main.c

klibc精简化的c程序库

#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <arpa/inet.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <setjmp.h>
#include <sys/wait.h>
#include <unistd.h>
#include <klibc/sysconfig.h>	/* For _KLIBC_NO_MMU */

#include <linux/nfs_mount.h>

#include "nfsmount.h"
#include "sunrpc.h"
#include "dummypmap.h"

const char *progname;
static jmp_buf abort_buf;

static struct nfs_mount_data mount_data = {
	.version	= NFS_MOUNT_VERSION,
	.flags		= NFS_MOUNT_NONLM | NFS_MOUNT_VER3 | NFS_MOUNT_TCP,
	.rsize		= 0,	/* Server's choice */
	.wsize		= 0,	/* Server's choice */
	.timeo		= 7,
	.retrans	= 3,
	.acregmin	= 3,
	.acregmax	= 60,
	.acdirmin	= 30,
	.acdirmax	= 60,
	.namlen		= NAME_MAX,
};

int nfs_port;

static struct int_opts {
	char *name;
	int *val;
} int_opts[] = {
	{"port",	&nfs_port},
	{"rsize",	&mount_data.rsize},
	{"wsize",	&mount_data.wsize},
	{"timeo",	&mount_data.timeo},
	{"retrans",	&mount_data.retrans},
	{"acregmin",	&mount_data.acregmin},
	{"acregmax",	&mount_data.acregmax},
	{"acdirmin",	&mount_data.acdirmin},
	{"acdirmax",	&mount_data.acdirmax},
	{NULL, NULL}
};

static struct bool_opts {
	char *name;
	int and_mask;
	int or_mask;
} bool_opts[] = {
	{"soft", ~NFS_MOUNT_SOFT, NFS_MOUNT_SOFT},
	{"hard", ~NFS_MOUNT_SOFT, 0},
	{"intr", ~NFS_MOUNT_INTR, NFS_MOUNT_INTR},
	{"nointr", ~NFS_MOUNT_INTR, 0},
	{"posix", ~NFS_MOUNT_POSIX, NFS_MOUNT_POSIX},
	{"noposix", ~NFS_MOUNT_POSIX, 0},
	{"cto", ~NFS_MOUNT_NOCTO, 0},
	{"nocto", ~NFS_MOUNT_NOCTO, NFS_MOUNT_NOCTO},
	{"ac", ~NFS_MOUNT_NOAC, 0},
	{"noac", ~NFS_MOUNT_NOAC, NFS_MOUNT_NOAC},
	{"lock", ~NFS_MOUNT_NONLM, 0},
	{"nolock", ~NFS_MOUNT_NONLM, NFS_MOUNT_NONLM},
	{"v2", ~NFS_MOUNT_VER3, 0},
	{"v3", ~NFS_MOUNT_VER3, NFS_MOUNT_VER3},
	{"udp", ~NFS_MOUNT_TCP, 0},
	{"tcp", ~NFS_MOUNT_TCP, NFS_MOUNT_TCP},
	{"broken_suid", ~NFS_MOUNT_BROKEN_SUID, NFS_MOUNT_BROKEN_SUID},
	{"ro", ~NFS_MOUNT_KLIBC_RONLY, NFS_MOUNT_KLIBC_RONLY},
	{"rw", ~NFS_MOUNT_KLIBC_RONLY, 0},
	{NULL, 0, 0}
};

static int parse_int(const char *val, const char *ctx)
{
	char *end;
	int ret;

	ret = (int)strtoul(val, &end, 0);
	if (*val == '\0' || *end != '\0') {
		fprintf(stderr, "%s: invalid value for %s\n", val, ctx);
		longjmp(abort_buf, 1);
	}
	return ret;
}

static void parse_opts(char *opts)
{
	char *cp, *val;

