#include <config.h>
+#include "compiler.h"
+
/* Must be loaded before the following headers. */
#include "ldpreload.h"
+/* Disable assert()s if not compiled with --enable-debug. */
+#ifndef DEBUG
+# define NDEBUG
+#endif
+
+#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#ifdef HAVE_ERROR_H
# include <error.h>
#endif
+#ifdef HAVE_STRUCT__IO_FILE__FILENO
+# include <libio.h>
+#endif
/* Conflicting declaration in glibc. */
#undef fwrite_unlocked
+/* These functions may be macros when compiling with hardening flags (fortify)
+ * which cause build failures when used in our hook macros below. Observed
+ * with Clang on Debian Wheezy. */
+#undef printf
+#undef fprintf
/* Used by various functions, including debug(). */
-static ssize_t (*real_write)(int, const void *, size_t);
+static ssize_t (*real_write)(int, void const *, size_t);
static int (*real_close)(int);
-static size_t (*real_fwrite)(const void *, size_t, size_t, FILE *);
+static size_t (*real_fwrite)(void const *, size_t, size_t, FILE *);
/* Did we already (try to) parse the environment and setup the necessary
* variables? */
#include "constants.h"
-#ifdef DEBUG
+#ifdef WARNING
# include "debug.h"
#endif
-/* Should the "action" handler be invoked for this file descriptor? */
-static int check_handle_fd(int fd) {
- /* Load state from environment. Only necessary once per process. */
- if (!initialized) {
- init_from_environment();
- }
- if (tracked_fds_count == 0) {
- return 0;
- }
+/* See hookmacros.h for the decision if a function call is colored. */
- /* Never touch anything not going to a terminal - unless we are explicitly
- * asked to do so. */
- if (!force_write_to_non_tty && !isatty(fd)) {
- return 0;
- }
- return tracked_fds_find(fd);
+/* Prevent inlining into hook functions because it may increase the number of
+ * spilled registers unnecessarily. As it's not called very often accept the
+ * additional call. */
+static int isatty_noinline(int fd) noinline;
+static int isatty_noinline(int fd) {
+ assert(fd >= 0);
+
+ int saved_errno = errno;
+ int result = isatty(fd);
+ errno = saved_errno;
+
+ return result;
}
+
static void dup_fd(int oldfd, int newfd) {
#ifdef DEBUG
debug("%3d -> %3d\t\t\t[%d]\n", oldfd, newfd, getpid());
#endif
- if (!initialized) {
+ assert(oldfd >= 0 && newfd >= 0);
+
+ if (unlikely(!initialized)) {
init_from_environment();
}
- if (tracked_fds_count == 0) {
- return;
- }
/* We are already tracking this file descriptor, add newfd to the list as
* it will reference the same descriptor. */
debug("%3d -> .\t\t\t[%d]\n", fd, getpid());
#endif
- if (!initialized) {
+ assert(fd >= 0);
+
+ if (unlikely(!initialized)) {
init_from_environment();
}
- if (tracked_fds_count == 0) {
- return;
- }
tracked_fds_remove(fd);
}
/* "Action" handlers called when a file descriptor is matched. */
-static char *pre_string;
+static char const *pre_string;
static size_t pre_string_size;
-static char *post_string;
+static char const *post_string;
static size_t post_string_size;
/* Load alternative pre/post strings from the environment if available, fall
* back to default values. */
-inline static void init_pre_post_string() {
+static void init_pre_post_string(void) {
pre_string = getenv(ENV_NAME_PRE_STRING);
if (!pre_string) {
pre_string = DEFAULT_PRE_STRING;
post_string_size = strlen(post_string);
}
