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This commit is contained in:
Olaf Rempel 2006-11-25 14:31:52 +01:00
commit 78ecedcc4e
15 changed files with 1201 additions and 0 deletions
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3
.gitignore vendored Normal file
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*.d
*.o
telnetproxy

22
Makefile Normal file
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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)

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/***************************************************************************
* 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#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(&section->list);
INIT_LIST_HEAD(&section->tupel_list);
section->name = strdup(name);
if (section->name == NULL) {
free(section);
return NULL;
}
list_add_tail(&section->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, &section->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, &section->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, &section->tupel_list, list) {
if (!strcmp(tupel->option, option))
if (callback(tupel->parameter, privdata) == 0)
cnt++;
}
return cnt;
}

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#ifndef _CONFIG_H_
#define _CONFIG_H_
#include <netinet/in.h>
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_ */

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#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include "connection.h"

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connection.h Normal file
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#ifndef _CONNECTION_H_
#define _CONNECTION_H_
#include <netinet/ip.h>
#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_

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/***************************************************************************
* 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 <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/time.h>
#include <sys/types.h>
#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);
}
}
}
}
}

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#ifndef _EVENT_H_
#define _EVENT_H_
#include <sys/time.h>
#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_ */

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#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 <razzor@kopf-tisch.de>
*/
#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_ */

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/***************************************************************************
* 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 <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <stdarg.h>
#include <errno.h>
#include <string.h>
#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;
}

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#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_ */

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#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#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;
}

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#ifndef _NETWORK_H_
#define _NETWORK_H_
#include <netinet/ip.h>
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_

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#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#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;
}

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telnetproxy.conf Normal file
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[global]
listen 0.0.0.0:8000