| Message ID | 20230817145554.892543-7-leitao@debian.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | io_uring: Initial support for {s,g}etsockopt commands | expand |
Breno Leitao <leitao@debian.org> writes: > +#if defined(CONFIG_NET) > int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags) > { > struct socket *sock = cmd->file->private_data; > @@ -189,8 +219,16 @@ 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; > } > } > +#else > +int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags) > +{ > + return -EOPNOTSUPP; > +} > +#endif > EXPORT_SYMBOL_GPL(io_uring_cmd_sock); The CONFIG_NET guards are unrelated and need to go in a separate commit. Specially because it is not only gating getsockopt, but also the already merged SOCKET_URING_OP_SIOCINQ/_OP_SIOCOUTQ.
Hello Gabriel, On Thu, Aug 17, 2023 at 02:38:46PM -0400, Gabriel Krisman Bertazi wrote: > Breno Leitao <leitao@debian.org> writes: > > > +#if defined(CONFIG_NET) > > int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags) > > { > > struct socket *sock = cmd->file->private_data; > > @@ -189,8 +219,16 @@ 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; > > } > > } > > +#else > > +int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags) > > +{ > > + return -EOPNOTSUPP; > > +} > > +#endif > > EXPORT_SYMBOL_GPL(io_uring_cmd_sock); > > The CONFIG_NET guards are unrelated and need to go in a separate commit. > Specially because it is not only gating getsockopt, but also the already > merged SOCKET_URING_OP_SIOCINQ/_OP_SIOCOUTQ. Well, so far, if CONFIG_NET is disable, and you call io_uring_cmd_getsockopt, the callbacks will be called and returned -EOPNOTSUPP. With this new patch, it will eventually call sk_getsockopt which does not exist in the CONFIG_NET=n world. That is why I have this protection now. I.e, this `#if defined(CONFIG_NET)` is only necessary now, since it is the first time this function (io_uring_cmd_sock) will call a function that does not exist if CONFIG_NET is disabled. I can split it in a different patch, if you think it makes a difference.
Breno Leitao <leitao@debian.org> writes: > Hello Gabriel, > > On Thu, Aug 17, 2023 at 02:38:46PM -0400, Gabriel Krisman Bertazi wrote: >> Breno Leitao <leitao@debian.org> writes: >> >> > +#if defined(CONFIG_NET) >> > int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags) >> > { >> > struct socket *sock = cmd->file->private_data; >> > @@ -189,8 +219,16 @@ 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; >> > } >> > } >> > +#else >> > +int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags) >> > +{ >> > + return -EOPNOTSUPP; >> > +} >> > +#endif >> > EXPORT_SYMBOL_GPL(io_uring_cmd_sock); >> >> The CONFIG_NET guards are unrelated and need to go in a separate commit. >> Specially because it is not only gating getsockopt, but also the already >> merged SOCKET_URING_OP_SIOCINQ/_OP_SIOCOUTQ. > > Well, so far, if CONFIG_NET is disable, and you call > io_uring_cmd_getsockopt, the callbacks will be called and returned > -EOPNOTSUPP. I'm not talking about io_uring_cmd_getsockopt; that would obviously return -EOPNOTSUPP before as well. But you are changing io_uring_cmd_sock, which does more things: int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags) { [...] if (!prot || !prot->ioctl) return -EOPNOTSUPP; switch (cmd->sqe->cmd_op) { case SOCKET_URING_OP_SIOCINQ: ret = prot->ioctl(sk, SIOCINQ, &arg); if (ret) return ret; return arg; case SOCKET_URING_OP_SIOCOUTQ: ret = prot->ioctl(sk, SIOCOUTQ, &arg); if (ret) return ret; With your patch, these two cmd_op, are now being gated by CONFIG_NET. I think it makes sense for them to be gated by it, But it should be in a separated change, or at least explained in your commit message. > With this new patch, it will eventually call sk_getsockopt which does > not exist in the CONFIG_NET=n world. That is why I have this > protection now. I.e, this `#if defined(CONFIG_NET)` is only necessary now, > since it is the first time this function (io_uring_cmd_sock) will call a > function that does not exist if CONFIG_NET is disabled. > > I can split it in a different patch, if you think it makes a difference.
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 9fc7195f25df..8152151080db 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 { @@ -79,6 +83,7 @@ struct io_uring_sqe { union { __s32 splice_fd_in; __u32 file_index; + __u32 optlen; struct { __u16 addr_len; __u16 __pad3[1]; @@ -89,6 +94,7 @@ struct io_uring_sqe { __u64 addr3; __u64 __pad2[1]; }; + __u64 optval; /* * If the ring is initialized with IORING_SETUP_SQE128, then * this field is used for 80 bytes of arbitrary command data @@ -729,6 +735,7 @@ 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 5f32083bd0a5..7b768f1bf4df 100644 --- a/io_uring/uring_cmd.c +++ b/io_uring/uring_cmd.c @@ -168,6 +168,36 @@ int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw, } EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed); +INDIRECT_CALLABLE_DECLARE(bool tcp_bpf_bypass_getsockopt(int level, + int optname)); +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 optname = READ_ONCE(cmd->sqe->optname); + int optlen = READ_ONCE(cmd->sqe->optlen); + int level = READ_ONCE(cmd->sqe->level); + int err; + + err = security_socket_getsockopt(sock, level, optname); + if (err) + return err; + + if (level == SOL_SOCKET) { + err = sk_getsockopt(sock->sk, level, optname, + USER_SOCKPTR(optval), + KERNEL_SOCKPTR(&optlen)); + if (err) + return err; + + return optlen; + } + + return -EOPNOTSUPP; +} + +#if defined(CONFIG_NET) int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags) { struct socket *sock = cmd->file->private_data; @@ -189,8 +219,16 @@ 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; } } +#else +int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags) +{ + return -EOPNOTSUPP; +} +#endif EXPORT_SYMBOL_GPL(io_uring_cmd_sock);
Add support for getsockopt command (SOCKET_URING_OP_GETSOCKOPT), where level is SOL_SOCKET. This is leveraging the sockptr_t infrastructure, where a sockptr_t is either userspace or kernel space, and handled as such. Function io_uring_cmd_getsockopt() is inspired by __sys_getsockopt(). Differently from the getsockopt(2), the optlen field is not a userspace pointers. In getsockopt(2), userspace provides optlen pointer, which is overwritten by the kernel. In this implementation, userspace passes a u32, and the new value is returned in cqe->res. I.e., optlen is not a pointer. Important to say that userspace needs to keep the pointer alive until the CQE is completed. Signed-off-by: Breno Leitao <leitao@debian.org> --- include/uapi/linux/io_uring.h | 7 +++++++ io_uring/uring_cmd.c | 38 +++++++++++++++++++++++++++++++++++ 2 files changed, 45 insertions(+)