Guard against handling many SIGTERM/SIGINT.

Privsep has a mini-eloop for reading data from other processes.
This mini-eloop processes signals as well so we can reap children.
During teardown we don't want to process SIGTERM or SIGINT again,
as that could trigger memory issues.

Hopefully fixes #247.

diff --git a/src/dhcpcd.c b/src/dhcpcd.c
index 0cc62226a23db6dc36a6d237743eff7a9856c5bd..5de55fafc63d500e15643b03b100828f8f03b558 100644 (file)
--- a/src/dhcpcd.c
+++ b/src/dhcpcd.c
@@ -1414,6 +1414,7 @@ dhcpcd_renew(struct dhcpcd_ctx *ctx)
 
 #ifdef USE_SIGNALS
 #define sigmsg "received %s, %s"
+static volatile bool dhcpcd_exiting = false;
 void
 dhcpcd_signal_cb(int sig, void *arg)
 {
@@ -1486,9 +1487,20 @@ dhcpcd_signal_cb(int sig, void *arg)
                return;
        }
 
+       /*
+        * Privsep has a mini-eloop for reading data from other processes.
+        * This mini-eloop processes signals as well so we can reap children.
+        * During teardown we don't want to process SIGTERM or SIGINT again,
+        * as that could trigger memory issues.
+        */
+       if (dhcpcd_exiting)
+               return;
+
+       dhcpcd_exiting = true;
        if (!(ctx->options & DHCPCD_TEST))
                stop_all_interfaces(ctx, opts);
        eloop_exit(ctx->eloop, exit_code);
+       dhcpcd_exiting = false;
 }
 #endif