-static void handle_fd_pre(int fd, int action) {
- (void)action;
+/* Don't inline any of the pre/post functions. Keep the hook function as small
+ * as possible for speed reasons. */
+static void handle_fd_pre(int fd) noinline;
+static void handle_fd_post(int fd) noinline;
+static void handle_file_pre(FILE *stream) noinline;
+static void handle_file_post(FILE *stream) noinline;
+
+static void handle_fd_pre(int fd) {
+ int saved_errno = errno;
- if (!pre_string || !post_string) {
+ if (unlikely(!pre_string || !post_string)) {
init_pre_post_string();
}
DLSYM_FUNCTION(real_write, "write");
real_write(fd, pre_string, pre_string_size);
+
+ errno = saved_errno;
}
-static void handle_fd_post(int fd, int action) {
- (void)action;
+static void handle_fd_post(int fd) {
+ int saved_errno = errno;
/* write() already loaded above in handle_fd_pre(). */
real_write(fd, post_string, post_string_size);
+
+ errno = saved_errno;
}
-static void handle_file_pre(FILE *stream, int action) {
- (void)action;
+static void handle_file_pre(FILE *stream) {
+ int saved_errno = errno;
- if (!pre_string || !post_string) {
+ if (unlikely(!pre_string || !post_string)) {
init_pre_post_string();
}
DLSYM_FUNCTION(real_fwrite, "fwrite");
real_fwrite(pre_string, pre_string_size, 1, stream);
+
+ errno = saved_errno;
}
-static void handle_file_post(FILE *stream, int action) {
- (void)action;
+static void handle_file_post(FILE *stream) {
+ int saved_errno = errno;
/* fwrite() already loaded above in handle_file_pre(). */
real_fwrite(post_string, post_string_size, 1, stream);
+
+ errno = saved_errno;
}
/* Hook all important output functions to manipulate their output. */
HOOK_FD3(ssize_t, write, fd,
- int, fd, const void *, buf, size_t, count)
+ int, fd, void const *, buf, size_t, count)
HOOK_FILE4(size_t, fwrite, stream,
- const void *, ptr, size_t, size, size_t, nmemb, FILE *, stream)
+ void const *, ptr, size_t, size, size_t, nmemb, FILE *, stream)
/* puts(3) */
HOOK_FILE2(int, fputs, stream,
- const char *, s, FILE *, stream)
+ char const *, s, FILE *, stream)
HOOK_FILE2(int, fputc, stream,
int, c, FILE *, stream)
HOOK_FILE2(int, putc, stream,
HOOK_FILE1(int, putchar, stdout,
int, c)
HOOK_FILE1(int, puts, stdout,
- const char *, s)
+ char const *, s)
/* printf(3), excluding all s*() and vs*() functions (no output) */
HOOK_VAR_FILE1(int, printf, stdout, vprintf,
- const char *, format)
+ char const *, format)
HOOK_VAR_FILE2(int, fprintf, stream, vfprintf,
- FILE *, stream, const char *, format)
+ FILE *, stream, char const *, format)
HOOK_FILE2(int, vprintf, stdout,
- const char *, format, va_list, ap)
+ char const *, format, va_list, ap)
HOOK_FILE3(int, vfprintf, stream,
- FILE *, stream, const char *, format, va_list, ap)
+ FILE *, stream, char const *, format, va_list, ap)
/* Hardening functions (-D_FORTIFY_SOURCE=2), only functions from above */
HOOK_VAR_FILE2(int, __printf_chk, stdout, __vprintf_chk,
- int, flag, const char *, format)
+ int, flag, char const *, format)
HOOK_VAR_FILE3(int, __fprintf_chk, fp, __vfprintf_chk,
- FILE *, fp, int, flag, const char *, format)
+ FILE *, fp, int, flag, char const *, format)
HOOK_FILE3(int, __vprintf_chk, stdout,
- int, flag, const char *, format, va_list, ap)
+ int, flag, char const *, format, va_list, ap)
HOOK_FILE4(int, __vfprintf_chk, stream,
- FILE *, stream, int, flag, const char *, format, va_list, ap)
