remove redundancy in HDLC encapsulation

Tested with F5 HDLC and non-HDLC

Signed-off-by: Daniel Lenski <dlenski@gmail.com>

diff --git a/ppp.c b/ppp.c
index 1bea0d46488612ac2fd58fca76e393f6281ccc45..1f23b54e52c2ac515040c6b0c6a490a440323a27 100644 (file)
--- a/ppp.c
+++ b/ppp.c
@@ -67,9 +67,10 @@ static const uint16_t fcstab[256] = {
                *outp++ = (c);        \
 } while (0)
 
-static struct pkt *hdlc_into_new_pkt(struct openconnect_info *vpninfo, unsigned char *bytes, int len, int asyncmap)
+static struct pkt *hdlc_into_new_pkt(struct openconnect_info *vpninfo, struct pkt *old, int asyncmap)
 {
-        const unsigned char *inp = bytes, *endp = bytes + len;
+       int len = old->len + old->ppp.hlen;
+       const unsigned char *inp = old->data - old->ppp.hlen, *endp = inp + len;
        unsigned char *outp;
        uint16_t fcs = PPPINITFCS16;
        /* Every byte in payload and 2-byte FCS potentially expands to two bytes,
@@ -987,33 +988,26 @@ int ppp_mainloop(struct openconnect_info *vpninfo, int *timeout, int readable)
                /* Add PPP header and reserve space for pre-PPP encapsulation header */
                unsigned char *eh = add_ppp_header(this, ppp, proto);
 
-               /* Add pre-PPP encapsulation header */
-               switch (ppp->encap) {
-               case PPP_ENCAP_F5:
-                       store_be16(eh, 0xf500);
-                       store_be16(eh + 2, this->len + this->ppp.hlen - 4);
-                       break;
-               case PPP_ENCAP_F5_HDLC:
-               case PPP_ENCAP_FORTINET_HDLC:
+               /* XX: Copy the whole packet into new HDLC'ed packet if needed */
+               if (ppp->hdlc) {
                        /* XX: use worst-case escaping for LCP */
-                       this = hdlc_into_new_pkt(vpninfo, this->data - this->ppp.hlen, this->len + this->ppp.hlen,
+                       this = hdlc_into_new_pkt(vpninfo, this,
                                                 proto == PPP_LCP ? ASYNCMAP_LCP : ppp->out_asyncmap);
                        if (!this)
                                return 1; /* XX */
                        free(vpninfo->current_ssl_pkt);
                        vpninfo->current_ssl_pkt = this;
+               }
+
+               /* Add pre-PPP encapsulation header */
+               switch (ppp->encap) {
+               case PPP_ENCAP_F5:
+                       store_be16(eh, 0xf500);
+                       store_be16(eh + 2, this->len + this->ppp.hlen - 4);
                        break;
                case PPP_ENCAP_NX_HDLC:
-                       /* XX: use worst-case escaping for LCP */
-                       this = hdlc_into_new_pkt(vpninfo, this->data - this->ppp.hlen, this->len + this->ppp.hlen,
-                                                proto == PPP_LCP ? ASYNCMAP_LCP : ppp->out_asyncmap);
-                       if (!this)
-                               return 1; /* XX */
-
                        /* XX: header is simply the number of bytes on the wire (excluding itself) */
                        store_be32(eh, this->len + this->ppp.hlen - 4);
-                       free(vpninfo->current_ssl_pkt);
-                       vpninfo->current_ssl_pkt = this;
                        break;
                }