	while ((cp = strsep(&opts, ",")) != NULL) {
		if (*cp == '\0')
			continue;
		if ((val = strchr(cp, '=')) != NULL) {
			struct int_opts *opts = int_opts;
			*val++ = '\0';
			while (opts->name && strcmp(opts->name, cp) != 0)
				opts++;
			if (opts->name)
				*(opts->val) = parse_int(val, opts->name);
			else {
				fprintf(stderr, "%s: bad option '%s'\n",
					progname, cp);
				longjmp(abort_buf, 1);
			}
		} else {
			struct bool_opts *opts = bool_opts;
			while (opts->name && strcmp(opts->name, cp) != 0)
				opts++;
			if (opts->name) {
				mount_data.flags &= opts->and_mask;
				mount_data.flags |= opts->or_mask;
			} else {
				fprintf(stderr, "%s: bad option '%s'\n",
					progname, cp);
				longjmp(abort_buf, 1);
			}
		}
	}
}

static uint32_t parse_addr(const char *ip)
{
	struct in_addr in;
	if (inet_aton(ip, &in) == 0) {
		fprintf(stderr, "%s: can't parse IP address '%s'\n",
			progname, ip);
		longjmp(abort_buf, 1);
	}
	return in.s_addr;
}

static void check_path(const char *path)
{
	struct stat st;

	if (stat(path, &st) == -1) {
		perror("stat");
		longjmp(abort_buf, 1);
	} else if (!S_ISDIR(st.st_mode)) {
		fprintf(stderr, "%s: '%s' not a directory\n", progname, path);
		longjmp(abort_buf, 1);
	}
}

int main(int argc, char *argv[])
    __attribute__ ((weak, alias("nfsmount_main")));

int nfsmount_main(int argc, char *argv[])
{
	uint32_t server;
	char *rem_name;
	char *rem_path;
	char *hostname;
	char *path;
	int c;
	const char *portmap_file;
	pid_t spoof_portmap;
	int err;

	if ((err = setjmp(abort_buf)))
		return err;

	/* Set these here to avoid longjmp warning */
	portmap_file = NULL;
	spoof_portmap = 0;
	server = 0;

	/* If progname is set we're invoked from another program */
	if (!progname) {
		struct timeval now;
		progname = argv[0];
		gettimeofday(&now, NULL);
		srand48(now.tv_usec ^ (now.tv_sec << 24));
	}

	while ((c = getopt(argc, argv, "o:p:")) != EOF) {
		switch (c) {
		case 'o':
			parse_opts(optarg);
			break;
		case 'p':
			portmap_file = optarg;
			break;
		case '?':
			fprintf(stderr, "%s: invalid option -%c\n",
				progname, optopt);
			return 1;
		}
	}

	if (optind == argc) {
		fprintf(stderr, "%s: need a path\n", progname);
		return 1;
	}

	hostname = rem_path = argv[optind];

	if ((rem_name = strdup(rem_path)) == NULL) {
		perror("strdup");
		return 1;
	}

	if ((rem_path = strchr(rem_path, ':')) == NULL) {
		fprintf(stderr, "%s: need a server\n", progname);
		return 1;
	}

	*rem_path++ = '\0';

	if (*rem_path != '/') {
		fprintf(stderr, "%s: need a path\n", progname);
		return 1;
	}

	server = parse_addr(hostname);

	if (optind <= argc - 2)
		path = argv[optind + 1];
	else
		path = "/nfs_root";

	check_path(path);

#if! _KLIBC_NO_MMU
	/* Note: uClinux can't fork(), so the spoof portmapper is not
	   available on uClinux. */
	if (portmap_file)
		spoof_portmap = start_dummy_portmap(portmap_file);

	if (spoof_portmap == -1)
		return 1;
#endif

	if (nfs_mount(rem_name, hostname, server, rem_path, path,
		      &mount_data) != 0)
		return 1;

	/* If we set up the spoofer, tear it down now */
	if (spoof_portmap) {
		kill(SIGTERM, spoof_portmap);
		while (waitpid(spoof_portmap, NULL, 0) == -1 &&
		       errno == EINTR)
		  ;
	}

	free(rem_name);

	return 0;
}