1 files changed, 40 insertions, 0 deletions
diff --git a/tests/unit/lcp_safeguards_test.c b/tests/unit/lcp_safeguards_test.c
new file mode 100644
index 00000000..32a14dfb
--- /dev/null
+++ b/tests/unit/lcp_safeguards_test.c
@@ -0,0 +1,40 @@
+/* Exercise production Echo-Reply handling at the negotiated MTU. */
+#include <assert.h>
+#include "triton.h"
+#undef DEFINE_INIT
+#define DEFINE_INIT(o, f)
+#include "../../accel-pppd/ppp/ppp_lcp.c"
+
+int conf_ppp_verbose;
+static int sent, sent_len;
+void log_ppp_debug(const char *fmt, ...) {}
+int ppp_chan_send(struct ppp_t *ppp, void *buf, int size)
+{
+	const struct lcp_hdr_t *hdr = buf;
+	assert(size == ntohs(hdr->len) + 2);
+	assert(hdr->code == ECHOREP);
+	sent++;
+	sent_len = size;
+	return 0;
+}
+int main(void)
+{
+	unsigned char buf[1502] = {0};
+	struct ppp_t ppp = {.buf = buf, .buf_size = sizeof(buf), .mtu = 1492};
+	struct ppp_lcp_t lcp = {.ppp = &ppp, .magic = 0x12345678};
+	struct lcp_hdr_t *hdr = (void *)buf;
+
+	hdr->len = htons(1493);
+	hdr->code = ECHOREQ;
+	send_echo_reply(&lcp);
+	assert(!sent && hdr->code == ECHOREQ);
+	hdr->len = htons(1492);
+	send_echo_reply(&lcp);
+	assert(sent == 1 && sent_len == 1494);
+	assert(u_read_be32(hdr + 1) == lcp.magic);
+	hdr->len = htons(8);
+	send_echo_reply(&lcp);
+	assert(sent == 2 && sent_len == 10);
+	puts("LCP safeguards: PASS");
+	return 0;
+}