cscope was used to search new and old FreeBSD source code for the strings "MPTCP" and "mptcp". Results for FreeBSD HEAD and FreeBSD 8.4 are shown below. Except for the added tcpdump files, the prevalence of these strings has scarcely changed.
References to MPTCP/mptcp in the SCTP source code predates FreeBSD 8.4. Examining the file copyright headers, one can speculate that it originated with the work done by Cisco Systems. It is unclear (at least to me) if the strings have alternate meanings in the SCTP context.
FreeBSD HEAD software, pulled from git 02/18/23:
Text string: MPTCP
File Line
0 print-mptcp.c 35 /* \summary: Multipath TCP (MPTCP) printer */
1 print-mptcp.c 51 #define MPTCP_SUB_CAPABLE 0x0
2 print-mptcp.c 52 #define MPTCP_SUB_JOIN 0x1
3 print-mptcp.c 53 #define MPTCP_SUB_DSS 0x2
4 print-mptcp.c 54 #define MPTCP_SUB_ADD_ADDR 0x3
5 print-mptcp.c 55 #define MPTCP_SUB_REMOVE_ADDR 0x4
6 print-mptcp.c 56 #define MPTCP_SUB_PRIO 0x5
7 print-mptcp.c 57 #define MPTCP_SUB_FAIL 0x6
8 print-mptcp.c 58 #define MPTCP_SUB_FCLOSE 0x7
9 print-mptcp.c 66 #define MPTCP_OPT_SUBTYPE(sub_etc) (((sub_etc) >>
4) & 0xF)
a print-mptcp.c 442 subtype = min(MPTCP_OPT_SUBTYPE(opt->sub_etc),
MPTCP_SUB_FCLOSE + 1);
b print-tcp.c 133 { TCPOPT_MPTCP, "mptcp" },
c print-tcp.c 592 case TCPOPT_MPTCP:
d tcp.h 88 #define TCPOPT_MPTCP 30 /* MPTCP options */
e sctp.h 302 #define SCTP_CMT_MPTCP 4
f sctp.h 303 #define SCTP_CMT_MAX SCTP_CMT_MPTCP
g sctp_cc_functions.c 53 #define SHIFT_MPTCP_MULTI_N 40
h sctp_cc_functions.c 54 #define SHIFT_MPTCP_MULTI_Z 16
i sctp_cc_functions.c 55 #define SHIFT_MPTCP_MULTI 8
j sctp_cc_functions.c 708 (stcb->asoc.sctp_cmt_on_off == SCTP_CMT_MPTCP)) {
k sctp_cc_functions.c 718 t_path_mptcp += (((uint64_t)net->cwnd) <<
SHIFT_MPTCP_MULTI_Z) /
l sctp_cc_functions.c 720 tmp = (((uint64_t)net->cwnd) << SHIFT_MPTCP_MULTI_N) /
m sctp_cc_functions.c 882 case SCTP_CMT_MPTCP:
n sctp_cc_functions.c 886 SHIFT_MPTCP_MULTI);
o sctp_cc_functions.c 889 SHIFT_MPTCP_MULTI);
p sctp_cc_functions.c 962 case SCTP_CMT_MPTCP:
q sctp_cc_functions.c 965 SHIFT_MPTCP_MULTI);
r sctp.h 304 #define SCTP_CMT_MPTCP 4
s sctp.h 305 #define SCTP_CMT_MAX SCTP_CMT_MPTCP
---
Text string: mptcp
File Line
0 netdissect.h 551 extern int mptcp_print(netdissect_options *, const
u_char *, u_int, u_char);
1 print-mptcp.c 60 struct mptcp_option {
2 print-mptcp.c 419 } mptcp_options[] = {
3 print-mptcp.c 432 mptcp_print(netdissect_options *ndo,
4 print-mptcp.c 435 const struct mptcp_option *opt;
5 print-mptcp.c 441 opt = (const struct mptcp_option *) cp;
