// nvkmstrace.c - LD_PRELOAD shim: log NVKMS_IOCTL_IOWR commands
#define _GNU_SOURCE
#include <stdio.h>
#include <stdarg.h>
#include <stdint.h>
#include <string.h>
#include <dlfcn.h>
#include <sys/ioctl.h>

struct nvkms_ioctl_params {
	uint32_t cmd;
	uint32_t size;
	uint64_t address;
};

#define NVKMS_REQ 0xC0106D00UL

static int (*real_ioctl)(int, unsigned long, ...);

int ioctl(int fd, unsigned long req, ...)
{
	va_list ap;
	void *arg;

	va_start(ap, req);
	arg = va_arg(ap, void *);
	va_end(ap);
	if (!real_ioctl)
		real_ioctl = dlsym(RTLD_NEXT, "ioctl");
	if (req == NVKMS_REQ && arg) {
		struct nvkms_ioctl_params *p = arg;
		int rc;

		rc = real_ioctl(fd, req, arg);
		fprintf(stderr, "NVKMS_IOCTL cmd=%u size=%u addr=%p rc=%d\n",
			p->cmd, p->size, (void *)(uintptr_t)p->address, rc);
		if (p->address && p->size) {
			unsigned char *q = (unsigned char *)(uintptr_t)p->address;
			unsigned n = p->size < 64 ? p->size : 64, i;

			fprintf(stderr, "  data:");
			for (i = 0; i < n; i++)
				fprintf(stderr, " %02x", q[i]);
			fprintf(stderr, "\n");
			if (p->size >= 700) {
				/* reply.status candidates: request = 32 + 4 +
				 * 4*1 (NvBool=NvU8) + 16*(32+4) = 616 bytes */
				unsigned o;

				for (o = 600; o <= 700; o += 4) {
					unsigned v;
					memcpy(&v, q + o, 4);
					if (v <= 16)
						fprintf(stderr, "  small@%u=%u\n",
							o, v);
				}
			}
		}
		return rc;
	}
	return real_ioctl(fd, req, arg);
}