X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/11996ba4147678c1d400dcc16e33d83a9a3ede9c..b85ea8667082555c4ae3a94650921584cfbcb3bb:/ppp.c?ds=sidebyside diff --git a/ppp.c b/ppp.c index 5ed8563..e8c3b52 100644 --- a/ppp.c +++ b/ppp.c @@ -2607,6 +2607,85 @@ uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, sessionidt s, tunnelid return b; } +// fill in a L2TP message with a PPP frame, +// returns start of PPP frame +//(note: THIS ROUTINE CAN WRITES TO p[-28]). +uint8_t *opt_makeppp(uint8_t *p, int l, sessionidt s, tunnelidt t, uint16_t mtype, uint8_t prio, bundleidt bid, uint8_t mp_bits) +{ + uint16_t hdr = 0x0002; // L2TP with no options + uint16_t type = mtype; + uint8_t *b = p; + + if (t == TUNNEL_ID_PPPOE) + { + return opt_pppoe_makeppp(p, l, s, t, mtype, prio, bid, mp_bits); + } + + // Check whether this session is part of multilink + if (bid) + { + if (bundle[bid].num_of_links > 1) + type = PPPMP; // Change PPP message type to the PPPMP + else + bid = 0; + } + + if (bid) + { + // Add the message type if this fragment has the begin bit set + if (mp_bits & MP_BEGIN) + { + b -= 2; + *(uint16_t *) b = htons(mtype); // Message type + } + + // Set the sequence number and (B)egin (E)nd flags + if (session[s].mssf) + { + // Set the multilink bits + uint16_t bits_send = mp_bits; + b -= 2; + *(uint16_t *) b = htons((bundle[bid].seq_num_t & 0x0FFF)|bits_send); + } + else + { + b -= 4; + *(uint32_t *) b = htonl(bundle[bid].seq_num_t); + // Set the multilink bits + *b = mp_bits; + } + + bundle[bid].seq_num_t++; + } + + if (type < 0x100 && session[s].flags & SESSION_PFC) + { + b--; + *b = type; + } + else + { + b -= 2; + *(uint16_t *) b = htons(type); + } + + if (type == PPPLCP || !(session[s].flags & SESSION_ACFC)) + { + b -= 2; + *(uint16_t *) b = htons(0xFF03); // HDLC header + } + + if (prio) hdr |= 0x0100; // set priority bit + b -= 2; + *(uint16_t *) b = htons(session[s].far); // session + b -= 2; + *(uint16_t *) b = htons(tunnel[t].far); // tunnel + b -= 2; + *(uint16_t *) b = htons(hdr); + + return b; +} + static int add_lcp_auth(uint8_t *b, int size, int authtype) { int len = 0;