#define _GNU_SOURCE

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "libldetect.h"
#include "libldetect-private.h"
#include "common.h"

typedef struct {
	FILE *f;
	pid_t pid;
} fh;

static fh fh_open(char *fname) {
	fh ret;
	int length = strlen(fname);

	if (access(fname, R_OK) == 0) {
		ret.f = fopen(fname, "r");
		ret.pid = 0;
	} else {
		int fdno[2];
		char *fname_gz = alloca(length + sizeof(".gz"));
		sprintf(fname_gz, "%s.gz", fname);
		if (access(fname_gz, R_OK) != 0) {
			fprintf(stderr, "Missing pciusbtable (should be %s)\n", fname);
			exit(1);
		}
		if (pipe(fdno)) {
			perror("pciusb");
			exit(1);
		}

		if ((ret.pid = fork()) != 0) {
			ret.f = fdopen(fdno[0], "r");
			close(fdno[1]);
		} else {
			char* cmd[5];
			int ip = 0;
			char *ld_loader = getenv("LD_LOADER");

			if (ld_loader && *ld_loader)
				cmd[ip++] = ld_loader;

			cmd[ip++] = "gzip";
			cmd[ip++] = "-cd";
			cmd[ip++] = fname_gz;
			cmd[ip++] = NULL;

			dup2(fdno[1], STDOUT_FILENO);
			close(fdno[0]);
			close(fdno[1]);
			execvp(cmd[0], cmd);
			perror("pciusb"); 
			exit(2);
		}
	}
	return ret;
}

static void fh_close(fh *f) {
	fclose(f->f);
	if (f->pid > 0)
		waitpid(f->pid, NULL, 0);
}

extern int pciusb_find_modules(struct pciusb_entries *entries, const char *fpciusbtable, int no_subid) {
	fh f;
	char buf[2048];
	int line;

	char *share_path = getenv("SHARE_PATH");
	char *fname;
	if (!share_path || !*share_path) share_path = "/usr/share";

	fname = alloca(strlen(share_path) + sizeof("/ldetect-lst/") + strlen(fpciusbtable)); 
	sprintf(fname, "%s/ldetect-lst/%s", share_path, fpciusbtable);

	f = fh_open(fname);

	for (line = 1; fgets(buf, sizeof(buf) - 1, f.f); line++) {
		unsigned short vendor, device, subvendor, subdevice;
		char *p = NULL, *q = NULL;
		int offset; unsigned int i;
		int nb;
		if (buf[0]=='#')
			continue; // skip comments

		nb = sscanf(buf, "0x%hx\t0x%hx\t0x%hx\t0x%hx\t%n", &vendor, &device, &subvendor, &subdevice, &offset);
		if (nb != 4) {
			nb = sscanf(buf, "0x%hx\t0x%hx\t%n", &vendor, &device, &offset);
			if (nb != 2) {
				fprintf(stderr, "%s %d: bad line\n", fpciusbtable, line);
				continue; // skip bad line
			}
		}
		for (i = 0; i < entries->nb; i++) {
			struct pciusb_entry *e = &entries->entries[i];
			if (vendor != e->vendor ||  device != e->device)
				continue; // main ids differ
			if (nb == 4 && e->subvendor == 0xffff && e->subdevice == 0xffff && !no_subid) {
				pciusb_free(entries);
				fh_close(&f);
				return 0; /* leave, let the caller call again with subids */
			}

			if (nb == 4 && !(subvendor == e->subvendor && subdevice == e->subdevice))
				continue; // subids differ
			if (!p) { // only calc text & module if not already done
				p = buf + offset + 1;
				q = strchr(p, '\t');
			}
			e->module = strcmp(p, "unknown") ? strndup(p,q-p-1) : NULL;
			ifree(e->text); /* usb.c set it so that we display something when usbtable doesn't refer that hw*/
			e->text = strndup(q+2, strlen(q)-4);
		}
	}
	fh_close(&f);
	return 1;
}

extern void pciusb_initialize(struct pciusb_entry *e) {
	e->vendor = 0xffff;
	e->device = 0xffff;
	e->subvendor = 0xffff;
	e->subdevice = 0xffff;
	e->class_ = 0;
	e->pci_bus = 0xffff;
	e->pci_device = 0xffff;
	e->pci_function = 0xffff;
	e->module = NULL;
	e->text   = NULL;
}

extern void pciusb_free(struct pciusb_entries *entries) {
	unsigned int i;
	for (i = 0; i < entries->nb; i++) {
		struct pciusb_entry *e = &entries->entries[i];
		ifree(e->module);
		ifree(e->text);
	}
	ifree(entries->entries);
}