reimplement --get using --cat

1 files changed, 36 insertions, 86 deletions

diff --git a/src/firejail/ls.c b/src/firejail/ls.c
index 4d0a001b6..ebd65cdd3 100644
--- a/src/firejail/ls.c
+++ b/src/firejail/ls.c
@@ -26,6 +26,7 @@
 #include <dirent.h>
 #include <pwd.h>
 #include <grp.h>
+#include <fcntl.h>
 //#include <dirent.h>
 //#include <stdio.h>
 //#include <stdlib.h>
@@ -291,6 +292,41 @@ void sandboxfs(int op, pid_t pid, const char *path1, const char *path2) {
                 printf("file2 %s\n", fname2 ? fname2 : "(null)");
         }
 
+        // get file from sandbox and store it in the current directory
+        // implemented using --cat
+        if (op == SANDBOX_FS_GET) {
+                char *dest_fname = strrchr(fname1, '/');
+                if (!dest_fname || *(++dest_fname) == '\0') {
+                        fprintf(stderr, "Error: invalid file name %s\n", fname1);
+                        exit(1);
+                }
+                // create destination file if necessary
+                EUID_ASSERT();
+                int fd = open(dest_fname, O_WRONLY|O_CREAT|O_CLOEXEC, S_IRUSR | S_IWRITE);
+                if (fd == -1) {
+                        fprintf(stderr, "Error: cannot open %s for writing\n", dest_fname);
+                        exit(1);
+                }
+                struct stat s;
+                if (fstat(fd, &s) == -1)
+                        errExit("fstat");
+                if (!S_ISREG(s.st_mode)) {
+                        fprintf(stderr, "Error: %s is no regular file\n", dest_fname);
+                        exit(1);
+                }
+                if (ftruncate(fd, 0) == -1)
+                        errExit("ftruncate");
+                // go quiet - messages on stdout will corrupt the file
+                arg_debug = 0;
+                arg_quiet = 1;
+                // redirection
+                if (dup2(fd, STDOUT_FILENO) == -1)
+                        errExit("dup2");
+                assert(fd != STDOUT_FILENO);
+                close(fd);
+                op = SANDBOX_FS_CAT;
+        }
+
         // sandbox root directory
         char *rootdir;
         if (asprintf(&rootdir, "/proc/%d/root", pid) == -1)
@@ -327,92 +363,6 @@ void sandboxfs(int op, pid_t pid, const char *path1, const char *path2) {
                 else
                         exit(1);
         }
-
-        // get file from sandbox and store it in the current directory
-        else if (op == SANDBOX_FS_GET) {
-                char *src_fname =fname1;
-                char *dest_fname = strrchr(fname1, '/');
-                if (!dest_fname || *(++dest_fname) == '\0') {
-                        fprintf(stderr, "Error: invalid file name %s\n", fname1);
-                        exit(1);
-                }
-
-                EUID_ROOT();
-                if (arg_debug)
-                        printf("copy %s to %s\n", src_fname, dest_fname);
-
-                // create a user-owned temporary file in /run/firejail directory
-                char tmp_fname[] = "/run/firejail/tmpget-XXXXXX";
-                int fd = mkstemp(tmp_fname);
-                if (fd == -1) {
-                        fprintf(stderr, "Error: cannot create temporary file %s\n", tmp_fname);
-                        exit(1);
-                }
-                SET_PERMS_FD(fd, getuid(), getgid(), 0600);
-                close(fd);
-
-                // copy the source file into the temporary file - we need to chroot
-                pid_t child = fork();
-                if (child < 0)
-                        errExit("fork");
-                if (child == 0) {
-                        // chroot
-                        if (chroot(rootdir) < 0)
-                                errExit("chroot");
-                        if (chdir("/") < 0)
-                                errExit("chdir");
-
-                        // drop privileges
-                        drop_privs(0);
-
-                        // copy the file
-                        if (copy_file(src_fname, tmp_fname, getuid(), getgid(), 0600)) // already a regular user
-                                _exit(1);
-#ifdef HAVE_GCOV
-                        __gcov_flush();
-#endif
-                        _exit(0);
-                }
-
-                // wait for the child to finish
-                int status = 0;
-                waitpid(child, &status, 0);
-                if (WIFEXITED(status) && WEXITSTATUS(status) == 0);
-                else {
-                        unlink(tmp_fname);
-                        exit(1);
-                }
-
-                // copy the temporary file into the destination file
-                child = fork();
-                if (child < 0)
-                        errExit("fork");
-                if (child == 0) {
-                        // drop privileges
-                        drop_privs(0);
-
-                        // copy the file
-                        if (copy_file(tmp_fname, dest_fname, getuid(), getgid(), 0600)) // already a regular user
-                                _exit(1);
-#ifdef HAVE_GCOV
-                        __gcov_flush();
-#endif
-                        _exit(0);
-                }
-
-                // wait for the child to finish
-                status = 0;
-                waitpid(child, &status, 0);
-                if (WIFEXITED(status) && WEXITSTATUS(status) == 0);
-                else {
-                        unlink(tmp_fname);
-                        exit(1);
-                }
-
-                // remove the temporary file
-                unlink(tmp_fname);
-                EUID_USER();
-        }
         // get file from host and store it in the sandbox
         else if (op == SANDBOX_FS_PUT && path2) {
                 char *src_fname =fname1;