6 print-mptcp.c 444 ND_PRINT((ndo, " %s", mptcp_options[subtype].name));
7 print-mptcp.c 445 return mptcp_options[subtype].print(ndo, cp, len,
flags);
8 print-tcp.c 133 { TCPOPT_MPTCP, "mptcp" },
9 print-tcp.c 595 if (!mptcp_print(ndo, cp-2, len, flags))
a sctp_cc_functions.c 696 uint64_t t_path_mptcp;
b sctp_cc_functions.c 697 uint64_t mptcp_like_alpha;
c sctp_cc_functions.c 704 t_path_mptcp = 0;
d sctp_cc_functions.c 705 mptcp_like_alpha = 1;
e sctp_cc_functions.c 718 t_path_mptcp += (((uint64_t)net->cwnd) <<
SHIFT_MPTCP_MULTI_Z) /
f sctp_cc_functions.c 727 if (t_path_mptcp > 0) {
g sctp_cc_functions.c 728 mptcp_like_alpha = max_path / (t_path_mptcp *
t_path_mptcp);
h sctp_cc_functions.c 730 mptcp_like_alpha = 1;
i sctp_cc_functions.c 884 mptcp_like_alpha *
j sctp_cc_functions.c 888 mptcp_like_alpha) >>
k sctp_cc_functions.c 963 incr = (uint32_t)((mptcp_like_alpha *
FreeBSD 8.4 release software:
Text string: MPTCP
File Line
0 sctp.h 291 #define SCTP_CMT_MPTCP 4
1 sctp.h 292 #define SCTP_CMT_MAX SCTP_CMT_MPTCP
2 sctp_cc_functions.c 51 #define SHIFT_MPTCP_MULTI_N 40
3 sctp_cc_functions.c 52 #define SHIFT_MPTCP_MULTI_Z 16
4 sctp_cc_functions.c 53 #define SHIFT_MPTCP_MULTI 8
5 sctp_cc_functions.c 683 (stcb->asoc.sctp_cmt_on_off == SCTP_CMT_MPTCP)) {
6 sctp_cc_functions.c 694 t_path_mptcp += (((uint64_t) net->cwnd) <<
SHIFT_MPTCP_MULTI_Z) /
7 sctp_cc_functions.c 696 tmp = (((uint64_t) net->cwnd) << SHIFT_MPTCP_MULTI_N)
/
8 sctp_cc_functions.c 859 case SCTP_CMT_MPTCP:
9 sctp_cc_functions.c 863 SHIFT_MPTCP_MULTI);
a sctp_cc_functions.c 866 SHIFT_MPTCP_MULTI);
b sctp_cc_functions.c 938 case SCTP_CMT_MPTCP:
c sctp_cc_functions.c 941 SHIFT_MPTCP_MULTI);
d sctp.h 291 #define SCTP_CMT_MPTCP 4
e sctp.h 292 #define SCTP_CMT_MAX SCTP_CMT_MPTCP
---
Text string: mptcp
File Line
0 sctp_cc_functions.c 670 uint64_t t_path_mptcp;
1 sctp_cc_functions.c 671 uint64_t mptcp_like_alpha;
2 sctp_cc_functions.c 679 t_path_mptcp = 0;
3 sctp_cc_functions.c 680 mptcp_like_alpha = 1;
4 sctp_cc_functions.c 694 t_path_mptcp += (((uint64_t) net->cwnd) <<
SHIFT_MPTCP_MULTI_Z) /
5 sctp_cc_functions.c 703 if (t_path_mptcp > 0) {
6 sctp_cc_functions.c 704 mptcp_like_alpha = max_path / (t_path_mptcp *
t_path_mptcp);
7 sctp_cc_functions.c 706 mptcp_like_alpha = 1;
8 sctp_cc_functions.c 861 mptcp_like_alpha *
9 sctp_cc_functions.c 865 mptcp_like_alpha) >>
a sctp_cc_functions.c 939 incr = (uint32_t) ((mptcp_like_alpha *
MPTCP is not supported by FreeBSD. Earlier work on MPTCP from the Swinburne CAIA project is no longer supported, and can no longer be patched into recent FreeBSD source code without extensive work.