 87 | |
| 88 | adns__consistency(ads,0,cc_entex); |
| 89 | adns__must_gettimeofday(ads,&now,&tv_buf); |
| 90 | if (now) { |
| 91 | adns__timeouts(ads, 1, 0,0, *now); |
| 92 | adns__fdevents(ads, fds,nfds, 0,0,0,0, *now,0); |
| 93 | } |
| 94 | adns__returning(ads,0); |
| 95 | } |
| 96 | |
| 97 | int adns_wait_poll(adns_state ads, |
| 98 | adns_query *query_io, |
| 99 | adns_answer **answer_r, |
| 100 | void **context_r) { |
| 101 | int r, nfds, to; |
| 102 | struct pollfd fds[MAX_POLLFDS]; |
| 103 | |
| 104 | adns__consistency(ads,0,cc_entex); |
| 105 | |
| 106 | for (;;) { |
| 107 | r= adns__internal_check(ads,query_io,answer_r,context_r); |
| 108 | if (r != EAGAIN) goto xit; |
| 109 | nfds= MAX_POLLFDS; to= -1; |
| 110 | adns_beforepoll(ads,fds,&nfds,&to,0); |
| 111 | r= poll(fds,nfds,to); |
| 112 | if (r == -1) { |
| 113 | if (errno == EINTR) { |
| 114 | if (ads->iflags & adns_if_eintr) { r= EINTR; goto xit; } |
| 115 | } else { |
| 116 | adns__diag(ads,-1,0,"poll failed in wait: %s",strerror(errno)); |
| 117 | adns_globalsystemfailure(ads); |
| 118 | } |
| 119 | } else { |
| 120 | assert(r >= 0); |
| 121 | adns_afterpoll(ads,fds,nfds,0); |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | xit: |
| 126 | adns__returning(ads,0); |
| 127 | return r; |
| 128 | } |
| 129 | |
| 130 | #endif |