| Message ID | 20110220.140450.48516784.davem@davemloft.net |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | David Miller |
| Headers | show |
On 20/02/11 23:04, David Miller wrote: > > Install a socket filter to reduce the pure netlink overhead. > > Unfortunately the libmnl library does not provide a way to > set socket options that are of level other than SOL_NETLINK. > > So we hack it by knowing some things about libmnl internals. > > Signed-off-by: David S. Miller <davem@davemloft.net> > --- > > The knowledge of libmnl internals is unfortunate, but there > is currently no other way to do this. > > route_bench.c | 33 +++++++++++++++++++++++++-------- > 1 files changed, 25 insertions(+), 8 deletions(-) > > diff --git a/route_bench.c b/route_bench.c > index c75ea45..6c6b525 100644 > --- a/route_bench.c > +++ b/route_bench.c > @@ -22,6 +22,17 @@ > #include <linux/if.h> > #include <linux/if_link.h> > #include <linux/rtnetlink.h> > +#include <linux/filter.h> > + > +/* XXX Ugly knowledge of internals, but there is currently no way > + * XXX provided by the libmnl library to set socket options that are > + * XXX of level other than SOL_NETLINK. And we need to set one of > + * XXX level SOL_SOCKET to install the socket filter. > + */ > +struct mnl_socket { > + int fd; > + struct sockaddr_nl addr; > +}; > > static int usage(void) > { > @@ -139,8 +150,10 @@ static int do_bench(int count, in_addr_t src_addr, in_addr_t dst_addr, > unsigned int mark, unsigned int iif) > { > char send_buf[MNL_SOCKET_BUFFER_SIZE]; > - char recv_buf[MNL_SOCKET_BUFFER_SIZE]; > unsigned int min, sec, frac, tmp; > + struct sock_filter insns = { .code = BPF_RET | BPF_K, > + .k = 0 }; > + struct sock_fprog filter = { .len = 1, .filter = &insns, }; > struct bench_state *s = &state; > struct timeval start_time; > struct timeval end_time; > @@ -148,7 +161,7 @@ static int do_bench(int count, in_addr_t src_addr, in_addr_t dst_addr, > struct nlmsghdr *nlh; > unsigned int portid; > struct rtmsg *rtm; > - int i; > + int i, err; > > init_bench_state(s); > > @@ -165,10 +178,15 @@ static int do_bench(int count, in_addr_t src_addr, in_addr_t dst_addr, > > portid = mnl_socket_get_portid(nl); > > + err = setsockopt(nl->fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)); > + if (err) { > + perror("setsockopt"); > + return -1; > + } > + You can use: extern int mnl_socket_get_fd(const struct mnl_socket *nl); Thus, you can invoke setsockopt directly ;-). -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/route_bench.c b/route_bench.c index c75ea45..6c6b525 100644 --- a/route_bench.c +++ b/route_bench.c @@ -22,6 +22,17 @@ #include <linux/if.h> #include <linux/if_link.h> #include <linux/rtnetlink.h> +#include <linux/filter.h> + +/* XXX Ugly knowledge of internals, but there is currently no way + * XXX provided by the libmnl library to set socket options that are + * XXX of level other than SOL_NETLINK. And we need to set one of + * XXX level SOL_SOCKET to install the socket filter. + */ +struct mnl_socket { + int fd; + struct sockaddr_nl addr; +}; static int usage(void) { @@ -139,8 +150,10 @@ static int do_bench(int count, in_addr_t src_addr, in_addr_t dst_addr, unsigned int mark, unsigned int iif) { char send_buf[MNL_SOCKET_BUFFER_SIZE]; - char recv_buf[MNL_SOCKET_BUFFER_SIZE]; unsigned int min, sec, frac, tmp; + struct sock_filter insns = { .code = BPF_RET | BPF_K, + .k = 0 }; + struct sock_fprog filter = { .len = 1, .filter = &insns, }; struct bench_state *s = &state; struct timeval start_time; struct timeval end_time; @@ -148,7 +161,7 @@ static int do_bench(int count, in_addr_t src_addr, in_addr_t dst_addr, struct nlmsghdr *nlh; unsigned int portid; struct rtmsg *rtm; - int i; + int i, err; init_bench_state(s); @@ -165,10 +178,15 @@ static int do_bench(int count, in_addr_t src_addr, in_addr_t dst_addr, portid = mnl_socket_get_portid(nl); + err = setsockopt(nl->fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)); + if (err) { + perror("setsockopt"); + return -1; + } + gettimeofday(&start_time, NULL); for (i = 0; i < count; i++) { unsigned int seq; - int ret; nlh = mnl_nlmsg_put_header(send_buf); nlh->nlmsg_type = RTM_GETROUTE; @@ -197,11 +215,10 @@ static int do_bench(int count, in_addr_t src_addr, in_addr_t dst_addr, perror("mnl_socket_sendto"); return -1; } - ret = mnl_socket_recvfrom(nl, recv_buf, sizeof(recv_buf)); - if (ret < 0) { - perror("mnl_sock_recvfrom"); - return -1; - } + + /* No need to do a receive, as the socket filter rejects + * all packets. + */ advance_bench_state(s); }
Install a socket filter to reduce the pure netlink overhead. Unfortunately the libmnl library does not provide a way to set socket options that are of level other than SOL_NETLINK. So we hack it by knowing some things about libmnl internals. Signed-off-by: David S. Miller <davem@davemloft.net> --- The knowledge of libmnl internals is unfortunate, but there is currently no other way to do this. route_bench.c | 33 +++++++++++++++++++++++++-------- 1 files changed, 25 insertions(+), 8 deletions(-)