X-Git-Url: https://ruderich.org/simon/gitweb/?p=coloredstderr%2Fcoloredstderr.git;a=blobdiff_plain;f=src%2Fcoloredstderr.c;h=4664f0d1a8d0efb033fb11bf28814fc4a730d12c;hp=0d76b5aee7dd0799c40e1ccf82b313e3f4002221;hb=2241f5278e786c429b8d657c807ead792b4b5b36;hpb=e5a94fa847f4d880eb42f53bd93131ccf9fabe03 diff --git a/src/coloredstderr.c b/src/coloredstderr.c index 0d76b5a..4664f0d 100644 --- a/src/coloredstderr.c +++ b/src/coloredstderr.c @@ -36,8 +36,12 @@ #include #include #include +#include #include +#ifdef HAVE_ERR_H +# include +#endif #ifdef HAVE_ERROR_H # include #endif @@ -45,13 +49,23 @@ # include #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. */ +/* The following functions may be macros. Undefine them or they cause build + * failures when used in our hook macros below. */ + +/* In glibc, real fwrite_unlocked() is called in macro. */ +#ifdef HAVE_FWRITE_UNLOCKED +# undef fwrite_unlocked +#endif +/* 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(). */ @@ -64,6 +78,15 @@ static size_t (*real_fwrite)(void const *, size_t, size_t, FILE *); 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" @@ -164,6 +187,10 @@ static void handle_file_pre(FILE *stream) noinline; 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)) { @@ -176,6 +203,10 @@ static void handle_fd_pre(int fd) { 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(). */ @@ -185,6 +216,10 @@ static void handle_fd_post(int fd) { } static void handle_file_pre(FILE *stream) { + if (handle_recursive++ > 0) { + return; + } + int saved_errno = errno; if (unlikely(!pre_string || !post_string)) { @@ -197,6 +232,10 @@ static void handle_file_pre(FILE *stream) { 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(). */ @@ -221,6 +260,14 @@ HOOK_FILE2(int, fputc, stream, 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, @@ -246,26 +293,72 @@ HOOK_FILE4(int, __vfprintf_chk, stream, FILE *, stream, int, flag, char const *, format, va_list, ap) /* unlocked_stdio(3), only functions from above are hooked */ +#ifdef HAVE_FWRITE_UNLOCKED HOOK_FILE4(size_t, fwrite_unlocked, stream, void const *, ptr, size_t, size, size_t, nmemb, FILE *, stream) +#endif +#ifdef HAVE_FPUTS_UNLOCKED HOOK_FILE2(int, fputs_unlocked, stream, char const *, s, FILE *, stream) +#endif +#ifdef HAVE_FPUTC_UNLOCKED HOOK_FILE2(int, fputc_unlocked, stream, int, c, FILE *, stream) +#endif HOOK_FILE2(int, putc_unlocked, stream, int, c, FILE *, stream) HOOK_FILE1(int, putchar_unlocked, stdout, int, c) -/* 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) +/* glibc defines (_IO_)putc_unlocked() to a macro which either updates the + * output buffer or calls __overflow(). As this code is inlined we can't + * handle the first case, but if __overflow() is called we can color that + * 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). */ +#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, char const *, s) -/* error(3) */ +/* err(3), non standard BSD extension */ +#ifdef HAVE_ERR_H +HOOK_VAR_VOID2(void, err, STDERR_FILENO, verr, + int, eval, char const *, fmt) +HOOK_VAR_VOID2(void, errx, STDERR_FILENO, verrx, + int, eval, char const *, fmt) +HOOK_VAR_VOID1(void, warn, STDERR_FILENO, vwarn, + char const *, fmt) +HOOK_VAR_VOID1(void, warnx, STDERR_FILENO, vwarnx, + char const *, fmt) +HOOK_FUNC_SIMPLE3(void, verr, int, eval, const char *, fmt, va_list, args) { + /* Can't use verr() directly as it terminates the process which prevents + * the post string from being printed. */ + vwarn(fmt, args); + exit(eval); +} +HOOK_FUNC_SIMPLE3(void, verrx, int, eval, const char *, fmt, va_list, args) { + /* See verr(). */ + vwarnx(fmt, args); + exit(eval); +} +HOOK_VOID2(void, vwarn, STDERR_FILENO, + char const *, fmt, va_list, args) +HOOK_VOID2(void, vwarnx, STDERR_FILENO, + char const *, fmt, va_list, args) +#endif + +/* error(3), non-standard GNU extension */ #ifdef HAVE_ERROR_H static void error_vararg(int status, int errnum, char const *filename, unsigned int linenum, @@ -336,44 +429,44 @@ void error(int status, int errnum, char const *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) { + if (newfd > -1) { dup_fd(oldfd, newfd); } 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) { + if (newfd > -1) { dup_fd(oldfd, newfd); } 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) { + if (newfd > -1) { dup_fd(oldfd, newfd); } 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; @@ -397,15 +490,15 @@ int fcntl(int fd, int cmd, ...) { 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); } 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"); if (fd >= 0) { @@ -413,8 +506,8 @@ int close(int 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"); @@ -448,34 +541,23 @@ pid_t vfork(void) { /* 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. */ -static int (*real_execve)(char const *filename, char * const argv[], char * const env[]); -int execve(char const *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; - 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 @@ -484,17 +566,40 @@ int execve(char const *filename, char * const argv[], char * const env[]) { 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); @@ -507,14 +612,14 @@ int execve(char const *filename, char * const argv[], char * const env[]) { /* Count arguments. */ \ size_t count = 1; /* arg */ \ va_start(ap, arg); \ - while (va_arg(ap, char const *)) { \ + 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); \ @@ -552,16 +657,16 @@ int execle(char const *path, char const *arg, ... /*, char * const envp[] */) { return execve(path, args, envp); } -static int (*real_execv)(char const *path, char * const argv[]); -int execv(char const *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)(char const *path, char * const argv[]); -int execvp(char const *file, 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(); @@ -571,10 +676,16 @@ int execvp(char const *file, char * const argv[]) { #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