|
HTML rendering created 2026-05-24 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|
|
NAME | LIBRARY | SYNOPSIS | DESCRIPTION | ERRORS | STANDARDS | HISTORY | SEE ALSO | COLOPHON |
|
|
|
IP_RECVERR(2const) IP_RECVERR(2const)
IP_RECVERR - extended reliable error message passing
Standard C library (libc, -lc)
#include <netinet/in.h> /* Definition of IP* constants */
#include <sys/socket.h>
int setsockopt(int sockfd, IPPROTO_IP, IP_RECVERR,
const int *enable, sizeof(int));
int getsockopt(int sockfd, IPPROTO_IP, IP_RECVERR,
int *enabled, sizeof(int));
struct sock_extended_err {
uint32_t ee_errno; /* error number */
uint8_t ee_origin; /* where the error originated */
uint8_t ee_type; /* type */
uint8_t ee_code; /* code */
uint8_t ee_pad;
uint32_t ee_info; /* additional information */
uint32_t ee_data; /* other data */
/* More data may follow */
};
#define SO_EE_ORIGIN_NONE 0
#define SO_EE_ORIGIN_LOCAL 1
#define SO_EE_ORIGIN_ICMP 2
#define SO_EE_ORIGIN_ICMP6 3
struct sockaddr *SO_EE_OFFENDER(struct sock_extended_err *);
Enable extended reliable error message passing (default:
disabled).
When enabled on a datagram socket, all generated errors will be
queued in a per-socket error queue. When the user receives an
error from a socket operation, the errors can be received by
calling recvmsg(2) with the MSG_ERRQUEUE flag set. The
sock_extended_err structure describing the error will be passed in
an ancillary message with the type IP_RECVERR and the level
IPPROTO_IP. This is useful for reliable error handling on
unconnected sockets. The received data portion of the error queue
contains the error packet.
The IP_RECVERR control message contains a sock_extended_err
structure.
.ee_errno
contains the errno number of the queued error.
.ee_origin
is the origin code of where the error originated.
The other fields are protocol-specific.
The macro SO_EE_OFFENDER() returns a pointer to the address of the
network object where the error originated from given a pointer to
the ancillary message. If this address is not known, the
.sa_family member of the sockaddr contains AF_UNSPEC and the other
fields of the sockaddr are undefined.
IP uses the sock_extended_err structure as follows:
• .ee_origin is set to SO_EE_ORIGIN_ICMP for errors received as
an ICMP packet, or SO_EE_ORIGIN_LOCAL for locally generated
errors. Unknown values should be ignored.
• .ee_type and .ee_code are set from the type and code fields of
the ICMP header.
• .ee_info contains the discovered MTU for EMSGSIZE errors.
• The message also contains the sockaddr_in of the node caused
that the error, which can be accessed with the SO_EE_OFFENDER()
macro.
The .sin_family field of the SO_EE_OFFENDER() address is AF_UNSPEC
when the source was unknown. When the error originated from the
network, all IP options (IP_OPTIONS(2const), IP_TTL(2const), etc.)
enabled on the socket and contained in the error packet are passed
as control messages. The payload of the packet causing the error
is returned as normal payload.
TCP has no error queue; MSG_ERRQUEUE is not permitted on
SOCK_STREAM sockets. IP_RECVERR is valid for TCP, but all errors
are returned by socket function return or SO_ERROR only.
For raw sockets, IP_RECVERR enables passing of all received ICMP
errors to the application, otherwise errors are reported only on
connected sockets
See IPPROTO_IP(2const). See setsockopt(2). See ip(7).
Linux.
Linux 2.2.
IPPROTO_IP(2const), setsockopt(2), ip(7)
This page is part of the man-pages (Linux kernel and C library
user-space interface documentation) project. Information about
the project can be found at
⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report
for this manual page, see
⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
This page was obtained from the tarball man-pages-6.18.tar.gz
fetched from
⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
2026-05-24. If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-
to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to
man-pages@man7.org
Linux man-pages 6.18 2025-11-25 IP_RECVERR(2const)
Pages that refer to this page: IP_MTU_DISCOVER(2const), IPPROTO_IP(2const), IPV6_RECVERR(2const)
|
HTML rendering created 2026-05-24 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|