mtcp_ppeek - Peek into the bytestream from a monitoring socket from a given offset #include <mos_api.h> "ssize_t mtcp_ppeek(mctx_t " mctx ", int " sockid ", int " side ", char *" buf ", size_t " len ", uint64_t " off ); mtcp_ppeek () can be used to peek up to "len" number of bytes from a monitoring socket via socket descriptor "sockid" into the buffer starting at "buf." from "off"; value which is the offset distance (in bytes) from the TCP initial sequence number. It is the responsibility of the user to allocate memory for "buf" array. For cases when the total number of buffered unread bytes in the socket are less than "len," "mtcp_ppeek()" copies entire data to "buf" and returns the actual number of bytes that can be used by the application. Note that the "off" can also point to the data in the fragmented buffer list of the TCP ring buffer (see mtcp_getsockopt()). If there is no received byte at "off" in the TCP ring buffer, it returns error. If there are received bytes starting from "off", len is set to be the number of bytes read from the buffer. After mtcp_ppeek(), the data in the TCP ring buffer will not be flushed, and the monitor offset used by mtcp_peek() is not changed. An mtcp_ppeek () call takes two additional argument named "mctx", that represents the per-core mTCP context in an application (see mtcp_create_context() for details); and "side" that informs the stack whether it needs to peek the client (MOS_SIDE_CLI) or server (MOS_SIDE_SVR) side. """""""""""""""""""""""""""""""""""""""""""""""""""""""""""
On success, the number of bytes read is returned. It is not an error if this number is smaller than the number of bytes requested; this may happen when the socket has fewer number of bytes buffered at that moment. On all errors, -1 is returned and "errno" is set appropriately. """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""

18 "EACCES" The "mctx" argument is invalid.

18 "EBADF" The socket descriptor "sockid" is invalid.

18 "EINVAL" The buffer management of the monitoring socket with "sockid" was already disabled.

18 "ESOCKTNOSUPPORT" The socket referred to by "sockid" has invalid "type"

18 "ENOTCONN" Th socket referred to by "sockid" is in a TCP state that disallows read operations.

18 "ENODATA" The socket referred to by "sockid" does not have any available bytes in its buffer for reading.

18 "EPERM" The caller is not permitted to access this function. """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
"""".SH CONFORMING TO
""""POSIX.1-2001.
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mOS development team <[email protected]> """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
mtcp_peek (), mtcp_socket (), """""""""""""""""""""""""""""""""""""""""""""""""""""
This page is part of mOS release 0.3 "docs" section. A description of the project, and information about reporting bugs, can be found at \%http://mos.kaist.edu/. """""""""""""""""""""""""""""""""""""""""""""""""""""