/* In Clang when compiling with hardening flags (fortify) on Debian Wheezy. */
#undef printf
#undef fprintf
+/* On FreeBSD (9.1), __swbuf() is used instead of these macros. */
+#ifdef HAVE___SWBUF
+# undef putc
+# undef putc_unlocked
+# undef putchar
+# undef putchar_unlocked
+#endif
/* Used by various functions, including debug(). */
static int initialized;
/* Force hooked writes even when not writing to a tty. Used for tests. */
static int force_write_to_non_tty;
+/* Was ENV_NAME_FDS found and used when init_from_environment() was called?
+ * This is not true if the process set it manually after initialization. */
+static int used_fds_set_by_user;
+/* Was any of our handle_*_pre()/handle_*_post() functions called recursively?
+ * If so don't print the pre/post string for the recursive calls. This is
+ * necessary on some systems (e.g. FreeBSD 9.1) which call multiple hooked
+ * functions while printing a string (e.g. a FILE * and a fd hook function is
+ * called). */
+static int handle_recursive;
#include "constants.h"
static void handle_file_post(FILE *stream) noinline;
static void handle_fd_pre(int fd) {
+ if (handle_recursive++ > 0) {
+ return;
+ }
+
int saved_errno = errno;
if (unlikely(!pre_string || !post_string)) {
errno = saved_errno;
}
static void handle_fd_post(int fd) {
+ if (--handle_recursive > 0) {
+ return;
+ }
+
int saved_errno = errno;
/* write() already loaded above in handle_fd_pre(). */
}
static void handle_file_pre(FILE *stream) {
+ if (handle_recursive++ > 0) {
+ return;
+ }
+
int saved_errno = errno;
if (unlikely(!pre_string || !post_string)) {
errno = saved_errno;
}
static void handle_file_post(FILE *stream) {
+ if (--handle_recursive > 0) {
+ return;
+ }
+
int saved_errno = errno;
/* fwrite() already loaded above in handle_file_pre(). */
int, c, FILE *, stream)
HOOK_FILE2(int, putc, stream,
int, c, FILE *, stream)
+/* The glibc uses a macro for putc() which expands to _IO_putc(). However
+ * sometimes the raw putc() is used as well, not sure why. Make sure to hook
+ * it too. */
+#ifdef putc
+# undef putc
+HOOK_FILE2(int, putc, stream,
+ int, c, FILE *, stream)
+#endif
HOOK_FILE1(int, putchar, stdout,
int, c)
HOOK_FILE1(int, puts, stdout,
* part. As writes to stderr are never buffered, __overflow() is always called
* and everything works fine. This is only a problem if stdout is dupped to
* stderr (which shouldn't be the case too often). */
-#ifdef HAVE_STRUCT__IO_FILE__FILENO
+#if defined(HAVE_STRUCT__IO_FILE__FILENO) && defined(HAVE___OVERFLOW)
/* _IO_FILE is glibc's representation of FILE. */
HOOK_FILE2(int, __overflow, f, _IO_FILE *, f, int, ch)
#endif
+/* Same for FreeBSD's libc. However it's more aggressive: The inline writing
+ * and __swbuf() are also used for normal output (e.g. putc()). Writing to
+ * stderr is still fine; it always calls __swbuf() as stderr is always
+ * unbufferd. */
+#ifdef HAVE___SWBUF
+HOOK_FILE2(int, __swbuf, f, int, c, FILE *, f)
+#endif
/* perror(3) */
HOOK_VOID1(void, perror, STDERR_FILENO,
DLSYM_FUNCTION(real_dup, "dup");
newfd = real_dup(oldfd);
- if (newfd != -1) {
+ if (newfd > -1) {
dup_fd(oldfd, newfd);
}
DLSYM_FUNCTION(real_dup2, "dup2");
newfd = real_dup2(oldfd, newfd);
- if (newfd != -1) {
+ if (newfd > -1) {
dup_fd(oldfd, newfd);
