break out fs_tracefile function

1 files changed, 39 insertions, 37 deletions

diff --git a/src/firejail/fs_trace.c b/src/firejail/fs_trace.c
index 9ade0bdc3..c1b821cce 100644
--- a/src/firejail/fs_trace.c
+++ b/src/firejail/fs_trace.c
@@ -41,44 +41,46 @@ void fs_trace_preload(void) {
                 fclose(fp);
                 fs_logger("touch /etc/ld.so.preload");
         }
-        if (arg_tracefile) {
-                if (arg_debug)
-                        printf("Creating an empty trace log file: %s\n", arg_tracefile);
-                // create a bind mounted trace logfile that the sandbox can see
-                EUID_USER();
-                int fd = open(arg_tracefile, O_CREAT|O_RDWR, S_IRUSR | S_IWRITE | S_IRGRP | S_IROTH);
-                if (fd == -1) {
-                        perror("open");
-                        fprintf(stderr, "Error: cannot open trace log file %s\n", arg_tracefile);
-                        exit(1);
-                }
-                if (fstat(fd, &s) == -1)
-                        errExit("fstat");
-                if (!S_ISREG(s.st_mode)) {
-                        fprintf(stderr, "Error: cannot write trace log: %s is no regular file\n", arg_tracefile);
-                        exit(1);
-                }
-                if (ftruncate(fd, 0) == -1)
-                        errExit("ftruncate");
-                EUID_ROOT();
-                FILE *fp = fopen(RUN_TRACE_FILE, "w");
-                if (!fp)
-                        errExit("fopen " RUN_TRACE_FILE);
-                fclose(fp);
-                fs_logger2("touch ", arg_tracefile);
-                // mount using the symbolic link in /proc/self/fd
-                if (arg_debug)
-                        printf("Bind mount %s to %s\n", arg_tracefile, RUN_TRACE_FILE);
-                char *proc;
-                if (asprintf(&proc, "/proc/self/fd/%d", fd) == -1)
-                        errExit("asprintf");
-                if (mount(proc, RUN_TRACE_FILE, NULL, MS_BIND|MS_REC, NULL) < 0)
-                        errExit("mount bind " RUN_TRACE_FILE);
-                free(proc);
-                close(fd);
-                // now that RUN_TRACE_FILE is user-writable, mount it noexec
-                fs_remount(RUN_TRACE_FILE, MOUNT_NOEXEC, 0);
+}
+
+void fs_tracefile(void) {
+        // create a bind mounted trace logfile that the sandbox can see
+        if (arg_debug)
+                printf("Creating an empty trace log file: %s\n", arg_tracefile);
+        EUID_USER();
+        int fd = open(arg_tracefile, O_CREAT|O_WRONLY|O_CLOEXEC, S_IRUSR | S_IWRITE | S_IRGRP | S_IROTH);
+        if (fd == -1) {
+                perror("open");
+                fprintf(stderr, "Error: cannot open trace log file %s for writing\n", arg_tracefile);
+                exit(1);
+        }
+        struct stat s;
+        if (fstat(fd, &s) == -1)
+                errExit("fstat");
+        if (!S_ISREG(s.st_mode)) {
+                fprintf(stderr, "Error: cannot write trace log: %s is no regular file\n", arg_tracefile);
+                exit(1);
         }
+        if (ftruncate(fd, 0) == -1)
+                errExit("ftruncate");
+        EUID_ROOT();
+        FILE *fp = fopen(RUN_TRACE_FILE, "w");
+        if (!fp)
+                errExit("fopen " RUN_TRACE_FILE);
+        fclose(fp);
+        fs_logger2("touch ", arg_tracefile);
+        // mount using the symbolic link in /proc/self/fd
+        if (arg_debug)
+                printf("Bind mount %s to %s\n", arg_tracefile, RUN_TRACE_FILE);
+        char *proc;
+        if (asprintf(&proc, "/proc/self/fd/%d", fd) == -1)
+                errExit("asprintf");
+        if (mount(proc, RUN_TRACE_FILE, NULL, MS_BIND|MS_REC, NULL) < 0)
+                errExit("mount bind " RUN_TRACE_FILE);
+        free(proc);
+        close(fd);
+        // now that RUN_TRACE_FILE is user-writable, mount it noexec
+        fs_remount(RUN_TRACE_FILE, MOUNT_NOEXEC, 0);
 }
 
 void fs_trace(void) {