Date: Wed, 10 Aug 2022 18:10:27 GMT From: Gleb Smirnoff <glebius@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 8f5a0a2e4f31 - main - sockets: provide solisten_clone(), solisten_enqueue() Message-ID: <202208101810.27AIARKE044004@gitrepo.freebsd.org>
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The branch main has been updated by glebius: URL: https://cgit.FreeBSD.org/src/commit/?id=8f5a0a2e4f315a03caaa2d51efdcf837e303e510 commit 8f5a0a2e4f315a03caaa2d51efdcf837e303e510 Author: Gleb Smirnoff <glebius@FreeBSD.org> AuthorDate: 2022-08-10 18:09:34 +0000 Commit: Gleb Smirnoff <glebius@FreeBSD.org> CommitDate: 2022-08-10 18:09:34 +0000 sockets: provide solisten_clone(), solisten_enqueue() as alternative KPI to sonewconn(). The latter has three stages: - check the listening socket queue limits - allocate a new socket - call into protocol attach method - link the new socket into the listen queue of the listening socket The attach method, originally designed for a creation of socket by the socket(2) syscall has slightly different semantics than attach of a socket cloned by listener. Make it possible for protocols to call into the first stage, then perform a different attach, and then call into the final stage. The first stage, that checks limits and clones a socket is called solisten_clone(), and the function that enqueues the socket is solisten_enqueue(). Reviewed by: tuexen Differential revision: https://reviews.freebsd.org/D36063 --- sys/kern/uipc_socket.c | 86 +++++++++++++++++++++++++++++++++++--------------- sys/sys/socketvar.h | 3 ++ 2 files changed, 64 insertions(+), 25 deletions(-) diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c index 8ecf83d30e28..73725efceb2d 100644 --- a/sys/kern/uipc_socket.c +++ b/sys/kern/uipc_socket.c @@ -587,16 +587,17 @@ SYSCTL_TIMEVAL_SEC(_kern_ipc, OID_AUTO, sooverinterval, CTLFLAG_RW, "Delay in seconds between warnings for listen socket overflows"); /* - * When an attempt at a new connection is noted on a socket which accepts - * connections, sonewconn is called. If the connection is possible (subject - * to space constraints, etc.) then we allocate a new structure, properly - * linked into the data structure of the original socket, and return this. - * Connstatus may be 0, or SS_ISCONFIRMING, or SS_ISCONNECTED. + * When an attempt at a new connection is noted on a socket which supports + * accept(2), the protocol has two options: + * 1) Call legacy sonewconn() function, which would call protocol attach + * method, same as used for socket(2). + * 2) Call solisten_clone(), do attach that is specific to a cloned connection, + * and then call solisten_enqueue(). * * Note: the ref count on the socket is 0 on return. */ struct socket * -sonewconn(struct socket *head, int connstatus) +solisten_clone(struct socket *head) { struct sbuf descrsb; struct socket *so; @@ -701,20 +702,27 @@ sonewconn(struct socket *head, int connstatus) } KASSERT(sbuf_len(&descrsb) > 0, ("%s: sbuf creation failed", __func__)); + /* + * Preserve the historic listen queue overflow log + * message, that starts with "sonewconn:". It has + * been known to sysadmins for years and also test + * sys/kern/sonewconn_overflow checks for it. + */ if (head->so_cred == 0) { - log(LOG_DEBUG, - "%s: pcb %p (%s): Listen queue overflow: " - "%i already in queue awaiting acceptance " - "(%d occurrences)\n", - __func__, head->so_pcb, sbuf_data(&descrsb), + log(LOG_DEBUG, "sonewconn: pcb %p (%s): " + "Listen queue overflow: %i already in " + "queue awaiting acceptance (%d " + "occurrences)\n", head->so_pcb, + sbuf_data(&descrsb), qlen, overcount); } else { - log(LOG_DEBUG, "%s: pcb %p (%s): Listen queue overflow: " + log(LOG_DEBUG, "sonewconn: pcb %p (%s): " + "Listen queue overflow: " "%i already in queue awaiting acceptance " "(%d occurrences), euid %d, rgid %d, jail %s\n", - __func__, head->so_pcb, sbuf_data(&descrsb), - qlen, overcount, - head->so_cred->cr_uid, head->so_cred->cr_rgid, + head->so_pcb, sbuf_data(&descrsb), qlen, + overcount, head->so_cred->cr_uid, + head->so_cred->cr_rgid, head->so_cred->cr_prison ? head->so_cred->cr_prison->pr_name : "not_jailed"); @@ -758,25 +766,52 @@ sonewconn(struct socket *head, int connstatus) __func__, head->so_pcb); return (NULL); } + so->so_rcv.sb_lowat = head->sol_sbrcv_lowat; + so->so_snd.sb_lowat = head->sol_sbsnd_lowat; + so->so_rcv.sb_timeo = head->sol_sbrcv_timeo; + so->so_snd.sb_timeo = head->sol_sbsnd_timeo; + so->so_rcv.sb_flags = head->sol_sbrcv_flags & SB_AUTOSIZE; + so->so_snd.sb_flags = head->sol_sbsnd_flags & SB_AUTOSIZE; 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; } - /* Socket starts with a reference from the listen queue. */ - refcount_init(&so->so_count, 1); + + return (so); +} + +/* Connstatus may be 0, or SS_ISCONFIRMING, or SS_ISCONNECTED. */ +struct socket * +sonewconn(struct socket *head, int connstatus) +{ + struct socket *so; + + if ((so = solisten_clone(head)) == NULL) + return (NULL); + if ((*so->so_proto->pr_usrreqs->pru_attach)(so, 0, NULL)) { - MPASS(refcount_release(&so->so_count)); sodealloc(so); log(LOG_DEBUG, "%s: pcb %p: pru_attach() failed\n", __func__, head->so_pcb); return (NULL); } - so->so_rcv.sb_lowat = head->sol_sbrcv_lowat; - so->so_snd.sb_lowat = head->sol_sbsnd_lowat; - so->so_rcv.sb_timeo = head->sol_sbrcv_timeo; - so->so_snd.sb_timeo = head->sol_sbsnd_timeo; - so->so_rcv.sb_flags |= head->sol_sbrcv_flags & SB_AUTOSIZE; - so->so_snd.sb_flags |= head->sol_sbsnd_flags & SB_AUTOSIZE; + + solisten_enqueue(so, connstatus); + + return (so); +} + +/* + * Enqueue socket cloned by solisten_clone() to the listen queue of the + * listener it has been cloned from. + */ +void +solisten_enqueue(struct socket *so, int connstatus) +{ + struct socket *head = so->so_listen; + + MPASS(refcount_load(&so->so_count) == 0); + refcount_init(&so->so_count, 1); SOLISTEN_LOCK(head); if (head->sol_accept_filter != NULL) @@ -815,13 +850,14 @@ sonewconn(struct socket *head, int connstatus) head->sol_incqlen++; SOLISTEN_UNLOCK(head); } - return (so); } #if defined(SCTP) || defined(SCTP_SUPPORT) /* * Socket part of sctp_peeloff(). Detach a new socket from an * association. The new socket is returned with a reference. + * + * XXXGL: reduce copy-paste with solisten_clone(). */ struct socket * sopeeloff(struct socket *head) diff --git a/sys/sys/socketvar.h b/sys/sys/socketvar.h index c496239f92bc..ed797c6d6239 100644 --- a/sys/sys/socketvar.h +++ b/sys/sys/socketvar.h @@ -474,7 +474,10 @@ int solisten(struct socket *so, int backlog, struct thread *td); void solisten_proto(struct socket *so, int backlog); void solisten_proto_abort(struct socket *so); int solisten_proto_check(struct socket *so); +void solisten_enqueue(struct socket *, int); int solisten_dequeue(struct socket *, struct socket **, int); +struct socket * + solisten_clone(struct socket *); struct socket * sonewconn(struct socket *head, int connstatus); struct socket *
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