Improve LD_PRELOAD passing to children

Now it's passed even if the new process env pointer doesn't
have it, but only if it's set for ourselves. This makes
target processes starting new target processes work. Which is good.

Signed-off-by: Lauri Leukkunen <lle@rahina.org>

1 files changed, 29 insertions, 22 deletions

diff --git a/preload/sb_exec.c b/preload/sb_exec.c
index 199deaf..e602356 100644
--- a/preload/sb_exec.c
+++ b/preload/sb_exec.c
@@ -626,11 +626,15 @@ int do_exec(const char *file, char *const *argv, char *const *envp)
 {
 	char **my_envp, **my_argv, **p;
 	char *binaryname, *tmp, *my_file;
-	int envc=0, argc=0, i;
+	int envc=0, argc=0, i, has_ld_preload=0;
+
+
+	/* if we have LD_PRELOAD env var set, make sure the new my_envp
+	 * has it as well
+	 */
 
 	if (getenv("SBOX_DISABLE_MAPPING")) {
 		/* just run it, don't worry, be happy! */
-		//DBGOUT("mapping disabled\n");
 		return sb_next_execve(file, argv, envp);
 	}
 	enum binary_type type = inspect_binary(file);
@@ -641,16 +645,23 @@ int do_exec(const char *file, char *const *argv, char *const *envp)
 		binaryname = strdup(basename(file));
 	}
 
-	/* count the environment variables and arguments */
-	for (p=(char **)envp; *p; p++, envc++)
-		;
+	/* count the environment variables and arguments, also check
+	 * for LD_PRELOAD
+	 */
+	for (p=(char **)envp; *p; p++, envc++) {
+		if (strncmp("LD_PRELOAD=", *p, strlen("LD_PRELOAD=")) == 0)
+			has_ld_preload = 1;
+	}
 
 	for (p=(char **)argv; *p; p++, argc++)
 		;
 
-	//printf("envc: %i\n", envc);
+	if (has_ld_preload || !getenv("LD_PRELOAD")) {
+		my_envp = (char **)calloc(envc + 2, sizeof(char *));
+	} else {
+		my_envp = (char **)calloc(envc + 3, sizeof(char *));
+	}
 
-	my_envp = (char **)calloc(envc + 2, sizeof(char *));
 	i = strlen(binaryname) + strlen("__SB2_BINARYNAME") + 1;
 	tmp = malloc(i * sizeof(char *));
 	strcpy(tmp, "__SB2_BINARYNAME=");
@@ -673,6 +684,17 @@ int do_exec(const char *file, char *const *argv, char *const *envp)
 
 	my_envp[i++] = strdup(tmp);
 	free(tmp);
+	if (!has_ld_preload && getenv("LD_PRELOAD")) {
+		tmp = malloc(strlen(getenv("LD_PRELOAD")) 
+				+ strlen("LD_PRELOAD=") + 1);
+		if (!tmp)
+			exit(1);
+		strcpy(tmp, "LD_PRELOAD=");
+		strcat(tmp, getenv("LD_PRELOAD"));
+		my_envp[i++] = strdup(tmp);
+		free(tmp);
+	}
+
 	my_envp[i] = NULL;
 
 	char const* const* new_env=(char const* const*)my_envp;
@@ -691,8 +713,6 @@ int do_exec(const char *file, char *const *argv, char *const *envp)
 		} else {
 			my_file = strdup(sb_gcc_wrapper);
 		}
-		/*DBGOUT("we've a gcc tool!\n");*/
-		//my_argv[i++] = strdup(binaryname);
 	}
 
 	for (p = (char **)argv; *p; p++) {
@@ -700,7 +720,6 @@ int do_exec(const char *file, char *const *argv, char *const *envp)
 	}
 	my_argv[i] = NULL;
 
-	/* printf("type: %i\n", type);*/ 
 	switch (type) {
 		case BIN_FOREIGN:
 			new_env = drop_preload(my_envp);
@@ -719,7 +738,6 @@ int do_exec(const char *file, char *const *argv, char *const *envp)
 				}
 			}
 		case BIN_TARGET:
-			/* DBGOUT("cpu transparency needed\n"); */
 			return run_cputransparency(my_file, (char **)my_argv, my_envp);
 
 		case BIN_NONE:
@@ -732,14 +750,3 @@ int do_exec(const char *file, char *const *argv, char *const *envp)
 	return sb_next_execve(my_file, my_argv, (char *const*)new_env);
 }
 
-
-#if 0
-void scratchbox_init (void) __attribute((constructor));
-void scratchbox_init (void)
-{
-	/* currently doing nothing */
-	DBGOUT("in scratchbox_init\n");
-}
-#endif
-
-