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sockets: enable protocol specific socket buffers

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Split struct sockbuf into common shared fields and protocol specific
union, where protocols are free to implement whatever buffer they
want.  Such protocols should mark themselves with PR_SOCKBUF and are
expected to initialize their buffers in their pr_attach and tear
them down in pr_detach.

Reviewed by:		markj
Differential revision:	https://reviews.freebsd.org/D35299
This commit is contained in:
Gleb Smirnoff 2022-06-24 09:09:10 -07:00
parent 315167c0de
commit a4fc41423f
3 changed files with 67 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
sys/kern/uipc_socket.c
View File

@ -418,8 +418,6 @@ soalloc(struct vnet *vnet)
* a feature to change class of an existing lock, so we use DUPOK.
*/
mtx_init(&so->so_lock, "socket", NULL, MTX_DEF | MTX_DUPOK);
so->so_snd.sb_mtx = &so->so_snd_mtx;
so->so_rcv.sb_mtx = &so->so_rcv_mtx;
mtx_init(&so->so_snd_mtx, "so_snd", NULL, MTX_DEF);
mtx_init(&so->so_rcv_mtx, "so_rcv", NULL, MTX_DEF);
so->so_rcv.sb_sel = &so->so_rdsel;
@ -557,6 +555,10 @@ socreate(int dom, struct socket **aso, int type, int proto,
so_rdknl_assert_lock);
knlist_init(&so->so_wrsel.si_note, so, so_wrknl_lock, so_wrknl_unlock,
so_wrknl_assert_lock);
if ((prp->pr_flags & PR_SOCKBUF) == 0) {
so->so_snd.sb_mtx = &so->so_snd_mtx;
so->so_rcv.sb_mtx = &so->so_rcv_mtx;
}
/*
* Auto-sizing of socket buffers is managed by the protocols and
* the appropriate flags must be set in the pru_attach function.
@ -756,6 +758,10 @@ sonewconn(struct socket *head, int connstatus)
__func__, head->so_pcb);
return (NULL);
}
if ((so->so_proto->pr_flags & PR_SOCKBUF) == 0) {
so->so_snd.sb_mtx = &so->so_snd_mtx;
so->so_rcv.sb_mtx = &so->so_rcv_mtx;
}
if ((*so->so_proto->pr_usrreqs->pru_attach)(so, 0, NULL)) {
sodealloc(so);
log(LOG_DEBUG, "%s: pcb %p: pru_attach() failed\n",
@ -1207,7 +1213,7 @@ sofree(struct socket *so)
* socket exist anywhere else in the stack. Therefore, no locks need
* to be acquired or held.
*/
if (!SOLISTENING(so)) {
if (!(pr->pr_flags & PR_SOCKBUF) && !SOLISTENING(so)) {
sbdestroy(so, SO_SND);
sbdestroy(so, SO_RCV);
}

3
sys/sys/protosw.h
View File

@ -114,6 +114,8 @@ struct protosw {
* and the protocol understands the MSG_EOF flag. The first property is
* is only relevant if PR_CONNREQUIRED is set (otherwise sendto is allowed
* anyhow).
* PR_SOCKBUF requires protocol to initialize and destroy its socket buffers
* in its pr_attach and pr_detach.
*/
#define PR_ATOMIC 0x01 /* exchange atomic messages only */
#define PR_ADDR 0x02 /* addresses given with messages */
@ -123,6 +125,7 @@ struct protosw {
#define PR_IMPLOPCL 0x20 /* implied open/close */
#define PR_LASTHDR 0x40 /* enforce ipsec policy; last header */
#define PR_CAPATTACH 0x80 /* socket can attach in cap mode */
#define PR_SOCKBUF 0x100 /* private implementation of buffers */
/*
* In earlier BSD network stacks, a single pr_usrreq() function pointer was

