| Message ID | 20230913152744.2333228-7-leitao@debian.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | io_uring: Initial support for {s,g}etsockopt commands | expand |
On 9/13/23 9:27 AM, Breno Leitao wrote: > Add support for getsockopt command (SOCKET_URING_OP_GETSOCKOPT), where > level is SOL_SOCKET. This is similar to the getsockopt(2) system > call, and both parameters are pointers to userspace. > > Important to say that userspace needs to keep the pointer alive until > the CQE is completed. Since it's holding the data needed, this is true for any request that is writing data. IOW, this is not unusual and should be taken for granted. I think this may warrant a bit of rewording if the patch is respun, if not then just ignore it. > diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c > index 5753c3611b74..a2a6ac0c503b 100644 > --- a/io_uring/uring_cmd.c > +++ b/io_uring/uring_cmd.c > @@ -167,6 +167,19 @@ int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw, > } > EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed); > > +static inline int io_uring_cmd_getsockopt(struct socket *sock, > + struct io_uring_cmd *cmd, > + unsigned int issue_flags) > +{ > + void __user *optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval)); > + int __user *optlen = u64_to_user_ptr(READ_ONCE(cmd->sqe->optlen)); > + bool compat = !!(issue_flags & IO_URING_F_COMPAT); > + int optname = READ_ONCE(cmd->sqe->optname); > + int level = READ_ONCE(cmd->sqe->level); > + > + return do_sock_getsockopt(sock, compat, level, optname, optval, optlen); > +} Personal preference, but any other io_uring generally uses the format of: bool compat = !!(issue_flags & IO_URING_F_COMPAT); void __user *optval; int __user *optlen; int optname, level; optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval)); optlen = u64_to_user_ptr(READ_ONCE(cmd->sqe->optlen)); optname = READ_ONCE(cmd->sqe->optname); level = READ_ONCE(cmd->sqe->level); return do_sock_getsockopt(sock, compat, level, optname, optval, optlen); which I find a lot easier to read than bundling variable declarations and reading the values into them. And I always forget that cmd->sqe is a copy for URING_CMD, which makes this just look wrong as they should've been read at prep time rather than issue time. But it's fine!
On 9/13/23 1:36 PM, Jens Axboe wrote: > On 9/13/23 9:27 AM, Breno Leitao wrote: >> Add support for getsockopt command (SOCKET_URING_OP_GETSOCKOPT), where >> level is SOL_SOCKET. This is similar to the getsockopt(2) system >> call, and both parameters are pointers to userspace. >> >> Important to say that userspace needs to keep the pointer alive until >> the CQE is completed. > > Since it's holding the data needed, this is true for any request that > is writing data. IOW, this is not unusual and should be taken for > granted. I think this may warrant a bit of rewording if the patch is > respun, if not then just ignore it. reads data of course, writing into the userspace buffer.
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 8e61f8b7c2ce..1c789ee6462d 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -43,6 +43,10 @@ struct io_uring_sqe { union { __u64 addr; /* pointer to buffer or iovecs */ __u64 splice_off_in; + struct { + __u32 level; + __u32 optname; + }; }; __u32 len; /* buffer size or number of iovecs */ union { @@ -89,6 +93,10 @@ struct io_uring_sqe { __u64 addr3; __u64 __pad2[1]; }; + struct { + __u64 optval; + __u64 optlen; + }; /* * If the ring is initialized with IORING_SETUP_SQE128, then * this field is used for 80 bytes of arbitrary command data @@ -734,6 +742,7 @@ struct io_uring_recvmsg_out { enum { SOCKET_URING_OP_SIOCINQ = 0, SOCKET_URING_OP_SIOCOUTQ, + SOCKET_URING_OP_GETSOCKOPT, }; #ifdef __cplusplus diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c index 5753c3611b74..a2a6ac0c503b 100644 --- a/io_uring/uring_cmd.c +++ b/io_uring/uring_cmd.c @@ -167,6 +167,19 @@ int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw, } EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed); +static inline int io_uring_cmd_getsockopt(struct socket *sock, + struct io_uring_cmd *cmd, + unsigned int issue_flags) +{ + void __user *optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval)); + int __user *optlen = u64_to_user_ptr(READ_ONCE(cmd->sqe->optlen)); + bool compat = !!(issue_flags & IO_URING_F_COMPAT); + int optname = READ_ONCE(cmd->sqe->optname); + int level = READ_ONCE(cmd->sqe->level); + + return do_sock_getsockopt(sock, compat, level, optname, optval, optlen); +} + #if defined(CONFIG_NET) int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags) { @@ -189,6 +202,8 @@ int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags) if (ret) return ret; return arg; + case SOCKET_URING_OP_GETSOCKOPT: + return io_uring_cmd_getsockopt(sock, cmd, issue_flags); default: return -EOPNOTSUPP; }