commit 78ecedcc4e318aebb8d66a3d848f7cc5f3d00bc6 Author: Olaf Rempel Date: Sat Nov 25 14:31:52 2006 +0100 initial diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..3712a6f --- /dev/null +++ b/.gitignore @@ -0,0 +1,3 @@ +*.d +*.o +telnetproxy diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..e7c1c2b --- /dev/null +++ b/Makefile @@ -0,0 +1,22 @@ +VERSION := v0.01 + +CFLAGS := -O2 -pipe -Wall -DVERSION='"$(VERSION)"' + +OBJS := configfile.o connection.o event.o logging.o network.o telnetproxy.o + +all: telnetproxy + +telnetproxy: $(OBJS) + $(CC) $(CFLAGS) $^ -o $@ + +%.o: %.c + $(CC) $(CFLAGS) -c $< -o $@ + +%.d: %.c + $(CC) $(CFLAGS) -MM -c $< -o $@ + +clean: + rm -f telnetproxy *.d *.o *.log + +DEPS := $(wildcard *.c) +-include $(DEPS:.c=.d) diff --git a/configfile.c b/configfile.c new file mode 100644 index 0000000..73ff3ae --- /dev/null +++ b/configfile.c @@ -0,0 +1,200 @@ +/*************************************************************************** + * Copyright (C) 06/2006 by Olaf Rempel * + * razzor@kopf-tisch.de * + * * + * 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 of the License, 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. * + * * + * 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., * + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * + ***************************************************************************/ +#include +#include +#include +#include + +#include +#include +#include +#include + +#include "configfile.h" +#include "list.h" +#include "logging.h" + +#define BUFSIZE 1024 + +struct conf_section { + struct list_head list; + struct list_head tupel_list; + char *name; +}; + +struct conf_tupel { + struct list_head list; + char *option; + char *parameter; +}; + +static LIST_HEAD(config_list); + +static struct conf_section * config_add_section(const char *name) +{ + struct conf_section *section; + section = malloc(sizeof(struct conf_section) + strlen(name)); + if (section == NULL) + return NULL; + + INIT_LIST_HEAD(§ion->list); + INIT_LIST_HEAD(§ion->tupel_list); + + section->name = strdup(name); + if (section->name == NULL) { + free(section); + return NULL; + } + + list_add_tail(§ion->list, &config_list); + return section; +} + +static int config_add_tupel(struct conf_section *section, const char *option, const char *parameter) +{ + struct conf_tupel *tupel = malloc(sizeof(struct conf_tupel)); + if (tupel == NULL) + return -1; + + INIT_LIST_HEAD(&tupel->list); + tupel->option = strdup(option); + tupel->parameter = strdup(parameter); + + if (tupel->option == NULL || tupel->parameter == NULL) { + free(tupel); + return -1; + } + + list_add_tail(&tupel->list, §ion->tupel_list); + return 0; +} + +int config_parse(const char *config) +{ + FILE *fz = fopen(config, "r"); + if (fz == NULL) { + log_print(LOG_ERROR, "config_parse(): %s", config); + return -1; + } + + char *line = malloc(BUFSIZE); + if (line == NULL) { + log_print(LOG_ERROR, "config_parse(): out of memory"); + fclose(fz); + return -1; + } + + int linenum = 0; + struct conf_section *section = NULL; + while (fgets(line, BUFSIZE, fz) != NULL) { + linenum++; + + if (line[0] == '#' || line[0] <= ' ') { + continue; + + } else if (line[0] == '[') { + char *tok = strtok(line +1, " ]\n"); + + if (tok == NULL || (section = config_add_section(tok)) == NULL) { + log_print(LOG_WARN, "config_parse(): invalid section in row %d", linenum); + free(line); + fclose(fz); + return -1; + } + continue; + + } else if (section == NULL) { + log_print(LOG_WARN, "config_parse(): missing section in row %d", linenum); + free(line); + fclose(fz); + return -1; + } + + char *tok = strtok(line, " \n"); + if (tok != NULL) { + char *tok2; + while ((tok2 = strtok(NULL, " \n"))) { + if (config_add_tupel(section, tok, tok2) != 0) + log_print(LOG_WARN, "config_parse(): invalid row %d", linenum); + } + } + } + + fclose(fz); + free(line); + return 0; +} + +static struct conf_section * config_get_section(const char *name) +{ + struct conf_section *section; + + list_for_each_entry(section, &config_list, list) { + if (!strcmp(section->name, name)) + return section; + } + return NULL; +} + +char * config_get_string(const char *section_str, const char *option, char *def) +{ + struct conf_section *section = config_get_section(section_str); + if (section != NULL) { + struct conf_tupel *tupel; + list_for_each_entry(tupel, §ion->tupel_list, list) { + if (!strcmp(tupel->option, option)) + return tupel->parameter; + } + } + + if (def != NULL) + log_print(LOG_WARN, "config [%s:%s] not found, using default: '%s'", + section_str, option, def); + return def; +} + +int config_get_int(const char *section, const char *option, int def) +{ + char *ret = config_get_string(section, option, NULL); + if (ret == NULL) { + log_print(LOG_WARN, "config [%s:%s] not found, using default: '%d'", + section, option, def); + return def; + } + return atoi(ret); +} + +int config_get_strings(const char *section_str, const char *option, + int (*callback)(const char *value, void *privdata), + void *privdata) +{ + struct conf_section *section = config_get_section(section_str); + if (section == NULL) + return -1; + + int cnt = 0; + struct conf_tupel *tupel; + list_for_each_entry(tupel, §ion->tupel_list, list) { + if (!strcmp(tupel->option, option)) + if (callback(tupel->parameter, privdata) == 0) + cnt++; + } + return cnt; +} diff --git a/configfile.h b/configfile.h new file mode 100644 index 0000000..6528459 --- /dev/null +++ b/configfile.h @@ -0,0 +1,16 @@ +#ifndef _CONFIG_H_ +#define _CONFIG_H_ + +#include + +int config_parse(const char *config); + +char * config_get_string(const char *section_str, const char *option, char *def); + +int config_get_int(const char *section, const char *option, int def); + +int config_get_strings(const char *section_str, const char *option, + int (*callback)(const char *value, void *privdata), + void *privdata); + +#endif /* _CONFIG_H_ */ diff --git a/connection.c b/connection.c new file mode 100644 index 0000000..eb88ca4 --- /dev/null +++ b/connection.c @@ -0,0 +1,5 @@ +#include +#include +#include + +#include "connection.h" diff --git a/connection.h b/connection.h new file mode 100644 index 0000000..724bce9 --- /dev/null +++ b/connection.h @@ -0,0 +1,23 @@ +#ifndef _CONNECTION_H_ +#define _CONNECTION_H_ + +#include + +#include "list.h" + +struct connection { + struct list_head list; + + struct sockaddr_in src_addr; + struct sockaddr_in dst_addr; + + int src_fd; + int dst_fd; + + unsigned long login_time; + unsigned long idle_time; + + char user[32]; +}; + +#endif // _CONNECTION_H_ diff --git a/event.c b/event.c new file mode 100644 index 0000000..2d34826 --- /dev/null +++ b/event.c @@ -0,0 +1,310 @@ +/*************************************************************************** + * Copyright (C) 10/2006 by Olaf Rempel * + * razzor@kopf-tisch.de * + * * + * 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 of the License, 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. * + * * + * 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., * + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * + ***************************************************************************/ +#include +#include +#include + +#include +#include + +#include "list.h" +#include "logging.h" + +#include "event.h" + +static