It expects a "struct sockaddr_in", not a string! Therefore it doesn't understand your address. It also expects a port number to connect to, not just an IP address.
We need to add our remote office to our linux routing table.
Our internal office ip addresses are all in the range of 198.9.200.x
with an subnet mask of 255.255.255.0
the remote office has ip addresses in the range of 192.168.0.0 and also a subnet mask of 255.255.255.0
when i use the... (3 Replies)
I not able to ping outside the internet. i am able to ping my 192. ip address. when i try to ping a 68. ip address i get no route to host. what should i do to correct this issue. I have sco openserver 5.05 (6 Replies)
hello,
I am doing Socket programming..
when I am establishing a socket connection using TCP protocol ...I am getting
Error :: No route to host. at the client side during connect() call...........that it is returning -1.
So I thing problem lies here......but what to do now...
So for just... (6 Replies)
Hi,
I was porting ipv4 application to ipv6; i was done with TCP transports. Now i am facing problem with SCTp transport at runtime.
To test SCTP transport I am using following server and client socket programs. Server program runs fine, but client program fails giving Invalid Arguments for... (0 Replies)
I get below error when using telnet and ssh ??
Why ? the ip address of linux server is 10.155.25.22 =tstgcota ??
# netstat -rn
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
192.168.75.0 0.0.0.0 255.255.255.0 U 0 0... (6 Replies)
Hi,
I have a system with network interfaces en0 and en1
en0:
physical ip: 1.1.1.10
virtual ip1: 192.168.100.11
virtual ip2: 192.168.100.12
en1:
physical ip: 1.1.1.20
virtual ip1: 192.168.100.20
virtual ip2: 192.168.100.21
default gateway ist 192.168.100.254
when I open a... (12 Replies)
I need clarification on whether it is okay to set socket options on a listening socket
simultaneously when it is being used in an accept() call?
Following is the scenario:-
-- Task 1 - is executing in a loop - polling a listen socket, lets call it 'fd', (whose file descriptor is global)... (2 Replies)
I have a unix machine that operates some CNC machines, I need to hook up my windows machine through core ftp to load programs onto the box.
The card i need to route to for the FTP on unix is tu1
I need to check the routing tables on the unix box to see which IP address will automatically... (2 Replies)
A linux box is supposed to emailing the results of backups to the windows exchange server, but nothing arrives. it never has, as the muppet who set up the Windows domain knew nothing about linux. I know only slightly more than that...
pretty sure sendmail is the daemon running to handle mail. it... (0 Replies)
Hi,
I have installed RHEL4 using vmware workstation..
Host OS: Windows XP
Guest OS: RHEL4
Pls refer step 17 & 18 in below link...
ORACLE-BASE - Red Hat Enterprise Linux 4 and Centos 4 Installation
1) If i choose to assign IP automatically (using DHCP) means, i am able to connect RHEL4... (3 Replies)
Discussion started by: thomasraj87
3 Replies
LEARN ABOUT PLAN9
sendmmsg
SENDMMSG(2) Linux Programmer's Manual SENDMMSG(2)NAME
sendmmsg - send multiple messages on a socket
SYNOPSIS
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <sys/socket.h>
int sendmmsg(int sockfd, struct mmsghdr *msgvec, unsigned int vlen,
int flags);
DESCRIPTION
The sendmmsg() system call is an extension of sendmsg(2) that allows the caller to transmit multiple messages on a socket using a single
system call. (This has performance benefits for some applications.)
The sockfd argument is the file descriptor of the socket on which data is to be transmitted.
The msgvec argument is a pointer to an array of mmsghdr structures. The size of this array is specified in vlen.
The mmsghdr structure is defined in <sys/socket.h> as:
struct mmsghdr {
struct msghdr msg_hdr; /* Message header */
unsigned int msg_len; /* Number of bytes transmitted */
};
The msg_hdr field is a msghdr structure, as described in sendmsg(2). The msg_len field is used to return the number of bytes sent from the
message in msg_hdr (i.e., the same as the return value from a single sendmsg(2) call).
The flags argument contains flags ORed together. The flags are the same as for sendmsg(2).
A blocking sendmmsg() call blocks until vlen messages have been sent. A nonblocking call sends as many messages as possible (up to the
limit specified by vlen) and returns immediately.
On return from sendmmsg(), the msg_len fields of successive elements of msgvec are updated to contain the number of bytes transmitted from
the corresponding msg_hdr. The return value of the call indicates the number of elements of msgvec that have been updated.
RETURN VALUE
On success, sendmmsg() returns the number of messages sent from msgvec; if this is less than vlen, the caller can retry with a further
sendmmsg() call to send the remaining messages.
On error, -1 is returned, and errno is set to indicate the error.
ERRORS
Errors are as for sendmsg(2). An error is returned only if no datagrams could be sent. See also BUGS.
VERSIONS
The sendmmsg() system call was added in Linux 3.0. Support in glibc was added in version 2.14.
CONFORMING TO
sendmmsg() is Linux-specific.
NOTES
The value specified in vlen is capped to UIO_MAXIOV(1024).
BUGS
If an error occurs after at least one message has been sent, the call succeeds, and returns the number of messages sent. The error code is
lost. The caller can retry the transmission, starting at the first failed message, but there is no guarantee that, if an error is
returned, it will be the same as the one that was lost on the previous call.
EXAMPLE
The example below uses sendmmsg() to send onetwo and three in two distinct UDP datagrams using one system call. The contents of the first
datagram originates from a pair of buffers.
#define _GNU_SOURCE
#include <netinet/ip.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
int
main(void)
{
int sockfd;
struct sockaddr_in addr;
struct mmsghdr msg[2];
struct iovec msg1[2], msg2;
int retval;
sockfd = socket(AF_INET, SOCK_DGRAM, 0);
if (sockfd == -1) {
perror("socket()");
exit(EXIT_FAILURE);
}
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
addr.sin_port = htons(1234);
if (connect(sockfd, (struct sockaddr *) &addr, sizeof(addr)) == -1) {
perror("connect()");
exit(EXIT_FAILURE);
}
memset(msg1, 0, sizeof(msg1));
msg1[0].iov_base = "one";
msg1[0].iov_len = 3;
msg1[1].iov_base = "two";
msg1[1].iov_len = 3;
memset(&msg2, 0, sizeof(msg2));
msg2.iov_base = "three";
msg2.iov_len = 5;
memset(msg, 0, sizeof(msg));
msg[0].msg_hdr.msg_iov = msg1;
msg[0].msg_hdr.msg_iovlen = 2;
msg[1].msg_hdr.msg_iov = &msg2;
msg[1].msg_hdr.msg_iovlen = 1;
retval = sendmmsg(sockfd, msg, 2, 0);
if (retval == -1)
perror("sendmmsg()");
else
printf("%d messages sent
", retval);
exit(0);
}
SEE ALSO recvmmsg(2), sendmsg(2), socket(2), socket(7)COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the
latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.
Linux 2018-02-02 SENDMMSG(2)