+ FILE *, stream, int, flag, char const *, format, va_list, ap)
/* unlocked_stdio(3), only functions from above are hooked */
HOOK_FILE4(size_t, fwrite_unlocked, stream,
- const void *, ptr, size_t, size, size_t, nmemb, FILE *, stream)
+ void const *, ptr, size_t, size, size_t, nmemb, FILE *, stream)
HOOK_FILE2(int, fputs_unlocked, stream,
- const char *, s, FILE *, stream)
+ char const *, s, FILE *, stream)
HOOK_FILE2(int, fputc_unlocked, stream,
int, c, FILE *, stream)
HOOK_FILE2(int, putc_unlocked, stream,
int, c, FILE *, stream)
HOOK_FILE1(int, putchar_unlocked, stdout,
int, c)
-HOOK_FILE1(int, puts_unlocked, stdout,
- const char *, s)
+/* glibc defines (_IO_)putc_unlocked() to __overflow() in some cases. */
+#ifdef HAVE_STRUCT__IO_FILE__FILENO
+HOOK_FD2(int, __overflow, f->_fileno, _IO_FILE *, f, int, ch)
+#endif
/* perror(3) */
HOOK_VOID1(void, perror, STDERR_FILENO,
- const char *, s)
+ char const *, s)
/* error(3) */
#ifdef HAVE_ERROR_H
-static void error_vararg(int status, int errnum,
- const char *filename, unsigned int linenum,
- const char *format, va_list ap) {
- static const char *last_filename;
+static void error_vararg(int status, int errnum,
+ char const *filename, unsigned int linenum,
+ char const *format, va_list ap) {
+ static char const *last_filename;
static unsigned int last_linenum;
/* Skip this error message if requested and if there was already an error
}
}
void error_at_line(int status, int errnum,
- const char *filename, unsigned int linenum,
- const char *format, ...) {
+ char const *filename, unsigned int linenum,
+ char const *format, ...) {
va_list ap;
va_start(ap, format);
error_vararg(status, errnum, filename, linenum, format, ap);
va_end(ap);
}
-void error(int status, int errnum, const char *format, ...) {
+void error(int status, int errnum, char const *format, ...) {
va_list ap;
va_start(ap, format);
/* Hook functions which duplicate file descriptors to track them. */
-static int (*real_dup)(int);
-static int (*real_dup2)(int, int);
-static int (*real_dup3)(int, int, int);
-int dup(int oldfd) {
+/* int dup(int) */
+HOOK_FUNC_DEF1(int, dup, int, oldfd) {
int newfd;
DLSYM_FUNCTION(real_dup, "dup");
newfd = real_dup(oldfd);
if (newfd != -1) {
- int saved_errno = errno;
dup_fd(oldfd, newfd);
- errno = saved_errno;
}
return newfd;
}
-int dup2(int oldfd, int newfd) {
+/* int dup2(int, int) */
+HOOK_FUNC_DEF2(int, dup2, int, oldfd, int, newfd) {
DLSYM_FUNCTION(real_dup2, "dup2");
newfd = real_dup2(oldfd, newfd);
if (newfd != -1) {
- int saved_errno = errno;
dup_fd(oldfd, newfd);
- errno = saved_errno;
}
return newfd;
}
-int dup3(int oldfd, int newfd, int flags) {
+/* int dup3(int, int, int) */
+HOOK_FUNC_DEF3(int, dup3, int, oldfd, int, newfd, int, flags) {
DLSYM_FUNCTION(real_dup3, "dup3");
newfd = real_dup3(oldfd, newfd, flags);
if (newfd != -1) {
- int saved_errno = errno;
dup_fd(oldfd, newfd);
- errno = saved_errno;
}
return newfd;
}
-static int (*real_fcntl)(int, int, ...);
-int fcntl(int fd, int cmd, ...) {
+/* int fcntl(int, int, ...) */
+HOOK_FUNC_VAR_DEF2(int, fcntl, int, fd, int, cmd /*, ... */) {
int result;
va_list ap;
/* We only care about duping fds. */
if (cmd == F_DUPFD && result != -1) {
- int saved_errno = errno;
dup_fd(fd, result);
- errno = saved_errno;
}
return result;
}
-static int (*real_close)(int);
-int close(int fd) {
