nexoniarz/SchOS
nexoniarz/SchOS
Watch
1
0
Fork
You've already forked SchOS
 0
Code Issues Pull requests Projects Releases 1 Packages Wiki Activity Actions

Netlink datagrams can be measured, credentials name their sender

Browse source 
Epiphany's main thread spun at 100% on GLib's network monitor. GLib
sizes each netlink datagram with recvmsg(MSG_PEEK|MSG_TRUNC) and no
buffer; that answered 0, GLib read 0 bytes, the answer stayed queued and
poll() said readable again, forever. recvmsg on netlink now peeks
without consuming and with MSG_TRUNC returns what is waiting. A drained
netlink socket also no longer reports hangup -- it has no peer, and
sock_hup took that for a closed one.

SCM_CREDENTIALS under SO_PASSCRED named the process that created the far
end, not the one that wrote to it. For a socketpair those differ: WebKit
makes the pair, hands one end to a child, and learns the child's pid
from the credentials on its first byte. Each end now records its last
writer.

LDLS: napi_consume_skb frees the skb. r8169 frees every sent frame with
it, and as a stub it leaked one per frame until the DMA heap ran out.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S1giNvrHTrPMPw7V6x1kQ4
This commit is contained in:
Nexoniarz 2026-10-25 14:58:14 +01:00
commit 3676036762
5 changed files with 120 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

4
include/core/defs.h
View file

@ -533,6 +533,10 @@ int sockname_inet(struct socket*, int peer, uint *addr, ushort *port
#define SOCK_ABSTRACT_DEV 0xFFFFFFFFu // no filesystem has it; see unix.c
int sockreadable(struct socket*);
int sock_hup(struct socket*);
uint socknl_pending(struct socket*);
int sock_sendercred(struct socket*, int*, uint*, uint*);
int socknl_copy(struct socket*, uint, char*, int);
void socknl_take(struct socket*, uint);
int sock_shutdown(struct socket*, int how);
int sockpair(struct socket **a, struct socket **b);
const char* sockname(struct socket*);

7
include/net/socket.h
View file

@ -362,6 +362,13 @@ struct socket {
// the listener -- which is what Linux records too.
int cred_pid;
uint cred_uid, cred_gid;
// Who last wrote at this end, for SCM_CREDENTIALS on the other. Not the
// same thing as cred_*: one end of a socketpair is made by the parent and
// written by the child it is handed to, and WebKit learns its children's
// pids from exactly that. 0 until the first write.
int tx_pid;
uint tx_uid, tx_gid;
};
#endif