Repository : ssh://git@diktynna/batctl

On branch : master

commit 07bacdf37dc6d703346886a0b0955c4874dfd0bc Author: Sven Eckelmann sven@narfation.org Date: Sun Oct 11 13:09:50 2020 +0200

batctl: Allow to configure routing_algo during interface creation

A batadv net_device is associated to a B.A.T.M.A.N. routing algorithm. This algorithm has to be selected before the interface is initialized and cannot be changed after that. The only way to select this algorithm was a module parameter which specifies the default algorithm used during the creation of the net_device.

This module parameter is writeable over /sys/module/batman_adv/parameters/routing_algo and thus allows switching of the routing algorithm:

1. change routing_algo parameter 2. create new batadv net_device

But this is not race free because another process can be scheduled between 1 + 2 and in that time frame change the routing_algo parameter again.

It is much cleaner to directly provide this information inside the rtnetlink's RTM_NEWLINK message. The two processes would be (in regards of the creation parameter of their batadv interfaces) be isolated.

This can now be done (with a compatible kernel module) using the routing_algo parameter of interface create:

$ batctl meshif bat0 interface create routing_algo BATMAN_IV or $ batctl meshif bat0 interface create routing_algo BATMAN_V

Signed-off-by: Sven Eckelmann sven@narfation.org

07bacdf37dc6d703346886a0b0955c4874dfd0bc batman_adv.h | 26 +++++++++++++++++++++++ interface.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++----- man/batctl.8 | 8 ++++--- 3 files changed, 95 insertions(+), 8 deletions(-)

diff --git a/batman_adv.h b/batman_adv.h index bb0ae94..bdb317f 100644 --- a/batman_adv.h +++ b/batman_adv.h @@ -675,4 +675,30 @@ enum batadv_tp_meter_reason { BATADV_TP_REASON_TOO_MANY = 133, };

+/** + * enum batadv_ifla_attrs - batman-adv ifla nested attributes + */ +enum batadv_ifla_attrs { + /** + * @IFLA_BATADV_UNSPEC: unspecified attribute which is not parsed by + * rtnetlink + */ + IFLA_BATADV_UNSPEC, + + /** + * @IFLA_BATADV_ALGO_NAME: routing algorithm (name) which should be + * used by the newly registered batadv net_device. + */ + IFLA_BATADV_ALGO_NAME, + + /* add attributes above here, update the policy in soft-interface.c */ + + /** + * @__IFLA_BATADV_MAX: internal use + */ + __IFLA_BATADV_MAX, +}; + +#define IFLA_BATADV_MAX (__IFLA_BATADV_MAX - 1) + #endif /* _UAPI_LINUX_BATMAN_ADV_H_ */ diff --git a/interface.c b/interface.c index d0d9435..73720e3 100644 --- a/interface.c +++ b/interface.c @@ -29,7 +29,8 @@ static void interface_usage(void) { fprintf(stderr, "Usage: batctl [options] interface [parameters] [add|del iface(s)]\n"); - fprintf(stderr, " batctl [options] interface [parameters] [create|destroy]\n"); + fprintf(stderr, " batctl [options] interface [parameters] create [routing_algo|ra RA_NAME]\n"); + fprintf(stderr, " batctl [options] interface [parameters] destroy\n"); fprintf(stderr, "parameters:\n"); fprintf(stderr, " \t -M disable automatic creation of batman-adv interface\n"); fprintf(stderr, " \t -h print this help\n"); @@ -256,12 +257,47 @@ static unsigned int count_interfaces(char *mesh_iface) return count_arg.count; }

