o Introduce a notion of "not ready" mbufs in socket buffers. These
mbufs are now being populated by some I/O in background and are
referenced outside. This forces following implications:
- An mbuf which is "not ready" can't be taken out of the buffer.
- An mbuf that is behind a "not ready" in the queue neither.
- If sockbet buffer is flushed, then "not ready" mbufs shouln't be
freed.
o In struct sockbuf the sb_cc field is split into sb_ccc and sb_acc.
The sb_ccc stands for ""claimed character count", or "committed
character count". And the sb_acc is "available character count".
Consumers of socket buffer API shouldn't already access them directly,
but use sbused() and sbavail() respectively.
o Not ready mbufs are marked with M_NOTREADY, and ready but blocked ones
with M_BLOCKED.
o New field sb_fnrdy points to the first not ready mbuf, to avoid linear
search.
o New function sbready() is provided to activate certain amount of mbufs
in a socket buffer.
A special note on SCTP:
SCTP has its own sockbufs. Unfortunately, FreeBSD stack doesn't yet
allow protocol specific sockbufs. Thus, SCTP does some hacks to make
itself compatible with FreeBSD: it manages sockbufs on its own, but keeps
sb_cc updated to inform the stack of amount of data in them. The new
notion of "not ready" data isn't supported by SCTP. Instead, only a
mechanical substitute is done: s/sb_cc/sb_ccc/.
A proper solution would be to take away struct sockbuf from struct
socket and allow protocols to implement their own socket buffers, like
SCTP already does. This was discussed with rrs@.
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
The index() and rindex() functions were marked LEGACY in the 2001
revision of POSIX and were subsequently removed from the 2008 revision.
The strchr() and strrchr() functions are part of the C standard.
This makes the source code a lot more consistent, as most of these C
files also call into other str*() routines. In fact, about a dozen
already perform strchr() calls.
is in accordance with the information provided at
ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
Also add $FreeBSD$ to a few files to keep svn happy.
Discussed with: imp, rwatson
certain flags that should have been in inp_flags ended up in inp_vflag,
meaning that they were inconsistently locked, and in one case,
interpreted. Move the following flags from inp_vflag to gaps in the
inp_flags space (and clean up the inp_flags constants to make gaps
more obvious to future takers):
INP_TIMEWAIT
INP_SOCKREF
INP_ONESBCAST
INP_DROPPED
Some aspects of this change have no effect on kernel ABI at all, as these
are UDP/TCP/IP-internal uses; however, netstat and sockstat detect
INP_TIMEWAIT when listing TCP sockets, so any MFC will need to take this
into account.
MFC after: 1 week (or after dependencies are MFC'd)
Reviewed by: bz
we set and use xtp; if idx is 1, we set and use xip; the other cases
are impossible. However, GCC cannot see that xip and xtp are always
initialized before use because they are initialized and used in
different if/else blocks. So setting them to NULL at the very
beginning won't hurt.
not very usefully, in all other displays). This was the original point
of the PR.
Move the load average up by 2 so that it starts in row 0 for all windows
(2 lines above it were wasted for all other windows except vmstat).
Move everything below it up by 2 or 3 (3 for icmp and icmp6 which had
an extra blank line due from not compensating for the foot-shooting in
note (3); only ip and ip6 compensated). Reduce the magic numbers related
to this.
Notes by the submitter:
%%%
1. All the subwin() calls are identical using #define MAINWIN_ROW 3
(systat.h).
2. The load average is at the top of the window.
3. Each display starts on the fourth line. I made changes to those
displays that shifted the start line (i.e., icmp). This entailed a
lot of changes within the comments at the top of those displays.
4. For ip6, I shifted the "Input next-header histogram" column down one
row to separate it from "IPv6 Output". I raised "bad scope packets"
and "address selection failed" up one row to stay with "IPv6 Input"
(valid?). They were down one row to probably line up at the bottom,
but I think they should stick with their fellow items in a column.
5. I condensed ifstat a bit. It had a lot of empty rows.
%%%
Submitted by: Se=E1n Farley <sean-freebsd at farley dot org>
PR: bin/81874
non-default but reasonable values of hz this member overflowed,
breaking NFS over UDP.
Also, as long as I'm plowing up struct sockbuf ... Change certain
members from u_long/long to u_int/int in order to reduce wasted
space on 64-bit machines. This change was requested by Andrew
Gallatin.
Netstat and systat need to be rebuilt. I am incrementing
__FreeBSD_version in case any ports need to change.
and compiler warnings.
The data for network statistics are still obtained via the kvm interface
if systat was started with the needed privileges, otherwise sysctls are
used. The reason for this is that with really many open sockets, the
sysctl method is probably slower, but it systat -netstat is probably not
really usable in either mode under these conditions.
Approved by: rwatson
o Add more checks for buffer overflows
o Use snprintf rather than strcat/cpy and have better checks for max
length exceeded.
Most of these changes are not exploitable buffer overruns, but it never
hurts to be safe.
Inspired by and obtained from: OpenBSD
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
