cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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cifsroot.c (2104B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * SMB root file system support
      4 *
      5 * Copyright (c) 2019 Paulo Alcantara <palcantara@suse.de>
      6 */
      7#include <linux/init.h>
      8#include <linux/fs.h>
      9#include <linux/types.h>
     10#include <linux/ctype.h>
     11#include <linux/string.h>
     12#include <linux/root_dev.h>
     13#include <linux/kernel.h>
     14#include <linux/in.h>
     15#include <linux/inet.h>
     16#include <net/ipconfig.h>
     17
     18#define DEFAULT_MNT_OPTS \
     19	"vers=1.0,cifsacl,mfsymlinks,rsize=1048576,wsize=65536,uid=0,gid=0," \
     20	"hard,rootfs"
     21
     22static char root_dev[2048] __initdata = "";
     23static char root_opts[1024] __initdata = DEFAULT_MNT_OPTS;
     24
     25static __be32 __init parse_srvaddr(char *start, char *end)
     26{
     27	/* TODO: ipv6 support */
     28	char addr[sizeof("aaa.bbb.ccc.ddd")];
     29	int i = 0;
     30
     31	while (start < end && i < sizeof(addr) - 1) {
     32		if (isdigit(*start) || *start == '.')
     33			addr[i++] = *start;
     34		start++;
     35	}
     36	addr[i] = '\0';
     37	return in_aton(addr);
     38}
     39
     40/* cifsroot=//<server-ip>/<share>[,options] */
     41static int __init cifs_root_setup(char *line)
     42{
     43	char *s;
     44	int len;
     45	__be32 srvaddr = htonl(INADDR_NONE);
     46
     47	ROOT_DEV = Root_CIFS;
     48
     49	if (strlen(line) > 3 && line[0] == '/' && line[1] == '/') {
     50		s = strchr(&line[2], '/');
     51		if (!s || s[1] == '\0')
     52			return 1;
     53
     54		/* make s point to ',' or '\0' at end of line */
     55		s = strchrnul(s, ',');
     56		/* len is strlen(unc) + '\0' */
     57		len = s - line + 1;
     58		if (len > sizeof(root_dev)) {
     59			pr_err("Root-CIFS: UNC path too long\n");
     60			return 1;
     61		}
     62		strlcpy(root_dev, line, len);
     63		srvaddr = parse_srvaddr(&line[2], s);
     64		if (*s) {
     65			int n = snprintf(root_opts,
     66					 sizeof(root_opts), "%s,%s",
     67					 DEFAULT_MNT_OPTS, s + 1);
     68			if (n >= sizeof(root_opts)) {
     69				pr_err("Root-CIFS: mount options string too long\n");
     70				root_opts[sizeof(root_opts)-1] = '\0';
     71				return 1;
     72			}
     73		}
     74	}
     75
     76	root_server_addr = srvaddr;
     77
     78	return 1;
     79}
     80
     81__setup("cifsroot=", cifs_root_setup);
     82
     83int __init cifs_root_data(char **dev, char **opts)
     84{
     85	if (!root_dev[0] || root_server_addr == htonl(INADDR_NONE)) {
     86		pr_err("Root-CIFS: no SMB server address\n");
     87		return -1;
     88	}
     89
     90	*dev = root_dev;
     91	*opts = root_opts;
     92
     93	return 0;
     94}