No need for a loop around the recv() now that we don't have to worry

about EINTR.  CID 180697

diff --git a/src/exec_pty.c b/src/exec_pty.c
index 275a28e1d1a818d158b4a429618d27a24e342e26..c813924a5a2affa6264afd3a6a527b78e4a47a9b 100644 (file)
--- a/src/exec_pty.c
+++ b/src/exec_pty.c
@@ -828,87 +828,85 @@ backchannel_cb(int fd, int what, void *v)
      * Read command status from the monitor.
      * Note that the backchannel is a *blocking* socket.
      */
-    for (;;) {
-       nread = recv(fd, &cstat, sizeof(cstat), MSG_WAITALL);
-       switch (nread) {
-       case -1:
-           switch (errno) {
-           case EINTR:
-           case EAGAIN:
-               /* Nothing ready. */
-               break;
-           default:
-               if (ec->cstat->val == CMD_INVALID) {
-                   ec->cstat->type = CMD_ERRNO;
-                   ec->cstat->val = errno;
-                   sudo_debug_printf(SUDO_DEBUG_ERROR,
-                       "%s: failed to read command status: %s",
-                       __func__, strerror(errno));
-                   sudo_ev_loopbreak(ec->evbase);
-               }
-               break;
-           }
-           break;
-       case 0:
-           /* EOF, monitor exited or was killed. */
-           sudo_debug_printf(SUDO_DEBUG_INFO,
-               "EOF on backchannel, monitor dead?");
-           if (ec->cstat->type == CMD_INVALID) {
-               /* XXX - need new CMD_ type for monitor errors. */
-               ec->cstat->type = CMD_ERRNO;
-               ec->cstat->val = ECONNRESET;
-           }
-           sudo_ev_loopexit(ec->evbase);
-           break;
-       case sizeof(cstat):
-           /* Check command status. */
-           switch (cstat.type) {
-           case CMD_PID:
-               ec->cmnd_pid = cstat.val;
-               sudo_debug_printf(SUDO_DEBUG_INFO, "executed %s, pid %d",
-                   ec->details->command, (int)ec->cmnd_pid);
-               break;
-           case CMD_WSTATUS:
-               if (WIFSTOPPED(cstat.val)) {
-                   int signo;
-
-                   /* Suspend parent and tell monitor how to resume on return. */
-                   sudo_debug_printf(SUDO_DEBUG_INFO,
-                       "command stopped, suspending parent");
-                   signo = suspend_sudo(WSTOPSIG(cstat.val), ec->ppgrp);
-                   schedule_signal(ec, signo);
-                   /* Re-enable I/O events */
-                   add_io_events(ec->evbase);
-               } else {
-                   /* Command exited or was killed, either way we are done. */
-                   sudo_debug_printf(SUDO_DEBUG_INFO, "command exited or was killed");
-                   sudo_ev_loopexit(ec->evbase);
-               }
-               *ec->cstat = cstat;
-               break;
-           case CMD_ERRNO:
-               /* Monitor was unable to execute command or broken pipe. */
-               sudo_debug_printf(SUDO_DEBUG_INFO, "errno from monitor: %s",
-                   strerror(cstat.val));
-               sudo_ev_loopbreak(ec->evbase);
-               *ec->cstat = cstat;
-               break;
-           }
-           /* Keep reading command status messages until EAGAIN or EOF. */
+    nread = recv(fd, &cstat, sizeof(cstat), MSG_WAITALL);
+    switch (nread) {
+    case -1:
+       switch (errno) {
+       case EINTR:
+       case EAGAIN:
+           /* Nothing ready. */
            break;
        default:
-           /* Short read, should not happen. */
            if (ec->cstat->val == CMD_INVALID) {
                ec->cstat->type = CMD_ERRNO;
-               ec->cstat->val = EIO;
+               ec->cstat->val = errno;
                sudo_debug_printf(SUDO_DEBUG_ERROR,
-                   "%s: failed to read command status: short read", __func__);
+                   "%s: failed to read command status: %s",
+                   __func__, strerror(errno));
                sudo_ev_loopbreak(ec->evbase);
            }
            break;
        }
-       debug_return;
+       break;
+    case 0:
+       /* EOF, monitor exited or was killed. */
+       sudo_debug_printf(SUDO_DEBUG_INFO,
+           "EOF on backchannel, monitor dead?");
+       if (ec->cstat->type == CMD_INVALID) {
+           /* XXX - need new CMD_ type for monitor errors. */
+           ec->cstat->type = CMD_ERRNO;
+           ec->cstat->val = ECONNRESET;
+       }
+       sudo_ev_loopexit(ec->evbase);
+       break;
+    case sizeof(cstat):
+       /* Check command status. */
+       switch (cstat.type) {
+       case CMD_PID:
+           ec->cmnd_pid = cstat.val;
+           sudo_debug_printf(SUDO_DEBUG_INFO, "executed %s, pid %d",
+               ec->details->command, (int)ec->cmnd_pid);
+           break;
+       case CMD_WSTATUS:
+           if (WIFSTOPPED(cstat.val)) {
+               int signo;
+
+               /* Suspend parent and tell monitor how to resume on return. */
+               sudo_debug_printf(SUDO_DEBUG_INFO,
+                   "command stopped, suspending parent");
+               signo = suspend_sudo(WSTOPSIG(cstat.val), ec->ppgrp);
+               schedule_signal(ec, signo);
+               /* Re-enable I/O events */
+               add_io_events(ec->evbase);
+           } else {
+               /* Command exited or was killed, either way we are done. */
+               sudo_debug_printf(SUDO_DEBUG_INFO, "command exited or was killed");
+               sudo_ev_loopexit(ec->evbase);
+           }
+           *ec->cstat = cstat;
+           break;
+       case CMD_ERRNO:
+           /* Monitor was unable to execute command or broken pipe. */
+           sudo_debug_printf(SUDO_DEBUG_INFO, "errno from monitor: %s",
+               strerror(cstat.val));
+           sudo_ev_loopbreak(ec->evbase);
+           *ec->cstat = cstat;
+           break;
+       }
+       /* Keep reading command status messages until EAGAIN or EOF. */
+       break;
+    default:
+       /* Short read, should not happen. */
+       if (ec->cstat->val == CMD_INVALID) {
+           ec->cstat->type = CMD_ERRNO;
+           ec->cstat->val = EIO;
+           sudo_debug_printf(SUDO_DEBUG_ERROR,
+               "%s: failed to read command status: short read", __func__);
+           sudo_ev_loopbreak(ec->evbase);
+       }
+       break;
     }
+    debug_return;
 }
 
 /*