LIST_HEAD(readfd_list); +static LIST_HEAD(writefd_list); +static LIST_HEAD(exceptfd_list); +static LIST_HEAD(timeout_list); + +struct fd_entry { + struct list_head list; + int fd; + int type; + int (*callback)(int fd, void *privdata); + void *privdata; +}; + +struct timeout_entry { + struct list_head list; + struct timeval timeout; + struct timeval nextrun; + int (*callback)(void *privdata); + void *privdata; +}; + +int event_add_fd(int fd, int type, int (*callback)(int fd, void *privdata), void *privdata) +{ + if (fd < 0 || fd > FD_SETSIZE) + return -1; + + struct fd_entry *entry; + entry = malloc(sizeof(struct fd_entry)); + if (entry == NULL) { + log_print(LOG_ERROR, "event_add_fd(): out of memory"); + return -1; + } + + entry->fd = fd; + entry->type = type; + entry->callback = callback; + entry->privdata = privdata; + + switch (type) { + case FD_READ: + list_add_tail(&entry->list, &readfd_list); + break; + + case FD_WRITE: + list_add_tail(&entry->list, &writefd_list); + break; + + case FD_EXCEPT: + list_add_tail(&entry->list, &exceptfd_list); + break; + + default: + log_print(LOG_ERROR, "add_fd(): unknown type"); + free(entry); + return -1; + } + + return 0; +} + +int event_remove_fd(int fd) +{ + struct fd_entry *entry, *tmp; + list_for_each_entry_safe(entry, tmp, &readfd_list, list) { + if (entry->fd == fd) { + list_del(&entry->list); + free(entry); + return 0; + } + } + + list_for_each_entry_safe(entry, tmp, &writefd_list, list) { + if (entry->fd == fd) { + list_del(&entry->list); + free(entry); + return 0; + } + } + + list_for_each_entry_safe(entry, tmp, &exceptfd_list, list) { + if (entry->fd == fd) { + list_del(&entry->list); + free(entry); + return 0; + } + } + + return -1; +} + +static void calc_nextrun(struct timeval *timeout, struct timeval *nextrun) +{ + struct timeval now; + gettimeofday(&now, NULL); + + nextrun->tv_usec = now.tv_usec + timeout->tv_usec; + nextrun->tv_sec = now.tv_sec + timeout->tv_sec; + + if (nextrun->tv_usec >= 1000000) { + nextrun->tv_usec -= 1000000; + nextrun->tv_sec++; + } +} + +static void calc_timeout(struct timeval *timeout, struct timeval *nextrun) +{ + struct timeval now; + gettimeofday(&now, NULL); + + timeout->tv_usec = nextrun->tv_usec - now.tv_usec; + timeout->tv_sec = nextrun->tv_sec - now.tv_sec; + + if (timeout->tv_usec < 0) { + timeout->tv_usec += 1000000; + timeout->tv_sec--; + } +} + +static void schedule_nextrun(struct timeout_entry *entry) +{ + struct timeout_entry *search; + + list_for_each_entry(search, &timeout_list, list) { + if (search->nextrun.tv_sec > entry->nextrun.tv_sec) { + list_add_tail(&entry->list, &search->list); + return; + + } else if (search->nextrun.tv_sec == entry->nextrun.tv_sec && + search->nextrun.tv_usec > entry->nextrun.tv_usec) { + list_add_tail(&entry->list, &search->list); + return; + } + } + list_add_tail(&entry->list, &timeout_list); +} + +int event_add_timeout(struct timeval *timeout, int (*callback)(void *privdata), void *privdata) +{ + struct timeout_entry *entry; + entry = malloc(sizeof(struct timeout_entry)); + if (entry == NULL) { + log_print(LOG_ERROR, "event_add_timeout(): out of memory"); + return -1; + } + + memcpy(&entry->timeout, timeout, sizeof(entry->timeout)); + entry->callback = callback; + entry->privdata = privdata; + + calc_nextrun(&entry->timeout, &entry->nextrun); + schedule_nextrun(entry); + return 0; +} + +void event_loop(void) +{ + while (1) { + fd_set readfds, *readfds_p = NULL; + fd_set writefds, *writefds_p = NULL; + fd_set exceptfds, *exceptfds_p =NULL; + struct timeval timeout, *timeout_p = NULL; + + if (!list_empty(&readfd_list)) { + struct fd_entry *entry; + + FD_ZERO(&readfds); + list_for_each_entry(entry, &readfd_list, list) + FD_SET(entry->fd, &readfds); + + readfds_p = &readfds; + } + + if (!list_empty(&writefd_list)) { + struct fd_entry *entry; + + FD_ZERO(&writefds); + list_for_each_entry(entry, &writefd_list, list) + FD_SET(entry->fd, &writefds); + + writefds_p = &writefds; + } + + if (!list_empty(&exceptfd_list)) { + struct fd_entry *entry; + + FD_ZERO(&exceptfds); + list_for_each_entry(entry, &exceptfd_list, list) + FD_SET(entry->fd, &exceptfds); + + exceptfds_p = &exceptfds; + } + + if (!list_empty(&timeout_list)) { + struct timeout_entry *entry, *tmp; + list_for_each_entry_safe(entry, tmp, &timeout_list, list) { + + calc_timeout(&timeout, &entry->nextrun); + if (timeout.tv_sec >= 0 && timeout.tv_usec > 0) { + timeout_p = &timeout; + break; + } + + // delayed timeout, exec NOW! + list_del(&entry->list); + int ret = entry->callback(entry->privdata); + if (ret == 0) { + calc_nextrun(&entry->timeout, &entry->nextrun); + schedule_nextrun(entry); + + } else { + free(entry); + } + } + } + + int i = select(FD_SETSIZE, readfds_p, writefds_p, exceptfds_p, timeout_p); + if (i < 0) { + /* On error, -1 is returned, and errno is set + * appropriately; the sets and timeout become + * undefined, so do not rely on their contents + * after an error. + */ + continue; + + } else if (i == 0 && !list_empty(&timeout_list)) { + struct timeout_entry *entry; + entry = list_entry(timeout_list.next, typeof(*entry), list); + list_del(&entry->list); + + int ret = entry->callback(entry->privdata); + if (ret == 0) { + calc_nextrun(&entry->timeout, &entry->nextrun); + schedule_nextrun(entry); + + } else { + free(entry); + } + } + + if (readfds_p) { + struct fd_entry *entry, *tmp; + list_for_each_entry_safe(entry, tmp, &readfd_list, list) { + if (!FD_ISSET(entry->fd, &readfds)) + continue; + + if (entry->callback(entry->fd, entry->privdata) != 0) { + list_del(&entry->list); + free(entry); + } + } + } + + if (writefds_p) { + struct fd_entry *entry, *tmp; + list_for_each_entry_safe(entry, tmp, &writefd_list, list) { + if (FD_ISSET(entry->fd, &writefds)) + continue; + + if (entry->callback(entry->fd, entry->privdata) != 0) { + list_del(&entry->list); + free(entry); + } + } + } + + if (exceptfds_p) { + struct fd_entry *entry, *tmp; + list_for_each_entry_safe(entry, tmp, &exceptfd_list, list) { + if (FD_ISSET(entry->fd, &exceptfds)) + continue; + + if (entry->callback(entry->fd, entry->privdata) != 0) { + list_del(&entry->list); + free(entry); + } + } + } + } +} diff --git a/event.h b/event.h new file mode 100644 index 0000000..df7a396 --- /dev/null +++ b/event.h @@ -0,0 +1,26 @@ +#ifndef _EVENT_H_ +#define _EVENT_H_ + +#include + +#define FD_READ 0x01 +#define FD_WRITE 0x02 +#define FD_EXCEPT 0x04 + +#define event_add_readfd(fd, callback, privdata) \ + event_add_fd(fd, FD_READ, callback, privdata) + +#define event_add_writefd(fd, callback, privdata) \ + event_add_fd(fd, FD_WRITE, callback, privdata) + +#define event_add_exceptfd(fd, callback, privdata) \ + event_add_fd(fd, FD_EXCEPT, callback, privdata) + +int event_add_fd(int fd, int type, int (*callback)(int fd, void *privdata), void *privdata); +int event_add_timeout(struct timeval *timeout, int (*callback)(void *privdata), void *privdata); + +int event_remove_fd(int fd); + +void event_loop(void); + +#endif /* _EVENT_H_ */ diff --git a/list.h b/list.h new file mode 100644 index 0000000..61f8d93 --- /dev/null +++ b/list.h @@ -0,0 +1,268 @@ +#ifndef _LIST_H_ +#define _LIST_H_ + +/* + * stolen from linux kernel 2.6.11 (http://kernel.org/) + * linux/include/linux/stddef.h (offsetoff) + * linux/include/linux/kernel.h (container_of) + * linux/include/linux/list.h (*list*) + * linux/include/linux/netfilter_ipv4/listhelp.h (LIST_FIND) + * + * modified by Olaf Rempel + */ +#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER) + +#define container_of(ptr, type, member) ({ \ + const typeof( ((type *)0)->member ) *__mptr = (ptr); \ + (type *)( (char *)__mptr - offsetof(type,member) );}) + +struct list_head { + struct list_head *next, *prev; +}; + +#define LIST_HEAD_INIT(name) { &(name), &(name) } + +#define LIST_HEAD(name) \ + struct list_head name = LIST_HEAD_INIT(name) + +#define INIT_LIST_HEAD(ptr) do { \ + (ptr)->next = (ptr); (ptr)->prev = (ptr); \ +} while (0) + +/* + * Insert a new entry between two known consecutive entries. + * + * This is only for internal list manipulation where we know + * the prev/next entries already! + */ +static inline void __list_add(struct list_head *new, + struct list_head *prev, + struct list_head *next) +{ + next->prev = new; + new->next = next; + new->prev = prev; + prev->next = new; +} + +/* + * list_add - add a new entry + * @new: new entry to be added + * @head: list head to add it after + * + * Insert a new entry after the specified head. + * This is good for implementing stacks. + */ +static inline void list_add(struct list_head *new, struct list_head *head) +{ + __list_add(new, head, head->next); +} + +/* + * list_add_tail - add a new entry + * @new: new entry to be added + * @head: list head to add it before + * + * Insert a new entry before the specified head. + * This is useful for implementing queues. + */ +static inline void list_add_tail(struct list_head *new, struct list_head *head) +{ + __list_add(new, head->prev, head); +} + +/* + * Delete a list entry by making the prev/next entries + * point to each other. + * + * This is only for internal list manipulation where we know + * the prev/next entries already! + */ +static inline void __list_del(struct list_head * prev, struct list_head * next) +{ + next->prev = prev; + prev->next = next; +} + +/* + * list_del - deletes entry from list. + * @entry: the element to delete from the list. + * Note: list_empty on entry does not return true after this, the entry is + * in an undefined state. + */ +static inline void list_del(struct list_head *entry) +{ + __list_del(entry->prev, entry->next); + entry->next = NULL; + entry->prev = NULL; +} + +/* + * list_del_init - deletes entry from list and reinitialize it. + * entry: the element to delete from the list. + */ +static inline void list_del_init(struct list_head *entry) +{ + __list_del(entry->prev, entry->next); + INIT_LIST_HEAD(entry); +} + +/* + * list_move - delete from one list and add as another's head + * @list: the entry to move + * @head: the head that will precede our entry + */ +static inline void list_move(struct list_head *list, struct list_head *head) +{ + __list_del(list->prev, list->next); + list_add(list, head); +} + +/* + * list_move_tail - delete from one list and add as another's tail + * @list: the entry to move + * @head: the head that will follow our entry + */ +static inline void list_move_tail(struct list_head *list, + struct list_head *head) +{ + __list_del(list->prev, list->next); + list_add_tail(list, head); +} + +/* + * list_empty - tests whether a list is empty + * @head: the list to test. + */ +static inline int list_empty(const struct list_head *head) +{ + return head->next == head; +} + +static inline void __list_splice(struct list_head *list, + struct list_head *head) +{ + struct list_head *first = list->next; + struct list_head *last = list->prev; + struct list_head *at = head->next; + + first->prev = head; + head->next = first; + + last->next = at; + at->prev = last; +} + +/* + * list_splice - join two lists + * @list: the new list to add. + * @head: the place to add it in the first list. + */ +static inline void list_splice(struct list_head *list, struct list_head *head) +{ + if (!list_empty(list)) + __list_splice(list, head); +} + +/* + * list_splice_init - join two lists and reinitialise the emptied list. + * @list: the new list to add. + * @head: the place to add it in the first list. + * + * The list at @list is reinitialised + */ +static inline void list_splice_init(struct list_head *list, + struct list_head *head) +{ + if (!list_empty(list)) { + __list_splice(list, head); + INIT_LIST_HEAD(list); + } +} + +/* + * list_entry - get the struct for this entry + * @ptr: the &struct list_head pointer. + * @type: the type of the struct this is embedded in. + * @member: the name of the list_struct within the struct. + */ +#define list_entry(ptr, type, member) \ + container_of(ptr, type, member) + +/* + * list_for_each - iterate over a list + * @pos: the &struct list_head to use as a loop counter. + * @head: the head for your list. + */ +#define list_for_each(pos, head) \ + for (pos = (head)->next; pos != (head); pos = pos->next) + +/* + * list_for_each_prev - iterate over a list backwards + * @pos: the &struct list_head to use as a loop counter. + * @head: the head for your list. + */ +#define list_for_each_prev(pos, head) \ + for (pos = (head)->prev; pos != (head); pos = pos->prev) + +/* + * list_for_each_safe - iterate over a list safe against removal of list entry + * @pos: the &struct list_head to use as a loop counter. + * @n: another &struct list_head to use as temporary storage + * @head: the head for your list. + */ +#define list_for_each_safe(pos, n, head) \ + for (pos = (head)->next, n = pos->next; pos != (head); \ + pos = n, n = pos->next) + +/* + * list_for_each_entry - iterate over list of given type + * @pos: the type * to use as a loop counter. + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + */ +#define list_for_each_entry(pos, head, member) \ + for (pos = list_entry((head)->next, typeof(*pos), member); \ + &pos->member != (head); \ + pos = list_entry(pos->member.next, typeof(*pos), member)) + +/* + * list_for_each_entry_reverse - iterate backwards over list of given type. + * @pos: the type * to use as a loop counter. + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + */ +#define list_for_each_entry_reverse(pos, head, member) \ + for (pos = list_entry((head)->prev, typeof(*pos), member); \ + &pos->member != (head); \ + pos = list_entry(pos->member.prev, typeof(*pos), member)) + +/* + * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry + * @pos: the type * to use as a loop counter. + * @n: another type * to use as temporary storage + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + */ +#define list_for_each_entry_safe(pos, n, head, member) \ + for (pos = list_entry((head)->next, typeof(*pos), member), \ + n = list_entry(pos->member.next, typeof(*pos), member); \ + &pos->member != (head); \ + pos = n, n = list_entry(n->member.next, typeof(*n), member)) + + +/* Return pointer to first true entry, if any, or NULL. A macro + required to allow inlining of cmpfn. */ +#define LIST_FIND(head, cmpfn, type, args...) \ +({ \ + const struct list_head *__i, *__j = NULL; \ + \ + list_for_each(__i, (head)) \ + if (cmpfn((const type)__i , ## args)) { \ + __j = __i; \ + break; \ + } \ + (type)__j; \ +}) + +#endif /* _LIST_H_ */ diff --git a/logging.c b/logging.c new file mode 100644 index 0000000..d4fd706 --- /dev/null +++ b/logging.c @@ -0,0 +1,103 @@ +/*************************************************************************** + * Copyright (C) 06/2006 by Olaf Rempel * + * razzor@kopf-tisch.de * + * * + * 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 of the License, 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. * + * * + * 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., * + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * + ***************************************************************************/ +#include +#include +#include +#include +#include +#include + +#include "logging.h" + +#define BUFSIZE 8192 + +static FILE *log_fd = NULL; +static char *buffer = NULL; + +void log_print(int prio, const char *fmt, ...) +{ + va_list az; + int len; + + if (buffer == NULL) { + buffer = malloc(BUFSIZE); + if (buffer == NULL) { + fprintf(stderr, "log_print: out of memory\nBailing out!\n"); + exit(-1); + } + } + + va_start(az, fmt); + len = vsnprintf(buffer, BUFSIZE, fmt, az); + va_end(az); + + if (len < 0 || len >= BUFSIZE) { + log_print(LOG_ERROR, "log_print: arguments too long"); + errno = 0; + return; + } + + if (errno) { + strncpy(buffer + len, ": ", BUFSIZE - len); + len += 2; + strncpy(buffer + len, strerror(errno), BUFSIZE - len); + } + + if (log_fd) { + char tbuf[64]; + time_t tzgr; + + time(&tzgr); + strftime(tbuf, sizeof(tbuf), "%b %d %H:%M:%S :", localtime(&tzgr)); + + fprintf(log_fd, "%s %s\n", tbuf, buffer); + fflush(log_fd); + + } else { + fprintf(stderr, "%s\n", buffer); + } + + errno = 0; +} + +static void log_close(void) +{ + if (buffer) + free(buffer); + + fclose(log_fd); +} + +int log_init(char *logfile) +{ + log_fd = fopen(logfile, "a"); + if (log_fd == NULL) { + log_print(LOG_ERROR, "log_open('%s'): %s", logfile); + return 0; + } + + if (atexit(log_close) != 0) { + log_print(LOG_ERROR, "log_open(): atexit()"); + return 0; + } + + log_print(LOG_EVERYTIME, "=========================="); + return 1; +} diff --git a/logging.h b/logging.h new file mode 100644 index 0000000..c6e32c0 --- /dev/null +++ b/logging.h @@ -0,0 +1,16 @@ +#ifndef _LOGGING_H_ +#define _LOGGING_H_ + +#define LOG_DEBUG 5 +#define LOG_INFO 4 +#define LOG_NOTICE 3 +#define LOG_WARN 2 +#define LOG_ERROR 1 +#define LOG_CRIT 0 + +#define LOG_EVERYTIME 0 + +int log_init(char *logfile); +void log_print(int prio, const char *fmt, ... ); + +#endif /* _LOGGING_H_ */ diff --git a/network.c b/network.c new file mode 100644 index 0000000..f82dcc1 --- /dev/null +++ b/network.c @@ -0,0 +1,78 @@ +#include +#include +#include +#include +#include +#include + +#include "logging.h" + +int parse_saddr(const char *addr, struct sockaddr_in *sa) +{ + char *addr_cpy = strdup(addr); + if (addr_cpy == NULL) { + log_print(LOG_WARN, "parse_saddr(): out of memory"); + return -1; + } + + char *tmp; + char *ip = strtok_r(addr_cpy, ":", &tmp); + if (ip == NULL) { + free(addr_cpy); + return -1; + } + + char *port = strtok_r(NULL, ":", &tmp); + if (port == NULL) { + free(addr_cpy); + return -1; + } + + sa->sin_family = AF_INET; + sa->sin_port = htons(atoi(port)); + int ret = inet_aton(ip, &sa->sin_addr); + + free(addr_cpy); + return (ret != 0) ? 0 : -1; +} + +int get_sockaddr(struct sockaddr_in *sa, char *buf, int size) +{ + return snprintf(buf, size, "%s:%d", inet_ntoa(sa->sin_addr), ntohs(sa->sin_port)); +} + +char * get_sockaddr_buf(struct sockaddr_in *sa) +{ + static char buf[24]; + get_sockaddr(sa, buf, sizeof(buf)); + return buf; +} + +int tcp_listen_socket(struct sockaddr_in *sa, int cnt) +{ + int sock = socket(AF_INET, SOCK_STREAM, 0); + if (sock < 0 ) { + log_print(LOG_ERROR, "tcp_listen_socket(): socket()"); + return -1; + } + + int i = 