Marcelo Ricardo Leitner
2020-May-13 18:03 UTC
[Ocfs2-devel] [PATCH 32/33] sctp: add sctp_sock_get_primary_addr
On Wed, May 13, 2020 at 08:26:47AM +0200, Christoph Hellwig wrote:> Add a helper to directly get the SCTP_PRIMARY_ADDR sockopt from kernel > space without going through a fake uaccess.Same comment as on the other dlm/sctp patch.> > Signed-off-by: Christoph Hellwig <hch at lst.de> > --- > fs/dlm/lowcomms.c | 11 +++----- > include/net/sctp/sctp.h | 1 + > net/sctp/socket.c | 57 +++++++++++++++++++++++++---------------- > 3 files changed, 39 insertions(+), 30 deletions(-) > > diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c > index 6fa45365666a8..46d2d71b62c57 100644 > --- a/fs/dlm/lowcomms.c > +++ b/fs/dlm/lowcomms.c > @@ -855,10 +855,9 @@ static int tcp_accept_from_sock(struct connection *con) > static int sctp_accept_from_sock(struct connection *con) > { > /* Check that the new node is in the lockspace */ > - struct sctp_prim prim; > + struct sctp_prim prim = { }; > int nodeid; > - int prim_len, ret; > - int addr_len; > + int addr_len, ret; > struct connection *newcon; > struct connection *addcon; > struct socket *newsock; > @@ -876,11 +875,7 @@ static int sctp_accept_from_sock(struct connection *con) > if (ret < 0) > goto accept_err; > > - memset(&prim, 0, sizeof(struct sctp_prim)); > - prim_len = sizeof(struct sctp_prim); > - > - ret = kernel_getsockopt(newsock, IPPROTO_SCTP, SCTP_PRIMARY_ADDR, > - (char *)&prim, &prim_len); > + ret = sctp_sock_get_primary_addr(con->sock->sk, &prim); > if (ret < 0) { > log_print("getsockopt/sctp_primary_addr failed: %d", ret); > goto accept_err; > diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h > index b505fa082f254..c98b1d14db853 100644 > --- a/include/net/sctp/sctp.h > +++ b/include/net/sctp/sctp.h > @@ -618,5 +618,6 @@ static inline bool sctp_newsk_ready(const struct sock *sk) > int sctp_setsockopt_bindx(struct sock *sk, struct sockaddr *kaddrs, > int addrs_size, int op); > void sctp_sock_set_nodelay(struct sock *sk, bool val); > +int sctp_sock_get_primary_addr(struct sock *sk, struct sctp_prim *prim); > > #endif /* __net_sctp_h__ */ > diff --git a/net/sctp/socket.c b/net/sctp/socket.c > index 64c395f7a86d5..39bf8090dbe1e 100644 > --- a/net/sctp/socket.c > +++ b/net/sctp/socket.c > @@ -6411,6 +6411,35 @@ static int sctp_getsockopt_local_addrs(struct sock *sk, int len, > return err; > } > > +static int __sctp_sock_get_primary_addr(struct sock *sk, struct sctp_prim *prim) > +{ > + struct sctp_association *asoc; > + > + asoc = sctp_id2assoc(sk, prim->ssp_assoc_id); > + if (!asoc) > + return -EINVAL; > + if (!asoc->peer.primary_path) > + return -ENOTCONN; > + > + memcpy(&prim->ssp_addr, &asoc->peer.primary_path->ipaddr, > + asoc->peer.primary_path->af_specific->sockaddr_len); > + > + sctp_get_pf_specific(sk->sk_family)->addr_to_user(sctp_sk(sk), > + (union sctp_addr *)&prim->ssp_addr); > + return 0; > +} > + > +int sctp_sock_get_primary_addr(struct sock *sk, struct sctp_prim *prim) > +{ > + int ret; > + > + lock_sock(sk); > + ret = __sctp_sock_get_primary_addr(sk, prim); > + release_sock(sk); > + return ret; > +} > +EXPORT_SYMBOL(sctp_sock_get_primary_addr); > + > /* 7.1.10 Set Primary Address (SCTP_PRIMARY_ADDR) > * > * Requests that the local SCTP stack use the enclosed peer address as > @@ -6421,35 +6450,19 @@ static int sctp_getsockopt_primary_addr(struct sock *sk, int len, > char __user *optval, int __user *optlen) > { > struct sctp_prim prim; > - struct sctp_association *asoc; > - struct sctp_sock *sp = sctp_sk(sk); > + int ret; > > if (len < sizeof(struct sctp_prim)) > return -EINVAL; > - > - len = sizeof(struct sctp_prim); > - > - if (copy_from_user(&prim, optval, len)) > + if (copy_from_user(&prim, optval, sizeof(struct sctp_prim))) > return -EFAULT; > > - asoc = sctp_id2assoc(sk, prim.ssp_assoc_id); > - if (!asoc) > - return -EINVAL; > - > - if (!asoc->peer.primary_path) > - return -ENOTCONN; > - > - memcpy(&prim.ssp_addr, &asoc->peer.primary_path->ipaddr, > - asoc->peer.primary_path->af_specific->sockaddr_len); > - > - sctp_get_pf_specific(sk->sk_family)->addr_to_user(sp, > - (union sctp_addr *)&prim.ssp_addr); > + ret = __sctp_sock_get_primary_addr(sk, &prim); > + if (ret) > + return ret; > > - if (put_user(len, optlen)) > + if (put_user(len, optlen) || copy_to_user(optval, &prim, len)) > return -EFAULT; > - if (copy_to_user(optval, &prim, len)) > - return -EFAULT; > - > return 0; > } > > -- > 2.26.2 >
David Laight
2020-May-14 09:51 UTC
[Ocfs2-devel] [PATCH 32/33] sctp: add sctp_sock_get_primary_addr
From: Marcelo Ricardo Leitner> Sent: 13 May 2020 19:03 > > On Wed, May 13, 2020 at 08:26:47AM +0200, Christoph Hellwig wrote: > > Add a helper to directly get the SCTP_PRIMARY_ADDR sockopt from kernel > > space without going through a fake uaccess. > > Same comment as on the other dlm/sctp patch.Wouldn't it be best to write sctp_[gs]etsockotp() that use a kernel buffer and then implement the user-space calls using a wrapper that does the copies to an on-stack (or malloced if big) buffer. That will also simplify the code be removing all the copies and -EFAULT returns. Only the size checks will be needed and the code can assume the buffer is at least the size of the on-stack buffer. Our SCTP code uses SO_REUSADDR, SCTP_EVENTS, SCTP_NODELAY, SCTP_STATUS, SCTP_INITMSG, IPV6_ONLY, SCTP_SOCKOPT_BINDX_ADD and SO_LINGER. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)