On Mon, Jun 13, 2016 at 02:37:22PM +0000, Fabien Siron wrote: > This commit introduces a general socket netlink parser which prints > the header and a string for the remaining part of the buffer. It doesn't > handle all the netlink flags and types because the parser needs more > information. It will be done soon. > > * net.c (get_family): New function. > (do_msghdr): Call decode_iov_netlink. > * netlink.c: New file. > (decode_netlink): New function. > (decode_iov_netlink): New function. > * defs.h (decode_iov_netlink): Add. > * Makefile.am (strace_SOURCES): Add netlink.c. > --- > Makefile.am | 1 + > defs.h | 4 +++ > net.c | 60 ++++++++++++++++++++++++++++----- > netlink.c | 93 > +++++++++++++++++++++++++++++++++++++++++++++++++++ > util.c | 2 +- > xlat/netlink_flags.in | 6 ++++ > xlat/netlink_types.in | 4 +++ > 7 files changed, 161 insertions(+), 9 deletions(-) > create mode 100644 netlink.c > create mode 100644 xlat/netlink_flags.in > create mode 100644 xlat/netlink_types.in > > diff --git a/Makefile.am b/Makefile.am > index 77e0cc8..ab0e200 100644 > --- a/Makefile.am > +++ b/Makefile.am > @@ -156,6 +156,7 @@ strace_SOURCES = \ > mtd.c \ > native_defs.h \ > net.c \ > + netlink.c \ > numa.c \ > open.c \ > or1k_atomic.c \ > diff --git a/defs.h b/defs.h > index 594a292..134e0fe 100644 > --- a/defs.h > +++ b/defs.h > @@ -542,6 +542,7 @@ extern const char *signame(const int); > extern void pathtrace_select(const char *); > extern int pathtrace_match(struct tcb *); > extern int getfdpath(struct tcb *, int, char *, unsigned); > +extern int getfdproto(struct tcb *, int); > > extern const char *xlookup(const struct xlat *, const uint64_t); > extern const char *xlat_search(const struct xlat *, const size_t, const > uint64_t); > @@ -651,6 +652,9 @@ extern const char *sprintsigmask_n(const char *, const > void *, unsigned int); > extern void printsignal(int); > extern void tprint_iov(struct tcb *, unsigned long, unsigned long, int > decode_iov); > extern void tprint_iov_upto(struct tcb *, unsigned long, unsigned long, int > decode_iov, unsigned long); > +extern void decode_iov_netlink_or_printaddr(struct tcb *, unsigned long, > + unsigned long, unsigned long); > +extern void decode_netlink_or_printaddr(struct tcb *, unsigned long, > unsigned long);
There are no decode_netlink* functions that don't do printaddr,
so the "_or_printaddr" suffix looks redundant here.
Also, I'd rather rename decode_iov_netlink to decode_netlink_iov.
> extern void tprint_open_modes(unsigned int);
> extern const char *sprint_open_modes(unsigned int);
> extern void print_seccomp_filter(struct tcb *, unsigned long);
> diff --git a/net.c b/net.c
> index 8cc97da..09f375e 100644
> --- a/net.c
> +++ b/net.c
> @@ -297,6 +297,39 @@ printsock(struct tcb *tcp, long addr, int addrlen)
> print_sockaddr(tcp, &addrbuf, addrlen);
> }
>
> +#include "socketutils.h"
> +
> +static void
> +printsockbuf(struct tcb *tcp, int fd, long addr, long addrlen)
> +{
> + int proto = getfdproto(tcp, fd);
This operation costs a few syscalls so it shouldn't be attempted
unless show_fd_path > 1.
