From: Prasad J Pandit <p...@fedoraproject.org> Refactor 'net_bridge_run_helper' routine to avoid buffer formatting to prepare 'helper_cmd' and using shell to invoke helper command. Instead directly execute helper program with due arguments.
Signed-off-by: Prasad J Pandit <p...@fedoraproject.org> --- net/tap.c | 43 +++++++++---------------------------------- 1 file changed, 9 insertions(+), 34 deletions(-) Update v3: remove buffer formatting and use of shell to invoke helper -> https://lists.gnu.org/archive/html/qemu-devel/2019-07/msg00071.html diff --git a/net/tap.c b/net/tap.c index e8aadd8d4b..bc9b3407a6 100644 --- a/net/tap.c +++ b/net/tap.c @@ -478,7 +478,6 @@ static int net_bridge_run_helper(const char *helper, const char *bridge, sigset_t oldmask, mask; int pid, status; char *args[5]; - char **parg; int sv[2]; sigemptyset(&mask); @@ -498,9 +497,6 @@ static int net_bridge_run_helper(const char *helper, const char *bridge, } if (pid == 0) { int open_max = sysconf(_SC_OPEN_MAX), i; - char fd_buf[6+10]; - char br_buf[6+IFNAMSIZ] = {0}; - char helper_cmd[PATH_MAX + sizeof(fd_buf) + sizeof(br_buf) + 15]; for (i = 3; i < open_max; i++) { if (i != sv[1]) { @@ -508,39 +504,18 @@ static int net_bridge_run_helper(const char *helper, const char *bridge, } } - snprintf(fd_buf, sizeof(fd_buf), "%s%d", "--fd=", sv[1]); + args[0] = (char *)helper; + args[1] = (char *)"--use-vnet"; + args[2] = g_strdup_printf("%s%d", "--fd=", sv[1]); + args[3] = g_strdup_printf("%s%s", "--br=", bridge); + args[4] = NULL; - if (strrchr(helper, ' ') || strrchr(helper, '\t')) { - /* assume helper is a command */ + execv(helper, args); - if (strstr(helper, "--br=") == NULL) { - snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge); - } + g_free(args[2]); + g_free(args[3]); + fprintf(stderr, "failed to execute helper: %s\n", helper); - snprintf(helper_cmd, sizeof(helper_cmd), "%s %s %s %s", - helper, "--use-vnet", fd_buf, br_buf); - - parg = args; - *parg++ = (char *)"sh"; - *parg++ = (char *)"-c"; - *parg++ = helper_cmd; - *parg++ = NULL; - - execv("/bin/sh", args); - } else { - /* assume helper is just the executable path name */ - - snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge); - - parg = args; - *parg++ = (char *)helper; - *parg++ = (char *)"--use-vnet"; - *parg++ = fd_buf; - *parg++ = br_buf; - *parg++ = NULL; - - execv(helper, args); - } _exit(1); } else { -- 2.21.0
