From c712ccebc993cad3f73000bbe9e4788ebeb95ca2 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 24 Apr 2012 10:55:33 +0200 Subject: conntrackd: generalize file descriptor infrastructure This patch generalizes the select-based file descriptor infrastructure by allowing you to register file descriptors and its callbacks. Instead of hardcoding the descriptors that needs to be checked. Now, struct fds_item contains a callback and pointer to data that is passed to it: struct fds_item { struct list_head head; int fd; + void (*cb)(void *data); + void *data; }; Then, we check which ones are active in the select_main_step() function: list_for_each_entry(cur, &STATE(fds)->list, head) { if (FD_ISSET(cur->fd, &readfds)) cur->cb(cur->data); } And it invoked the corresponding callback. I had to slightly modify the channel infrastructure to fit it into the changes. This modularity is required for the upcoming cthelper support. Signed-off-by: Pablo Neira Ayuso --- src/fds.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 58 insertions(+), 3 deletions(-) (limited to 'src/fds.c') diff --git a/src/fds.c b/src/fds.c index 347eee1..0b95437 100644 --- a/src/fds.c +++ b/src/fds.c @@ -1,5 +1,5 @@ /* - * (C) 2006-2008 by Pablo Neira Ayuso + * (C) 2006-2012 by Pablo Neira Ayuso * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -14,9 +14,16 @@ * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * Part of this code has been sponsored by Vyatta Inc. */ #include #include +#include +#include + +#include "conntrackd.h" +#include "date.h" #include "fds.h" struct fds *create_fds(void) @@ -44,7 +51,7 @@ void destroy_fds(struct fds *fds) free(fds); } -int register_fd(int fd, struct fds *fds) +int register_fd(int fd, void (*cb)(void *data), void *data, struct fds *fds) { struct fds_item *item; @@ -58,7 +65,10 @@ int register_fd(int fd, struct fds *fds) return -1; item->fd = fd; - list_add(&item->head, &fds->list); + item->cb = cb; + item->data = data; + /* Order matters: the descriptors are served in FIFO basis. */ + list_add_tail(&item->head, &fds->list); return 0; } @@ -92,3 +102,48 @@ int unregister_fd(int fd, struct fds *fds) return 0; } +static void select_main_step(struct timeval *next_alarm) +{ + int ret; + fd_set readfds = STATE(fds)->readfds; + struct fds_item *cur, *tmp; + + ret = select(STATE(fds)->maxfd + 1, &readfds, NULL, NULL, next_alarm); + if (ret == -1) { + /* interrupted syscall, retry */ + if (errno == EINTR) + return; + + STATE(stats).select_failed++; + return; + } + + /* signals are racy */ + sigprocmask(SIG_BLOCK, &STATE(block), NULL); + + list_for_each_entry_safe(cur, tmp, &STATE(fds)->list, head) { + if (FD_ISSET(cur->fd, &readfds)) + cur->cb(cur->data); + } + + sigprocmask(SIG_UNBLOCK, &STATE(block), NULL); +} + +void __attribute__((noreturn)) select_main_loop(void) +{ + struct timeval next_alarm; + struct timeval *next = NULL; + + while(1) { + do_gettimeofday(); + + sigprocmask(SIG_BLOCK, &STATE(block), NULL); + if (next != NULL && !timerisset(next)) + next = do_alarm_run(&next_alarm); + else + next = get_next_alarm_run(&next_alarm); + sigprocmask(SIG_UNBLOCK, &STATE(block), NULL); + + select_main_step(next); + } +} -- cgit v1.2.3