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/* |
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* ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd) |
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* |
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* Copyright (c) 1997-2020 ircd-hybrid development team |
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* |
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* This program is free software; you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License as published by |
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* the Free Software Foundation; either version 2 of the License, or |
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* (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 |
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* USA |
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*/ |
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|
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/*! \file fdlist.c |
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* \brief Maintains a list of file descriptors. |
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* \version $Id$ |
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*/ |
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|
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#include "stdinc.h" |
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#include "fdlist.h" |
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#include "irc_string.h" |
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#include "s_bsd.h" /* comm_setselect */ |
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#include "memory.h" |
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#include "misc.h" |
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|
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|
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fde_t *fd_table; |
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int number_fd = LEAKED_FDS; |
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int hard_fdlimit = 0; |
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int highest_fd = -1; |
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|
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|
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void |
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fdlist_init(void) |
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{ |
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/* |
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* Allow MAXCLIENTS_MIN clients even at the cost of MAX_BUFFER and |
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* some not really LEAKED_FDS |
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*/ |
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hard_fdlimit = IRCD_MAX(hard_fdlimit, LEAKED_FDS + MAX_BUFFER + MAXCLIENTS_MIN); |
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fd_table = xcalloc(sizeof(*fd_table) * hard_fdlimit); |
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} |
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|
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static void |
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fdlist_update_highest_fd(int fd, bool opening) |
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{ |
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if (fd < highest_fd) |
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return; |
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|
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assert(fd < hard_fdlimit); |
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|
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if (fd > highest_fd) |
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{ |
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/* |
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* assert() that we are not closing a FD bigger than our known highest FD. |
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*/ |
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assert(opening == true); |
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highest_fd = fd; |
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return; |
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} |
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|
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/* If we are here, then fd == highest_fd */ |
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/* |
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* assert() that we are closing the highest FD; we can't be re-opening it. |
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*/ |
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assert(opening == false); |
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|
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while (highest_fd >= 0 && fd_table[highest_fd].flags.open == false) |
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--highest_fd; |
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} |
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|
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/* Called to open a given filedescriptor */ |
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fde_t * |
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fd_open(int fd, bool is_socket, const char *desc) |
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{ |
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fde_t *F = &fd_table[fd]; |
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|
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assert(fd >= 0); |
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assert(F->fd == 0); |
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assert(F->flags.open == false); |
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|
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/* |
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* Note: normally we'd have to clear the other flags, but currently F |
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* is always cleared before calling us. |
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*/ |
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F->fd = fd; |
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F->comm_index = -1; |
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F->flags.open = true; |
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F->flags.is_socket = is_socket; |
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|
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if (desc) |
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F->desc = xstrndup(desc, FD_DESC_SIZE); |
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|
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fdlist_update_highest_fd(F->fd, true); |
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++number_fd; |
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|
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return F; |
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} |
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|
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/* Called to close a given filedescriptor */ |
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fde_t * |
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fd_close(fde_t *F) |
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{ |
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assert(F->fd >= 0); |
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assert(F->flags.open == true); |
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|
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if (F->flags.is_socket == true) |
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comm_setselect(F, COMM_SELECT_WRITE | COMM_SELECT_READ, NULL, NULL, 0); |
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|
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if (tls_isusing(&F->tls)) |
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tls_free(&F->tls); |
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|
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xfree(F->desc); |
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/* Unlike squid, we're actually closing the FD here! -- adrian */ |
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close(F->fd); |
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F->flags.open = false; /* Must set F->flags.open == false before fdlist_update_highest_fd() */ |
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|
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fdlist_update_highest_fd(F->fd, false); |
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--number_fd; |
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|
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memset(F, 0, sizeof(*F)); |
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|
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return F; |
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} |
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|
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/* |
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* fd_note() - set the fd note |
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* |
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* Note: must be careful not to overflow fd_table[fd].desc when |
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* calling. |
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*/ |
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void |
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fd_note(fde_t *F, const char *format, ...) |
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{ |
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if (format) |
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{ |
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char buf[FD_DESC_SIZE + 1]; |
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va_list args; |
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|
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va_start(args, format); |
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vsnprintf(buf, sizeof(buf), format, args); |
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va_end(args); |
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|
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xfree(F->desc); |
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F->desc = xstrdup(buf); |
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} |
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else |
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{ |
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xfree(F->desc); |
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F->desc = NULL; |
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} |
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} |
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|
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/* Make sure stdio descriptors (0-2) and profiler descriptor (3) |
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* always go somewhere harmless. Use -foreground for profiling |
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* or executing from gdb */ |
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void |
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close_standard_fds(void) |
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{ |
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for (int i = 0; i < LOWEST_SAFE_FD; ++i) |
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{ |
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close(i); |
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|
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if (open("/dev/null", O_RDWR) < 0) |
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exit(EXIT_FAILURE); /* we're hosed if we can't even open /dev/null */ |
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} |
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} |
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|
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void |
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close_fds(void) |
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{ |
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for (int fd = 0; fd <= highest_fd; ++fd) |
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close(fd); |
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} |
