diff options
Diffstat (limited to 'lib/libc/sys/recv.2')
| -rw-r--r-- | lib/libc/sys/recv.2 | 55 |
1 files changed, 4 insertions, 51 deletions
diff --git a/lib/libc/sys/recv.2 b/lib/libc/sys/recv.2 index 4867ea7..36a8a9d 100644 --- a/lib/libc/sys/recv.2 +++ b/lib/libc/sys/recv.2 @@ -28,7 +28,7 @@ .\" @(#)recv.2 8.3 (Berkeley) 2/21/94 .\" $FreeBSD$ .\" -.Dd January 29, 2016 +.Dd February 3, 2017 .Dt RECV 2 .Os .Sh NAME @@ -267,57 +267,10 @@ with no data buffer provided immediately after an .Fn accept system call. .Pp -Open file descriptors are now passed as ancillary data for +With .Dv AF_UNIX -domain sockets, with -.Fa cmsg_level -set to -.Dv SOL_SOCKET -and -.Fa cmsg_type -set to -.Dv SCM_RIGHTS . -The close-on-exec flag on received descriptors is set according to the -.Dv MSG_CMSG_CLOEXEC -flag passed to -.Fn recvmsg . -.Pp -Process credentials can also be passed as ancillary data for -.Dv AF_UNIX -domain sockets using a -.Fa cmsg_type -of -.Dv SCM_CREDS . -In this case, -.Fa cmsg_data -should be a structure of type -.Fa cmsgcred , -which is defined in -.In sys/socket.h -as follows: -.Bd -literal -struct cmsgcred { - pid_t cmcred_pid; /* PID of sending process */ - uid_t cmcred_uid; /* real UID of sending process */ - uid_t cmcred_euid; /* effective UID of sending process */ - gid_t cmcred_gid; /* real GID of sending process */ - short cmcred_ngroups; /* number or groups */ - gid_t cmcred_groups[CMGROUP_MAX]; /* groups */ -}; -.Ed -.Pp -If a sender supplies ancillary data with enough space for the above struct -tagged as -.Dv SCM_CREDS -control message type to the -.Fn sendmsg -system call, then kernel will fill in the credential information of the -sending process and deliver it to the receiver. -Since receiver usually has no control over a sender, this method of retrieving -credential information isn't reliable. -For reliable retrieval of remote side credentials it is advised to use the -.Dv LOCAL_CREDS -socket option on the receiving socket. +domain sockets, ancillary data can be used to pass file descriptors and +process credentials. See .Xr unix 4 for details. |