1; + if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i))) { + log_print(LOG_ERROR, "tcp_listen_socket(): setsockopt(SO_REUSEADDR)"); + close(sock); + return -1; + } + + if (bind(sock, (struct sockaddr *)sa, sizeof(*sa))) { + log_print(LOG_ERROR, "tcp_listen_socket(): bind(%s)", get_sockaddr_buf(sa)); + close(sock); + return -1; + } + + if (listen(sock, cnt)) { + log_print(LOG_ERROR, "tcp_listen_socket(): listen()"); + close(sock); + return -1; + } + return sock; +} diff --git a/network.h b/network.h new file mode 100644 index 0000000..25923ae --- /dev/null +++ b/network.h @@ -0,0 +1,12 @@ +#ifndef _NETWORK_H_ +#define _NETWORK_H_ + +#include + +int parse_saddr(const char *addr, struct sockaddr_in *sa); +int tcp_listen_socket(struct sockaddr_in *sa, int cnt); + +int get_sockaddr(struct sockaddr_in *sa, char *buf, int size); +char * get_sockaddr_buf(struct sockaddr_in *sa); + +#endif // _NETWORK_H_ diff --git a/telnetproxy.c b/telnetproxy.c new file mode 100644 index 0000000..97cbcef --- /dev/null +++ b/telnetproxy.c @@ -0,0 +1,117 @@ +#include +#include +#include + +#include "configfile.h" +#include "connection.h" +#include "event.h" +#include "list.h" +#include "logging.h" +#include "network.h" + +static LIST_HEAD(connection_list); + +static int server_handler(int fd, void *privdata) +{ + struct connection *con = (struct connection *)privdata; + char buf[256]; + + int len = read(fd, buf, sizeof(buf)); + if (len <= 0) { + list_del(&con->list); + destroy_connection(con); + return -1; + } + + write(con->src_fd, buf, len); + return 0; +} + +static int client_handler(int fd, void *privdata) +{ + struct connection *con = (struct connection *)privdata; + char buf[256]; + + int len = read(fd, buf, sizeof(buf)); + if (len <= 0) { + list_del(&con->list); + destroy_connection(con); + return -1; + } + + if (con->dst_fd != -1) { + write(con->dst_fd, buf, len); + return 0; + } + + // check destination + int sock = tcp_connect_socket(&con->dst_addr); + if (sock < 0) { + list_del(&con->list); + destroy_connection(con); + return -1; + } + + event_add_readfd(sock, server_handler, con); + log_print(LOG_INFO, "forwarding to %s", get_sockaddr_buf(&con->dst_addr)); + return 0; +} + +static int listen_handler(int fd, void *privdata) +{ + struct connection *con = malloc(sizeof(struct connection)); + if (con == NULL) { + log_print(LOG_WARN, "listen_handler(): out of memory"); + return 0; + } + + int i = sizeof(con->src_addr); + con->src_fd = accept(fd, (struct sockaddr *)&con->src_addr, &i); + if (con->src_fd < 0) { + free(con); + return 0; + } + + con->dst_fd = -1; + con->login_time = con->idle_time = time(NULL); + + log_print(LOG_INFO, "accepted connection from %s", get_sockaddr_buf(&con->src_addr)); + + list_add_tail(&con->list, &connection_list); + event_add_readfd(con->src_fd, client_handler, con); + return 0; +} + +static int listen_init(const char *value, void *privdata) +{ + struct sockaddr_in addr; + + if (parse_saddr(value, &addr) == -1) { + log_print(LOG_WARN, "invalid listen addr: '%s'", value); + return -1; + } + + int sock = tcp_listen_socket(&addr, 10); + if (sock < 0) + return -1; + + event_add_readfd(sock, listen_handler, NULL); + log_print(LOG_INFO, "listen on %s", get_sockaddr_buf(&addr)); + return 0; +} + +int main(int argc, char *argv[]) +{ + if (config_parse("telnetproxy.conf") == -1) + return -1; + + int cnt = config_get_strings("global", "listen", listen_init, NULL); + if (cnt <= 0) { + log_print(LOG_ERROR, "no listen sockets defined!"); + return -1; + } + + event_loop(); + + return 0; +} diff --git a/telnetproxy.conf b/telnetproxy.conf new file mode 100644 index 0000000..647179e --- /dev/null +++ b/telnetproxy.conf @@ -0,0 +1,2 @@ +[global] +listen 0.0.0.0:8000