diff options
| -rw-r--r-- | src/child.c | 405 | ||||
| -rw-r--r-- | src/child.h | 37 |
2 files changed, 442 insertions, 0 deletions
diff --git a/src/child.c b/src/child.c new file mode 100644 index 0000000..9ac74e4 --- /dev/null +++ b/src/child.c @@ -0,0 +1,405 @@ +/* $Id: child.c,v 1.1 2002-05-26 18:45:26 rjkaes Exp $ + * + * Handles the creation/destruction of the various children required for + * processing incoming connections. + * + * Copyright (C) 2000 Robert James Kaes (rjkaes@flarenet.com) + * + * 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 the + * Free Software Foundation; either version 2, or (at your option) any + * later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ + +#include "tinyproxy.h" + +#include "child.h" +#include "heap.h" +#include "log.h" +#include "reqs.h" +#include "sock.h" +#include "utils.h" + +static int listenfd; +static socklen_t addrlen; + +/* + * Stores the internal data needed for each child (connection) + */ +struct child_s { + pid_t tid; + unsigned int connects; + enum { T_EMPTY, T_WAITING, T_CONNECTED } status; +}; + +/* + * A pointer to an array of children. A certain number of children are + * created when the program is started. + */ +static struct child_s *child_ptr; + +static struct child_config_s { + unsigned int maxclients, maxrequestsperchild; + unsigned int maxspareservers, minspareservers, startservers; +} child_config; + +static int* servers_waiting; /* servers waiting for a connection */ + +/* + * Lock/Unlock the "servers_waiting" variable so that two children cannot + * modify it at the same time. + */ +#define SERVER_COUNT_LOCK() _child_lock_wait() +#define SERVER_COUNT_UNLOCK() _child_lock_release() + +/* START OF LOCKING SECTION */ + +/* + * These variables are required for the locking mechanism. Also included + * are the "private" functions for locking/unlocking. + */ +static struct flock lock_it, unlock_it; +static int lock_fd = -1; + +static void +_child_lock_init(void) +{ + char lock_file[] = "/tmp/tinyproxy.servers.lock.XXXXXX"; + + lock_fd = mkstemp(lock_file); + unlink(lock_file); + + lock_it.l_type = F_WRLCK; + lock_it.l_whence = SEEK_SET; + lock_it.l_start = 0; + lock_it.l_len = 0; + + unlock_it.l_type = F_UNLCK; + unlock_it.l_whence = SEEK_SET; + unlock_it.l_start = 0; + unlock_it.l_len = 0; +} + +static void +_child_lock_wait(void) +{ + int rc; + + while ((rc = fcntl(lock_fd, F_SETLKW, &lock_it)) < 0) { + if (errno == EINTR) + continue; + else + return; + } +} + +static void +_child_lock_release(void) +{ + if (fcntl(lock_fd, F_SETLKW, &unlock_it) < 0) + return; +} + +/* END OF LOCKING SECTION */ + +#define SERVER_INC() do { \ + SERVER_COUNT_LOCK(); \ + ++(*servers_waiting); \ + DEBUG2("INC: servers_waiting: %d", *servers_waiting); \ + SERVER_COUNT_UNLOCK(); \ +} while (0) + +#define SERVER_DEC() do { \ + SERVER_COUNT_LOCK(); \ + --(*servers_waiting); \ + DEBUG2("DEC: servers_waiting: %d", *servers_waiting); \ + SERVER_COUNT_UNLOCK(); \ +} while (0) + +/* + * Set the configuration values for the various child related settings. + */ +short int +child_configure(child_config_t type, unsigned int val) +{ + switch (type) { + case CHILD_MAXCLIENTS: + child_config.maxclients = val; + break; + case CHILD_MAXSPARESERVERS: + child_config.maxspareservers = val; + break; + case CHILD_MINSPARESERVERS: + child_config.minspareservers = val; + break; + case CHILD_STARTSERVERS: + child_config.startservers = val; + break; + case CHILD_MAXREQUESTSPERCHILD: + child_config.maxrequestsperchild = val; + break; + default: + DEBUG2("Invalid type (%d)", type); + return -1; + } + + return 0; +} + +/* + * This is the main (per child) loop. + */ +static void +child_main(struct child_s* ptr) +{ + int connfd; + struct sockaddr *cliaddr; + socklen_t clilen; + + cliaddr = safemalloc(addrlen); + if (!cliaddr) + exit(0); + + ptr->connects = 0; + + while (!config.quit) { + ptr->status = T_WAITING; + + clilen = addrlen; + + connfd = accept(listenfd, cliaddr, &clilen); + + /* + * Make sure no error occurred... + */ + if (connfd < 0) { + log_message(LOG_ERR, "Accept returned an error (%s) ... retrying.", strerror(errno)); + continue; + } + + ptr->status = T_CONNECTED; + + SERVER_DEC(); + + handle_connection(connfd); + + if (child_config.maxrequestsperchild != 0) { + ptr->connects++; + + DEBUG2("%u connections so far...", ptr->connects); + + if (ptr->connects >= child_config.maxrequestsperchild) { + log_message(LOG_NOTICE, + "Child has reached MaxRequestsPerChild (%u > %u). Killing child.", + ptr->connects, + child_config.maxrequestsperchild); + + break; + } + } + + SERVER_COUNT_LOCK(); + if (*servers_waiting > child_config.maxspareservers) { + /* + * There are too many spare children, kill ourself + * off. + */ + log_message(LOG_NOTICE, + "Waiting servers (%d) exceeds MaxSpareServers (%d). Killing child.", + *servers_waiting, child_config.maxspareservers); + SERVER_COUNT_UNLOCK(); + + break; + } else { + SERVER_COUNT_UNLOCK(); + } + + SERVER_INC(); + } + + ptr->status = T_EMPTY; + + safefree(cliaddr); + exit(0); +} + +/* + * Fork a child "child" (or in our case a process) and then start up the + * child_main() function. + */ +static int +child_make(struct child_s* ptr) +{ + pid_t pid; + + if ((pid = fork()) > 0) + return pid; /* parent */ + + child_main(ptr); /* never returns */ + return -1; +} + +/* + * Create a pool of children to handle incoming connections + */ +short int +child_pool_create(void) +{ + unsigned int i; + + /* + * Make sure the number of MaxClients is not zero, since this + * variable determines the size of the array created for children + * later on. + */ + if (child_config.maxclients == 0) { + log_message(LOG_ERR, + "child_pool_create: \"MaxClients\" must be greater than zero."); + return -1; + } + if (child_config.startservers == 0) { + log_message(LOG_ERR, + "child_pool_create: \"StartServers\" must be greater than zero."); + return -1; + } + + child_ptr = calloc_shared_memory(child_config.maxclients, + sizeof(struct child_s)); + if (!child_ptr) { + log_message(LOG_ERR, "Could not allocate memory for children."); + return -1; + } + + servers_waiting = malloc_shared_memory(sizeof(int)); + if (!servers_waiting) { + log_message(LOG_ERR, "Could not allocate memory for child counting."); + return -1; + } + *servers_waiting = 0; + + /* + * Create a "locking" file for use around the servers_waiting + * variable. + */ + _child_lock_init(); + + if (child_config.startservers > child_config.maxclients) { + log_message(LOG_WARNING, + "Can not start more than \"MaxClients\" servers. Starting %u servers instead.", + child_config.maxclients); + child_config.startservers = child_config.maxclients; + } + + for (i = 0; i < child_config.maxclients; i++) { + child_ptr[i].status = T_EMPTY; + child_ptr[i].connects = 0; + } + + for (i = 0; i < child_config.startservers; i++) { + DEBUG2("Trying to create child %d of %d", i + 1, child_config.startservers); + child_ptr[i].status = T_WAITING; + child_ptr[i].tid = child_make(&child_ptr[i]); + + if (child_ptr[i].tid < 0) { + log_message(LOG_WARNING, + "Could not create child number %d of %d", + i, child_config.startservers); + return -1; + } else { + log_message(LOG_INFO, + "Creating child number %d of %d ...", + i + 1, child_config.startservers); + + SERVER_INC(); + } + } + + log_message(LOG_INFO, "Finished creating all children."); + + return 0; +} + +/* + * Keep the proper number of servers running. This is the birth of the + * servers. It monitors this at least once a second. + */ +void +child_main_loop(void) +{ + int i; + + while (1) { + if (config.quit) + return; + + /* If there are not enough spare servers, create more */ + SERVER_COUNT_LOCK(); + if (*servers_waiting < child_config.minspareservers) { + log_message(LOG_NOTICE, + "Waiting servers (%d) is less than MinSpareServers (%d). Creating new child.", + *servers_waiting, child_config.minspareservers); + + SERVER_COUNT_UNLOCK(); + + for (i = 0; i < child_config.maxclients; i++) { + if (child_ptr[i].status == T_EMPTY) { + child_ptr[i].status = T_WAITING; + child_ptr[i].tid = child_make(&child_ptr[i]); + if (child_ptr[i].tid < 0) { + log_message(LOG_NOTICE, + "Could not create child"); + + child_ptr[i].status = T_EMPTY; + break; + } + + SERVER_INC(); + + break; + } + } + } else { + SERVER_COUNT_UNLOCK(); + } + + sleep(5); + + /* Handle log rotation if it was requested */ + if (log_rotation_request) { + rotate_log_files(); + log_rotation_request = FALSE; + } + } +} + +/* + * Go through all the non-empty children and cancel them. + */ +void +child_kill_children(void) +{ + int i; + + for (i = 0; i < child_config.maxclients; i++) { + if (child_ptr[i].status != T_EMPTY) + kill(child_ptr[i].tid, SIGTERM); + } +} + +int +child_listening_sock(uint16_t port) +{ + listenfd = listen_sock(port, &addrlen); + return listenfd; +} + +void +child_close_sock(void) +{ + close(listenfd); +} diff --git a/src/child.h b/src/child.h new file mode 100644 index 0000000..2ae5b3d --- /dev/null +++ b/src/child.h @@ -0,0 +1,37 @@ +/* $Id: child.h,v 1.1 2002-05-26 18:45:26 rjkaes Exp $ + * + * See 'child.c' for more information. + * + * Copyright (C) 2002 Robert James Kaes (rjkaes@flarenet.com) + * + * 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 the + * Free Software Foundation; either version 2, or (at your option) any + * later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ + +#ifndef TINYPROXY_CHILD_H +#define TINYPROXY_CHILD_H + +typedef enum { + CHILD_MAXCLIENTS, + CHILD_MAXSPARESERVERS, + CHILD_MINSPARESERVERS, + CHILD_STARTSERVERS, + CHILD_MAXREQUESTSPERCHILD +} child_config_t; + +extern short int child_pool_create(void); +extern int child_listening_sock(uint16_t port); +extern void child_close_sock(void); +extern void child_main_loop(void); +extern void child_kill_children(void); + +extern short int child_configure(child_config_t type, unsigned int val); + +#endif |