86
sys/sys/sockbuf.h
View File

@ -75,41 +75,65 @@ struct thread;
struct selinfo;
/*
* Variables for socket buffering.
* Socket buffer
*
* Locking key to struct sockbuf:
* (a) locked by SOCKBUF_LOCK().
* A buffer starts with the fields that are accessed by I/O multiplexing
* APIs like select(2), kevent(2) or AIO and thus are shared between different
* buffer implementations. They are protected by the SOCK_RECVBUF_LOCK()
* or SOCK_SENDBUF_LOCK() of the owning socket.
*
* XXX: sb_acc, sb_ccc and sb_mbcnt shall become implementation specific
* methods.
*
* Protocol specific implementations follow in a union.
*/
struct sockbuf {
struct mtx *sb_mtx; /* sockbuf lock */
struct selinfo *sb_sel; /* process selecting read/write */
short sb_state; /* (a) socket state on sockbuf */
short sb_flags; /* (a) flags, see above */
struct mbuf *sb_mb; /* (a) the mbuf chain */
struct mbuf *sb_mbtail; /* (a) the last mbuf in the chain */
struct mbuf *sb_lastrecord; /* (a) first mbuf of last
* record in socket buffer */
struct mbuf *sb_sndptr; /* (a) pointer into mbuf chain */
struct mbuf *sb_fnrdy; /* (a) pointer to first not ready buffer */
u_int sb_sndptroff; /* (a) byte offset of ptr into chain */
u_int sb_acc; /* (a) available chars in buffer */
u_int sb_ccc; /* (a) claimed chars in buffer */
u_int sb_hiwat; /* (a) max actual char count */
u_int sb_mbcnt; /* (a) chars of mbufs used */
u_int sb_mbmax; /* (a) max chars of mbufs to use */
u_int sb_ctl; /* (a) non-data chars in buffer */
u_int sb_tlscc; /* (a) TLS chain characters */
u_int sb_tlsdcc; /* (a) TLS characters being decrypted */
int sb_lowat; /* (a) low water mark */
sbintime_t sb_timeo; /* (a) timeout for read/write */
struct mbuf *sb_mtls; /* (a) TLS mbuf chain */
struct mbuf *sb_mtlstail; /* (a) last mbuf in TLS chain */
int (*sb_upcall)(struct socket *, void *, int); /* (a) */
void *sb_upcallarg; /* (a) */
uint64_t sb_tls_seqno; /* (a) TLS seqno */
struct ktls_session *sb_tls_info; /* (a + b) TLS state */
TAILQ_HEAD(, kaiocb) sb_aiojobq; /* (a) pending AIO ops */
struct task sb_aiotask; /* AIO task */
short sb_state; /* socket state on sockbuf */
short sb_flags; /* flags, see above */
u_int sb_acc; /* available chars in buffer */
u_int sb_ccc; /* claimed chars in buffer */
u_int sb_mbcnt; /* chars of mbufs used */
u_int sb_ctl; /* non-data chars in buffer */
u_int sb_hiwat; /* max actual char count */
u_int sb_lowat; /* low water mark */
u_int sb_mbmax; /* max chars of mbufs to use */
sbintime_t sb_timeo; /* timeout for read/write */
int (*sb_upcall)(struct socket *, void *, int);
void *sb_upcallarg;
TAILQ_HEAD(, kaiocb) sb_aiojobq; /* pending AIO ops */
struct task sb_aiotask; /* AIO task */
union {
/*
* Classic BSD one-size-fits-all socket buffer, capable of
* doing streams and datagrams. The stream part is able
* to perform special features:
* - not ready data (sendfile)
* - TLS
*/
struct {
/* compat: sockbuf lock pointer */
struct mtx *sb_mtx;
/* first and last mbufs in the chain */
struct mbuf *sb_mb;
struct mbuf *sb_mbtail;
/* first mbuf of last record in socket buffer */
struct mbuf *sb_lastrecord;
/* pointer to data to send next (TCP */
struct mbuf *sb_sndptr;
/* pointer to first not ready buffer */
struct mbuf *sb_fnrdy;
/* byte offset of ptr into chain, used with sb_sndptr */
u_int sb_sndptroff;
/* TLS */
u_int sb_tlscc; /* TLS chain characters */
u_int sb_tlsdcc; /* characters being decrypted */
struct mbuf *sb_mtls; /* TLS mbuf chain */
struct mbuf *sb_mtlstail; /* last mbuf in TLS chain */
uint64_t sb_tls_seqno; /* TLS seqno */
struct ktls_session *sb_tls_info; /* TLS state */
};
};
};
#endif /* defined(_KERNEL) || defined(_WANT_SOCKET) */