}
DLSYM_FUNCTION(real_dup3, "dup3");
newfd = real_dup3(oldfd, newfd, flags);
- if (newfd != -1) {
+ if (newfd > -1) {
dup_fd(oldfd, newfd);
}
va_end(ap);
/* We only care about duping fds. */
- if (cmd == F_DUPFD && result != -1) {
+ if (cmd == F_DUPFD && result > -1) {
dup_fd(fd, result);
}
/* Hook execve() and the other exec*() functions. Some shells use exec*() with
* a custom environment which doesn't necessarily contain our updates to
- * 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. */
+ * ENV_NAME_PRIVATE_FDS. It's also faster to update the environment only when
+ * necessary, right before the exec(), to pass it to the new program. */
/* 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;
- size_t index = 0;
-
- /* Count arguments and search for existing ENV_NAME_FDS environment
- * variable. */
+ /* Count environment variables. */
size_t count = 0;
char * const *x = env;
- while (*x) {
- if (!strncmp(*x, ENV_NAME_FDS "=", strlen(ENV_NAME_FDS) + 1)) {
- found = 1;
- index = count;
- }
-
- x++;
+ while (*x++) {
count++;
}
/* Terminating NULL. */
count++;
char *env_copy[count + 1 /* space for our new entry if necessary */];
- memcpy(env_copy, env, count * sizeof(char *));
/* Make sure the information from the environment is loaded. We can't just
* do nothing (like update_environment()) because the caller might pass a
init_from_environment();
}
- char fds_env[strlen(ENV_NAME_FDS) + 1 + update_environment_buffer_size()];
- strcpy(fds_env, ENV_NAME_FDS "=");
- update_environment_buffer(fds_env + strlen(ENV_NAME_FDS) + 1);
+ char fds_env[strlen(ENV_NAME_PRIVATE_FDS)
+ + 1 + update_environment_buffer_size()];
+ strcpy(fds_env, ENV_NAME_PRIVATE_FDS "=");
+ update_environment_buffer(fds_env + strlen(ENV_NAME_PRIVATE_FDS) + 1);
- if (found) {
- env_copy[index] = fds_env;
- } else {
- /* If the process removed ENV_NAME_FDS from the environment, re-add
- * it. */
- env_copy[count-1] = fds_env;
- env_copy[count] = NULL;
+ int found = 0;
+ char **x_copy = env_copy;
+
+ /* Copy the environment manually; allows skipping elements. */
+ x = env;
+ while ((*x_copy = *x)) {
+ /* Remove ENV_NAME_FDS if we've already used its value. The new
+ * program must use the updated list from ENV_NAME_PRIVATE_FDS. */
+ if (used_fds_set_by_user
+ && !strncmp(*x, ENV_NAME_FDS "=", strlen(ENV_NAME_FDS) + 1)) {
+ x++;
+ continue;
+ /* Update ENV_NAME_PRIVATE_FDS. */
+ } else if (!strncmp(*x, ENV_NAME_PRIVATE_FDS "=",
+ strlen(ENV_NAME_PRIVATE_FDS) + 1)) {
+ *x_copy = fds_env;
+ found = 1;
+ }
+
+ x++;
+ x_copy++;
+ }
+ /* The loop "condition" NULL-terminates env_copy. */
+
+ if (!found) {
+ /* If the process removed ENV_NAME_PRIVATE_FDS from the environment,
+ * re-add it. */
+ *x_copy++ = fds_env;
+ *x_copy++ = NULL;
}
return real_execve(filename, argv, env_copy);
#ifdef HAVE_EXECVPE
extern char **environ;
int execvpe(char const *file, char * const argv[], char * const envp[]) {
+ int result;
+ char **old_environ = environ;
+
/* Fake the environment so we can reuse execvp(). */
environ = (char **)envp;
/* execvp() updates the environment. */
- return execvp(file, argv);
+ result = execvp(file, argv);
+
+ environ = old_environ;
+ return result;
}
#endif
ruderich.org/simon / coloredstderr / coloredstderr.git / blobdiff