Changed exec parameter to improve error treatment

src/environment.c

@@ -1,20 +1,71 @@
+#include "sandbox.h"
 #include <sys/stat.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 #include <errno.h>
 #include <time.h>
-#include "sandbox.h"
 
-int init_env(t_param *params)
+static char *check_file(const char *fname)
 {
-	char * path = params->tmppath = (char *) malloc(sizeof(*path) * (strlen(params->tmpdir) + 24));
+	const char *pos;
+	char *path = getenv("PATH");
+	char *dir;
+	char *fullpath = NULL;
+	int fullpath_len;
+	struct stat cmd_stat;
+
+	for (pos = fname; *pos && *pos != '/'; ++pos);
+	if (*pos && (stat(fname, &cmd_stat) == -1))
+	{
+		fprintf(stderr, "Cannot stat %s: %s\n", fname, strerror(errno));
+		return NULL;
+	}
+	else if (!*pos && !path)
+	{
+		fprintf(stderr, "Cannot stat %s: No such file or directory\n", fname);
+		return NULL;
+	}
+	if (!*pos)
+		for ((dir = strtok(path, ":")); dir; dir = strtok(NULL, ":"))
+		{
+			int len = strlen(dir);
+			if (fullpath == NULL || fullpath_len < len)
+			{
+				if (fullpath)
+					fullpath = realloc(fullpath, sizeof(*fullpath) * (strlen(fname) + 2 + len));
+				else
+					fullpath = malloc(sizeof(*fullpath) * (strlen(fname) + len +2));
+				fullpath_len = len;
+			}
+			sprintf(fullpath, "%s/%s", dir, fname);
+			if (stat(fullpath, &cmd_stat) != -1 && !S_ISDIR(cmd_stat.st_mode))
+				return fullpath;
+		}
+	if (S_ISDIR(cmd_stat.st_mode))
+	{
+		fprintf(stderr, "Cannot execute %s: is a directory\n", fname);
+		return NULL;
+	}
+	if (!fullpath && *pos)
+		fullpath = strdup(fname);
+	else if (!*pos)
+	{
+		free(fullpath);
+		fprintf(stderr, "Cannot execute %s: command not found\n", fname);
+		fullpath = NULL;
+	}
+	return fullpath;
+}
 
-	/* TODO check if prog name exists */
-	sprintf(path, "%s/sandbox_%ld:%d", params->tmpdir, time(NULL), getpid());
-	if (mkdir(path, 0) == -1)
+int init_env(t_param *params)
+{
+	if ((params->cmdpath = check_file(params->cmd[0])) == NULL)
+		return -1;
+	asprintf(&(params->tmppath), "%s/sandbox_%ld:%d", params->tmpdir, time(NULL), getpid());
+	if (mkdir(params->tmppath, 0) == -1)
 	{
-		fprintf(stderr, "Cannot create directory %s: %s\n", path, strerror(errno));
+		fprintf(stderr, "Cannot create directory %s: %s\n", params->tmppath, strerror(errno));
 		return -1;
 	}
 	return 0;
@@ -25,6 +76,7 @@ void release_env(t_param *params)
 	rmdir(params->tmppath);
 
 	free(params->tmppath);
+	free(params->cmdpath);
 	free(params);
 }
 

src/exec.c

@@ -7,7 +7,7 @@ void doExec(int pid_parent, const t_param *params)
 {
 	char **argv = (char **)params->cmd;
 
-	execvp(argv[0], argv);
+	execv(params->cmdpath, argv);
 	fprintf(stderr, "Error: %s\n", strerror(errno));
 }
 

src/mem.c

@@ -1,7 +1,7 @@
+#include "sandbox.h"
 #include <sys/uio.h>
 #include <stdlib.h>
 #include <string.h>
-#include "sandbox.h"
 
 static inline size_t process_vm_read(int pid, struct iovec *local, struct iovec *remote)
 {

src/sandbox.c

@@ -56,7 +56,10 @@ int manageSyscall(struct s_sandboxenv *env)
 
 	if (syscall_nr >= NR_syscalls ||
 			!(ovr_fnc = env->functions[syscall_nr]))
+	{
+		/* TODO verbose -v */
 		return 0;
+	}
 	get_args(env);
 	(ovr_fnc)(env);
 	return 1;

src/sandbox.h

@@ -1,6 +1,8 @@
 #ifndef   SANDBOX_H__
 # define  SANDBOX_H__
 
+#define _GNU_SOURCE
+
 # include <sys/syscall.h>
 # include <sys/user.h>
 # include <unistd.h>
@@ -18,6 +20,7 @@
 typedef struct {
 	const char **cmd;
 	const char *tmpdir;
+	char *cmdpath;
 	char *tmppath;
 } t_param;