> + switch (proto) {
> + case NETLINK:
> + decode_netlink_or_printaddr(tcp, addr, addrlen);
> + break;
> + default:
> + printstr(tcp, addr, addrlen);
> + }
> +}
> +
> +static int
> +get_family(struct tcb *tcp, long addr, int addrlen)
> +{
> + sockaddr_buf_t addrbuf;
> +
> + if (addrlen < 2)
> + return -1;
> + if (addrlen > (int) sizeof(addrbuf))
> + addrlen = sizeof(addrbuf);
> +
> + memset(&addrbuf, 0, sizeof(addrbuf));
> + if (umoven(tcp, addr, addrlen, addrbuf.pad) == -1)
> + return -1;
> +
> + return addrbuf.sa.sa_family;
> +}
As this information has already been fetched by printsock,
why do it the second time in a row?
> +
> #include "xlat/scmvals.h"
> #include "xlat/ip_cmsg_types.h"
>
> @@ -598,8 +631,16 @@ do_msghdr(struct tcb *tcp, struct msghdr *msg, unsigned
> long data_size)
> printsock(tcp, (long)msg->msg_name, msg->msg_namelen);
>
> tprintf(", msg_iov(%lu)=", (unsigned long)msg->msg_iovlen);
> - tprint_iov_upto(tcp, (unsigned long)msg->msg_iovlen,
> - (unsigned long)msg->msg_iov, 1, data_size);
> +#ifdef AF_NETLINK
> + if (get_family(tcp, (long) msg->msg_name, msg->msg_namelen)
> + == AF_NETLINK)
> + decode_iov_netlink_or_printaddr(tcp,
> + (unsigned long) msg->msg_iovlen,
> + (unsigned long) msg->msg_iov, data_size);
> + else
> +#endif
> + tprint_iov_upto(tcp, (unsigned long)msg->msg_iovlen,
> + (unsigned long)msg->msg_iov, 1, data_size);
>
> #ifdef HAVE_STRUCT_MSGHDR_MSG_CONTROL
> tprintf(", msg_controllen=%lu", (unsigned long)msg->msg_controllen);
> @@ -886,7 +927,7 @@ SYS_FUNC(send)
> {
> printfd(tcp, tcp->u_arg[0]);
> tprints(", ");
> - printstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
> + printsockbuf(tcp, tcp->u_arg[0], tcp->u_arg[1], tcp->u_arg[2]);
> tprintf(", %lu, ", tcp->u_arg[2]);
> /* flags */
> printflags(msg_flags, tcp->u_arg[3], "MSG_???");
> @@ -898,7 +939,7 @@ SYS_FUNC(sendto)
> {
> printfd(tcp, tcp->u_arg[0]);
> tprints(", ");
> - printstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
> + printsockbuf(tcp, tcp->u_arg[0], tcp->u_arg[1], tcp->u_arg[2]);
> tprintf(", %lu, ", tcp->u_arg[2]);
> /* flags */
> printflags(msg_flags, tcp->u_arg[3], "MSG_???");
> @@ -947,10 +988,11 @@ SYS_FUNC(recv)
> printfd(tcp, tcp->u_arg[0]);
> tprints(", ");
> } else {
> - if (syserror(tcp))
> + if (syserror(tcp)) {
> printaddr(tcp->u_arg[1]);
> - else
> - printstr(tcp, tcp->u_arg[1], tcp->u_rval);
> + } else
> + printsockbuf(tcp, tcp->u_arg[0], tcp->u_arg[1],
> + tcp->u_rval);
>
> tprintf(", %lu, ", tcp->u_arg[2]);
> printflags(msg_flags, tcp->u_arg[3], "MSG_???");
> @@ -966,11 +1008,13 @@ SYS_FUNC(recvfrom)
> printfd(tcp, tcp->u_arg[0]);
> tprints(", ");
> } else {
> +
> /* buf */
> if (syserror(tcp)) {
> printaddr(tcp->u_arg[1]);
> } else {
> - printstr(tcp, tcp->u_arg[1], tcp->u_rval);
> + printsockbuf(tcp, tcp->u_arg[0], tcp->u_arg[1],
> + tcp->u_rval);
> }
> /* len */
> tprintf(", %lu, ", tcp->u_arg[2]);
> diff --git a/netlink.c b/netlink.c
> new file mode 100644
> index 0000000..738c639
> --- /dev/null
> +++ b/netlink.c
> @@ -0,0 +1,93 @@
> +/*
> + * Copyright (c) 2016 Fabien Siron <fabien.si...@epita.fr>
> + * All rights reserved.