+/* int close(int) */
+HOOK_FUNC_DEF1(int, close, int, fd) {
DLSYM_FUNCTION(real_close, "close");
- close_fd(fd);
+ if (fd >= 0) {
+ close_fd(fd);
+ }
return real_close(fd);
}
-static int (*real_fclose)(FILE *);
-int fclose(FILE *fp) {
+/* int fclose(FILE *) */
+HOOK_FUNC_DEF1(int, fclose, FILE *, fp) {
+ int fd;
+
DLSYM_FUNCTION(real_fclose, "fclose");
- close_fd(fileno(fp));
+ if (fp != NULL && (fd = fileno(fp)) >= 0) {
+ close_fd(fd);
+ }
return real_fclose(fp);
}
* ENV_NAME_FDS. It's also faster to update the environment only when
* necessary, right before the exec() to pass it to the new process. */
-static int (*real_execve)(const char *filename, char *const argv[], char *const env[]);
-int execve(const char *filename, char *const argv[], char *const env[]) {
+/* int execve(char const *, char * const [], char * const []) */
+HOOK_FUNC_DEF3(int, execve, char const *, filename, char * const *, argv, char * const *, env) {
DLSYM_FUNCTION(real_execve, "execve");
int found = 0;
/* Count arguments. */ \
size_t count = 1; /* arg */ \
va_start(ap, arg); \
- while (va_arg(ap, const char *)) { \
+ while (va_arg(ap, char *)) { \
count++; \
} \
va_end(ap); \
\
/* Copy varargs. */ \
char *args[count + 1 /* terminating NULL */]; \
- args[0] = (char *)arg; \
+ args[0] = (char *)arg; /* there's no other way around the cast */ \
\
size_t i = 1; \
va_start(ap, arg); \
EXECL_COPY_VARARGS_START(args); \
EXECL_COPY_VARARGS_END(args);
-int execl(const char *path, const char *arg, ...) {
+int execl(char const *path, char const *arg, ...) {
EXECL_COPY_VARARGS(args);
- update_environment();
+ /* execv() updates the environment. */
return execv(path, args);
}
-
-int execlp(const char *file, const char *arg, ...) {
+int execlp(char const *file, char const *arg, ...) {
EXECL_COPY_VARARGS(args);
- update_environment();
+ /* execvp() updates the environment. */
return execvp(file, args);
}
+int execle(char const *path, char const *arg, ... /*, char * const envp[] */) {
+ char * const *envp;
-int execle(const char *path, const char *arg, ... /*, char *const envp[] */) {
EXECL_COPY_VARARGS_START(args);
/* Get envp[] located after arguments. */
- char * const *envp = va_arg(ap, char * const *);
+ envp = va_arg(ap, char * const *);
EXECL_COPY_VARARGS_END(args);
+ /* execve() updates the environment. */
return execve(path, args, envp);
}
-static int (*real_execv)(const char *path, char *const argv[]);
-int execv(const char *path, char *const argv[]) {
+/* int execv(char const *, char * const []) */
+HOOK_FUNC_DEF2(int, execv, char const *, path, char * const *, argv) {
DLSYM_FUNCTION(real_execv, "execv");
update_environment();
return real_execv(path, argv);
}
-static int (*real_execvp)(const char *path, char *const argv[]);
-int execvp(const char *path, char *const argv[]) {
+/* int execvp(char const *, char * const []) */
+HOOK_FUNC_DEF2(int, execvp, char const *, file, char * const *, argv) {
DLSYM_FUNCTION(real_execvp, "execvp");
update_environment();
- return real_execvp(path, argv);
+ return real_execvp(file, argv);
}
+
+#ifdef HAVE_EXECVPE
+extern char **environ;
+int execvpe(char const *file, char * const argv[], char * const envp[]) {
+ /* Fake the environment so we can reuse execvp(). */
+ environ = (char **)envp;
+
+ /* execvp() updates the environment. */
+ return execvp(file, argv);
+}
+#endif