X-Git-Url: https://ruderich.org/simon/gitweb/?p=coloredstderr%2Fcoloredstderr.git;a=blobdiff_plain;f=src%2Fcoloredstderr.c;h=4664f0d1a8d0efb033fb11bf28814fc4a730d12c;hp=00de8a588b080cee6b37d968f8641df954bd0544;hb=2241f5278e786c429b8d657c807ead792b4b5b36;hpb=045ca46e7929c27c3c408324aaae02499b1eae81

diff --git a/src/coloredstderr.c b/src/coloredstderr.c
index 00de8a5..4664f0d 100644
--- a/src/coloredstderr.c
+++ b/src/coloredstderr.c
@@ -78,6 +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"
@@ -178,6 +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)) {
@@ -190,6 +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(). */
@@ -199,6 +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)) {
@@ -211,6 +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(). */
@@ -235,6 +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,
@@ -403,7 +436,7 @@ HOOK_FUNC_DEF1(int, dup, int, oldfd) {
     DLSYM_FUNCTION(real_dup, "dup");
 
     newfd = real_dup(oldfd);
-    if (newfd != -1) {
+    if (newfd > -1) {
         dup_fd(oldfd, newfd);
     }
 
@@ -414,7 +447,7 @@ 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);
     }
 
@@ -425,7 +458,7 @@ 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);
     }
 
@@ -457,7 +490,7 @@ HOOK_FUNC_VAR_DEF2(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);
     }
 
@@ -508,34 +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. */
 
 /* 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
@@ -544,17 +566,40 @@ HOOK_FUNC_DEF3(int, execve, char const *, filename, char * const *, argv, char *
         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);
@@ -631,10 +676,16 @@ HOOK_FUNC_DEF2(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