diff options
Diffstat (limited to 'net/tap.c')
| -rw-r--r-- | net/tap.c | 34 |
1 files changed, 20 insertions, 14 deletions
diff --git a/net/tap.c b/net/tap.c index 51f7aec39d..3f90022c0b 100644 --- a/net/tap.c +++ b/net/tap.c @@ -385,6 +385,24 @@ static TAPState *net_tap_fd_init(NetClientState *peer, return s; } +static void close_all_fds_after_fork(int excluded_fd) +{ + const int skip_fd[] = {STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO, + excluded_fd}; + unsigned int nskip = ARRAY_SIZE(skip_fd); + + /* + * skip_fd must be an ordered array of distinct fds, exclude + * excluded_fd if already included in the [STDIN_FILENO - STDERR_FILENO] + * range + */ + if (excluded_fd <= STDERR_FILENO) { + nskip--; + } + + qemu_close_all_open_fd(skip_fd, nskip); +} + static void launch_script(const char *setup_script, const char *ifname, int fd, Error **errp) { @@ -400,13 +418,7 @@ static void launch_script(const char *setup_script, const char *ifname, return; } if (pid == 0) { - int open_max = sysconf(_SC_OPEN_MAX), i; - - for (i = 3; i < open_max; i++) { - if (i != fd) { - close(i); - } - } + close_all_fds_after_fork(fd); parg = args; *parg++ = (char *)setup_script; *parg++ = (char *)ifname; @@ -490,17 +502,11 @@ static int net_bridge_run_helper(const char *helper, const char *bridge, return -1; } if (pid == 0) { - int open_max = sysconf(_SC_OPEN_MAX), i; char *fd_buf = NULL; char *br_buf = NULL; char *helper_cmd = NULL; - for (i = 3; i < open_max; i++) { - if (i != sv[1]) { - close(i); - } - } - + close_all_fds_after_fork(sv[1]); fd_buf = g_strdup_printf("%s%d", "--fd=", sv[1]); if (strrchr(helper, ' ') || strrchr(helper, '\t')) { |