/* kvm.cc: provides support for OpenBSD's libkvm
**
** Theoretically, this code *should* work, but I haven't
** even tested it.
**
** This also contains some code to support NetBSD, although
** it calls the kernel instead of kvm.
*/

#include "animia/fd/kvm.h"
#include "animia/fd.h"
#include "animia.h"

#include <sys/types.h>
#include <sys/user.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/param.h>
#include <sys/vnode.h>
#include <sys/queue.h>
#include <sys/sysctl.h>

#include <kvm.h>

#include <string>

namespace animia::internal::kvm {

bool EnumerateOpenProcesses(process_proc_t process_proc) {
	char errbuf[_POSIX2_LINE_MAX];
	kvm_t* kernel = kvm_openfiles(NULL, NULL, NULL, O_RDONLY, errbuf);
	if (!kernel)
		return false;

	int entries = 0;
	struct kinfo_proc* kinfo = kvm_getprocs(kernel, KERN_PROC_ALL, 0, &entries);
	if (!kinfo)
		return false;

	for (int i = 0; i < entries; i++)
		if (!process_proc({kinfo[i].ki_paddr->p_pid, kinfo[i].ki_paddr->p_comm}))
			return false;

	kvm_close(kernel);

	return true;
}

bool EnumerateOpenFiles(std::set<pid_t>& pids, open_file_proc_t open_file_proc) {
#ifdef HAVE_KVM_GETFILES
	char errbuf[_POSIX2_LINE_MAX];
	kvm_t* kernel = kvm_openfiles(NULL, NULL, NULL, O_RDONLY, errbuf);
	if (!kernel)
		return false;

	for (const auto& pid : pids) {
		int cnt;
		struct kinfo_file* kfile = kvm_getfiles(kernel, KERN_FILE_BYPID, pid, &cnt);
		if (!kfile)
			return false;

		for (int i = 0; i < cnt; i++)
			if (!open_file_proc({pid, kfile[i].kf_path}))
				return false;
	}

	kvm_close(kernel);

	return true;
#else /* For NetBSD... I think */
	for (const auto& pid : pids) {
		int mib[6] = {
			CTL_KERN,
			KERN_FILE2,
			KERN_FILE_BYPID,
			pid,
			sizeof(struct kinfo_file),
			0
		};

		size_t len = 0;
		if (sysctl(mib, sizeof(mib)/sizeof(mib[0]), NULL, &len, NULL, 0) == -1)
			return false;

		mib[5] = len / sizeof(struct kinfo_file);

		std::unique_ptr<struct kinfo_file[]> buf(new struct kinfo_file[mib[5]]);
		if (!buf)
			return false;

		if (sysctl(mib, sizeof(mib)/sizeof(mib[0]), buf.get(), &len, NULL, 0) == -1)
			return false;

		for (size_t i = 0; i < cnt; i++)
			if (!open_file_proc({pid, kfile[i].kf_path}))
				return false;
	}

	return true;
#endif
}

}