musl/src/network/sendmsg.c

#include <sys/socket.h>
#include <limits.h>
#include "syscall.h"
#include "libc.h"

ssize_t sendmsg(int fd, const struct msghdr *msg, int flags)
{
	ssize_t r;
#if LONG_MAX > INT_MAX
	struct msghdr h;
	if (msg) {
		h = *msg;
		h.__pad1 = h.__pad2 = 0;
		msg = &h;
	}
#endif
	CANCELPT_BEGIN;
	r = socketcall(sendmsg, fd, msg, flags, 0, 0, 0);
	CANCELPT_END;
	return r;
}
initial check-in, version 0.5.0 15 years ago			`#include <sys/socket.h>`
workaround broken msghdr struct on 64bit linux POSIX clearly specifies the type of msg_iovlen and msg_controllen, and Linux ignores it and makes them both size_t instead. to work around this we add padding (instead of just using the wrong types like glibc does), but we also need to patch-up the struct before passing it to the kernel in case the caller did not zero-fill it. if i could trust the kernel to just ignore the upper 32 bits, this would not be necessary, but i don't think it will ignore them... 15 years ago			`#include <limits.h>`
initial check-in, version 0.5.0 15 years ago			`#include "syscall.h"`
			`#include "libc.h"`

			`ssize_t sendmsg(int fd, const struct msghdr *msg, int flags)`
			`{`
			`ssize_t r;`
workaround broken msghdr struct on 64bit linux POSIX clearly specifies the type of msg_iovlen and msg_controllen, and Linux ignores it and makes them both size_t instead. to work around this we add padding (instead of just using the wrong types like glibc does), but we also need to patch-up the struct before passing it to the kernel in case the caller did not zero-fill it. if i could trust the kernel to just ignore the upper 32 bits, this would not be necessary, but i don't think it will ignore them... 15 years ago			`#if LONG_MAX > INT_MAX`
			`struct msghdr h;`
			`if (msg) {`
			`h = *msg;`
			`h.__pad1 = h.__pad2 = 0;`
			`msg = &h;`
			`}`
			`#endif`
initial check-in, version 0.5.0 15 years ago			`CANCELPT_BEGIN;`
cleanup socketcall syscall interface to ease porting to sane(r) archs 15 years ago			`r = socketcall(sendmsg, fd, msg, flags, 0, 0, 0);`
initial check-in, version 0.5.0 15 years ago			`CANCELPT_END;`
			`return r;`
			`}`