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + * notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + * notice, this list of conditions and the following disclaimer in the
> + * documentation and/or other materials provided with the distribution.
> + * 3. The name of the author may not be used to endorse or promote products
> + * derived from this software without specific prior written permission.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
> + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
> + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
> + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
> + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
> + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
> + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
> + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
> + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
> + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
> + */
> +
> +#include "defs.h"
> +#include <sys/socket.h>
> +#if defined(HAVE_LINUX_NETLINK_H)
> +# include <linux/netlink.h>
> +#endif
socketutils.c already includes <linux/netlink.h> unconditionally.
> +#include "xlat/netlink_flags.h"
> +#include "xlat/netlink_types.h"
> +
> +void
> +decode_netlink_or_printaddr(struct tcb *tcp, unsigned long addr,
> + unsigned long size)
> +{
> +#ifdef AF_NETLINK
socketutils.c already uses AF_NETLINK unconditionally.
> + struct nlmsghdr nlmsghdr;
> + memset(&nlmsghdr, 0, sizeof(nlmsghdr));
You can assume that compiler supports C99.
> + if (umoven(tcp, addr, sizeof(nlmsghdr), &nlmsghdr) == -1)
> + return;
Can "size" be lower than sizeof(nlmsghdr)?
Note that this function has name decode_netlink_or_printaddr but it
doesn't do any printaddr.
Looks like umove_or_printaddr is more appropriate here.
> + tprintf("{{len=%u, type=", nlmsghdr.nlmsg_len);
> + if (nlmsghdr.nlmsg_type < NLMSG_MIN_TYPE)
> + printxval(netlink_types, nlmsghdr.nlmsg_type, "NLMSG_???");
> + else
> + tprintf("%u", nlmsghdr.nlmsg_type);
printxval can be invoked here unconditionally.
> + tprints(", flags=");
> + printflags(netlink_flags, nlmsghdr.nlmsg_flags, "NLM_F_???");
> + /* manage get/new requests */
> +
> + tprintf(", seq=%u, pid=%u}, ", nlmsghdr.nlmsg_seq,
> + nlmsghdr.nlmsg_pid);
> +
> + if (size - sizeof(struct nlmsghdr) > 0)
> + printstr(tcp, addr + sizeof(struct nlmsghdr),
> + size - sizeof(struct nlmsghdr));
An extra comma will be printed when this condition is false.
> + tprints("}");
> +
> +#else
> + printaddr(addr);
> +#endif
> +}
> +
> +void
> +decode_iov_netlink_or_printaddr(struct tcb *tcp, unsigned long len,
> + unsigned long addr, unsigned long data_size)
> +{
> + unsigned long iov[2];
> + unsigned int i;
> +
> + if (!len) {
> + tprints("[]");
> + return;
> + }
> +
> + for (i = 0; i < len; ++i) {
> + if(umove_or_printaddr(tcp, addr + i * sizeof(iov), iov))
> + return;
> +
> + if (iov[1] < sizeof(struct nlmsghdr)) {
> + tprintf("len(%lu)", len);
> + printaddr(addr);
> + return;
> + }
> + decode_netlink_or_printaddr(tcp, iov[0], iov[1]);
> + }
> +}
Please do not reinvent print_array. See e.g. tprint_iov_upto.
--
ldv
pgpP7UK51eJuk.pgp
Description: PGP signature
------------------------------------------------------------------------------ What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports. https://ad.doubleclick.net/ddm/clk/305295220;132659582;e
_______________________________________________ Strace-devel mailing list Strace-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/strace-devel
