From 26113360b7635f5dc300fe1f3809421465710c14 Mon Sep 17 00:00:00 2001 From: Davide Caratti Date: Thu, 16 Dec 2021 15:29:59 +0100 Subject: [PATCH] mptcp: add support for changing the backup flag Linux supports 'MPTCP_PM_CMD_SET_FLAGS' since v5.12, and this control has recently been extended to allow setting flags for a given endpoint id. Although there is no use for changing 'signal' or 'subflow' flags, it can be helpful to set/clear the backup bit on existing endpoints: add the 'ip mptcp endpoint change <...>' command for this purpose. Link: https://github.com/multipath-tcp/mptcp_net-next/issues/158 Acked-by: Matthieu Baerts Signed-off-by: Davide Caratti Signed-off-by: David Ahern --- ip/ipmptcp.c | 20 ++++++++++++++++---- man/man8/ip-mptcp.8 | 14 ++++++++++++++ 2 files changed, 30 insertions(+), 4 deletions(-) diff --git a/ip/ipmptcp.c b/ip/ipmptcp.c index 433fa68d2..10dcb1ea1 100644 --- a/ip/ipmptcp.c +++ b/ip/ipmptcp.c @@ -25,6 +25,7 @@ static void usage(void) "Usage: ip mptcp endpoint add ADDRESS [ dev NAME ] [ id ID ]\n" " [ port NR ] [ FLAG-LIST ]\n" " ip mptcp endpoint delete id ID\n" + " ip mptcp endpoint change id ID [ backup | nobackup ]\n" " ip mptcp endpoint show [ id ID ]\n" " ip mptcp endpoint flush\n" " ip mptcp limits set [ subflows NR ] [ add_addr_accepted NR ]\n" @@ -45,6 +46,8 @@ static int genl_family = -1; GENL_REQUEST(_req, MPTCP_BUFLEN, genl_family, 0, \ MPTCP_PM_VER, _cmd, _flags) +#define MPTCP_PM_ADDR_FLAG_NOBACKUP 0x0 + /* Mapping from argument to address flag mask */ static const struct { const char *name; @@ -54,6 +57,7 @@ static const struct { { "subflow", MPTCP_PM_ADDR_FLAG_SUBFLOW }, { "backup", MPTCP_PM_ADDR_FLAG_BACKUP }, { "fullmesh", MPTCP_PM_ADDR_FLAG_FULLMESH }, + { "nobackup", MPTCP_PM_ADDR_FLAG_NOBACKUP } }; static void print_mptcp_addr_flags(unsigned int flags) @@ -96,9 +100,9 @@ static int get_flags(const char *arg, __u32 *flags) return -1; } -static int mptcp_parse_opt(int argc, char **argv, struct nlmsghdr *n, - bool adding) +static int mptcp_parse_opt(int argc, char **argv, struct nlmsghdr *n, int cmd) { + bool adding = cmd == MPTCP_PM_CMD_ADD_ADDR; struct rtattr *attr_addr; bool addr_set = false; inet_prefix address; @@ -111,6 +115,11 @@ static int mptcp_parse_opt(int argc, char **argv, struct nlmsghdr *n, ll_init_map(&rth); while (argc > 0) { if (get_flags(*argv, &flags) == 0) { + /* allow changing the 'backup' flag only */ + if (cmd == MPTCP_PM_CMD_SET_FLAGS && + (flags & ~MPTCP_PM_ADDR_FLAG_BACKUP)) + invarg("invalid flags\n", *argv); + } else if (matches(*argv, "id") == 0) { NEXT_ARG(); @@ -183,7 +192,7 @@ static int mptcp_addr_modify(int argc, char **argv, int cmd) MPTCP_REQUEST(req, cmd, NLM_F_REQUEST); int ret; - ret = mptcp_parse_opt(argc, argv, &req.n, cmd == MPTCP_PM_CMD_ADD_ADDR); + ret = mptcp_parse_opt(argc, argv, &req.n, cmd); if (ret) return ret; @@ -299,7 +308,7 @@ static int mptcp_addr_show(int argc, char **argv) if (argc <= 0) return mptcp_addr_dump(); - ret = mptcp_parse_opt(argc, argv, &req.n, false); + ret = mptcp_parse_opt(argc, argv, &req.n, MPTCP_PM_CMD_GET_ADDR); if (ret) return ret; @@ -531,6 +540,9 @@ int do_mptcp(int argc, char **argv) if (matches(*argv, "add") == 0) return mptcp_addr_modify(argc-1, argv+1, MPTCP_PM_CMD_ADD_ADDR); + if (matches(*argv, "change") == 0) + return mptcp_addr_modify(argc-1, argv+1, + MPTCP_PM_CMD_SET_FLAGS); if (matches(*argv, "delete") == 0) return mptcp_addr_modify(argc-1, argv+1, MPTCP_PM_CMD_DEL_ADDR); diff --git a/man/man8/ip-mptcp.8 b/man/man8/ip-mptcp.8 index 019debe2f..0e6e15321 100644 --- a/man/man8/ip-mptcp.8 +++ b/man/man8/ip-mptcp.8 @@ -34,6 +34,13 @@ ip-mptcp \- MPTCP path manager configuration .BR "ip mptcp endpoint del id " .I ID +.ti -8 +.BR "ip mptcp endpoint change id " +.I ID +.RB "[ " +.I BACKUP-OPT +.RB "] " + .ti -8 .BR "ip mptcp endpoint show " .RB "[ " id @@ -57,6 +64,13 @@ ip-mptcp \- MPTCP path manager configuration .B fullmesh .RB "]" +.ti -8 +.IR BACKUP-OPT " := [" +.B backup +.RB "|" +.B nobackup +.RB "]" + .ti -8 .BR "ip mptcp limits set " .RB "[ " -- 2.47.3