-static int create_interface(const char *mesh_iface) +struct interface_create_params { + const char *routing_algo; +}; + +static int +interface_parse_create_params(int argc, char **argv, + struct interface_create_params *create_params) +{ + int pos = 1; + + while (pos < argc) { + if (strcmp(argv[pos], "routing_algo") == 0 || + strcmp(argv[pos], "ra") == 0) { + pos++; + if (pos >= argc) { + fprintf(stderr, + "Error - missing parameter for 'routing_algo'\n"); + return -EINVAL; + } + + create_params->routing_algo = argv[pos]; + pos++; + } else { + fprintf(stderr, + "Error - unknown parameter '%s'\n", + argv[pos]); + return -EINVAL; + } + } + + return 0; +} + +static int create_interface(const char *mesh_iface, + const struct interface_create_params *create_param) { struct ifinfomsg rt_hdr = { .ifi_family = IFLA_UNSPEC, }; struct nlattr *linkinfo; + struct nlattr *linkdata; struct nl_msg *msg; int err = 0; int ret; @@ -296,6 +332,22 @@ static int create_interface(const char *mesh_iface) goto err_free_msg; }

+ linkdata = nla_nest_start(msg, IFLA_INFO_DATA); + if (!linkdata) { + err = -ENOMEM; + goto err_free_msg; + } + + if (create_param->routing_algo) { + ret = nla_put_string(msg, IFLA_BATADV_ALGO_NAME, + create_param->routing_algo); + if (ret < 0) { + err = -ENOMEM; + goto err_free_msg; + } + } + + nla_nest_end(msg, linkdata); nla_nest_end(msg, linkinfo);

err = netlink_simple_request(msg); @@ -382,6 +434,7 @@ err_free_msg:

static int interface(struct state *state, int argc, char **argv) { + struct interface_create_params create_params = {}; int i, optchar; int ret; unsigned int ifindex; @@ -438,7 +491,6 @@ static int interface(struct state *state, int argc, char **argv) goto err; } break; - case 'c': case 'D': if (rest_argc != 1) { fprintf(stderr, @@ -448,13 +500,20 @@ static int interface(struct state *state, int argc, char **argv) goto err; } break; + case 'c': + ret = interface_parse_create_params(rest_argc, rest_argv, + &create_params); + if (ret) { + interface_usage(); + goto err; + } default: break; }

switch (rest_argv[0][0]) { case 'c': - ret = create_interface(state->mesh_iface); + ret = create_interface(state->mesh_iface, &create_params); if (ret < 0) { fprintf(stderr, "Error - failed to add create batman-adv interface: %s\n", @@ -478,7 +537,7 @@ static int interface(struct state *state, int argc, char **argv) /* get index of batman-adv interface - or try to create it */ ifmaster = if_nametoindex(state->mesh_iface); if (!manual_mode && !ifmaster && rest_argv[0][0] == 'a') { - ret = create_interface(state->mesh_iface); + ret = create_interface(state->mesh_iface, &create_params); if (ret < 0) { fprintf(stderr, "Error - failed to create batman-adv interface: %s\n", diff --git a/man/batctl.8 b/man/batctl.8 index 1737e17..de84ffc 100644 --- a/man/batctl.8 +++ b/man/batctl.8 @@ -60,9 +60,11 @@ In order to add or delete interfaces specify "add" or "del" as first argument an add or delete. Multiple interfaces can be specified. The "-M" option tells batctl to not automatically create the batman-adv interface on "add". It can also be used to suppress the warning about the manual destruction when "del" removed all interfaces which belonged to it. -.IP "[\fBmeshif <netdev>\fP] \fBinterface\fP|\fBif\fP [\fBcreate\fP|\fBdestroy\fP]" -A batman-adv interface without attached interfaces can be created using "create". The parameter "destroy" can be used to -free all attached interfaces and remove batman-adv interface. +.IP "[\fBmeshif <netdev>\fP] \fBinterface\fP|\fBif\fP \fBcreate\fP [\fBrouting_algo|ra RA_NAME\fP]" +A batman-adv interface without attached interfaces can be created using "create". The parameter routing_algo +can be used to overwrite the (default) routing algorithm. +.IP "[\fBmeshif <netdev>\fP] \fBinterface\fP|\fBif\fP \fBdestroy\fP" +Remove all attached interfaces and destroy the batman-adv interface. .br .IP "[\fBmeshif <netdev>\fP] \fBorig_interval\fP|\fBit\fP [\fBinterval\fP]" If no parameter is given the current originator interval setting is displayed otherwise the parameter is used to set the