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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /fs/cifs/cifs_unicode.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to '')
-rw-r--r--fs/cifs/cifs_unicode.c632
1 files changed, 632 insertions, 0 deletions
diff --git a/fs/cifs/cifs_unicode.c b/fs/cifs/cifs_unicode.c
new file mode 100644
index 000000000..e7582dd79
--- /dev/null
+++ b/fs/cifs/cifs_unicode.c
@@ -0,0 +1,632 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *
+ * Copyright (c) International Business Machines Corp., 2000,2009
+ * Modified by Steve French (sfrench@us.ibm.com)
+ */
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include "cifs_fs_sb.h"
+#include "cifs_unicode.h"
+#include "cifs_uniupr.h"
+#include "cifspdu.h"
+#include "cifsglob.h"
+#include "cifs_debug.h"
+
+int cifs_remap(struct cifs_sb_info *cifs_sb)
+{
+ int map_type;
+
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SFM_CHR)
+ map_type = SFM_MAP_UNI_RSVD;
+ else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
+ map_type = SFU_MAP_UNI_RSVD;
+ else
+ map_type = NO_MAP_UNI_RSVD;
+
+ return map_type;
+}
+
+/* Convert character using the SFU - "Services for Unix" remapping range */
+static bool
+convert_sfu_char(const __u16 src_char, char *target)
+{
+ /*
+ * BB: Cannot handle remapping UNI_SLASH until all the calls to
+ * build_path_from_dentry are modified, as they use slash as
+ * separator.
+ */
+ switch (src_char) {
+ case UNI_COLON:
+ *target = ':';
+ break;
+ case UNI_ASTERISK:
+ *target = '*';
+ break;
+ case UNI_QUESTION:
+ *target = '?';
+ break;
+ case UNI_PIPE:
+ *target = '|';
+ break;
+ case UNI_GRTRTHAN:
+ *target = '>';
+ break;
+ case UNI_LESSTHAN:
+ *target = '<';
+ break;
+ default:
+ return false;
+ }
+ return true;
+}
+
+/* Convert character using the SFM - "Services for Mac" remapping range */
+static bool
+convert_sfm_char(const __u16 src_char, char *target)
+{
+ if (src_char >= 0xF001 && src_char <= 0xF01F) {
+ *target = src_char - 0xF000;
+ return true;
+ }
+ switch (src_char) {
+ case SFM_COLON:
+ *target = ':';
+ break;
+ case SFM_DOUBLEQUOTE:
+ *target = '"';
+ break;
+ case SFM_ASTERISK:
+ *target = '*';
+ break;
+ case SFM_QUESTION:
+ *target = '?';
+ break;
+ case SFM_PIPE:
+ *target = '|';
+ break;
+ case SFM_GRTRTHAN:
+ *target = '>';
+ break;
+ case SFM_LESSTHAN:
+ *target = '<';
+ break;
+ case SFM_SPACE:
+ *target = ' ';
+ break;
+ case SFM_PERIOD:
+ *target = '.';
+ break;
+ default:
+ return false;
+ }
+ return true;
+}
+
+
+/*
+ * cifs_mapchar - convert a host-endian char to proper char in codepage
+ * @target - where converted character should be copied
+ * @src_char - 2 byte host-endian source character
+ * @cp - codepage to which character should be converted
+ * @map_type - How should the 7 NTFS/SMB reserved characters be mapped to UCS2?
+ *
+ * This function handles the conversion of a single character. It is the
+ * responsibility of the caller to ensure that the target buffer is large
+ * enough to hold the result of the conversion (at least NLS_MAX_CHARSET_SIZE).
+ */
+static int
+cifs_mapchar(char *target, const __u16 *from, const struct nls_table *cp,
+ int maptype)
+{
+ int len = 1;
+ __u16 src_char;
+
+ src_char = *from;
+
+ if ((maptype == SFM_MAP_UNI_RSVD) && convert_sfm_char(src_char, target))
+ return len;
+ else if ((maptype == SFU_MAP_UNI_RSVD) &&
+ convert_sfu_char(src_char, target))
+ return len;
+
+ /* if character not one of seven in special remap set */
+ len = cp->uni2char(src_char, target, NLS_MAX_CHARSET_SIZE);
+ if (len <= 0)
+ goto surrogate_pair;
+
+ return len;
+
+surrogate_pair:
+ /* convert SURROGATE_PAIR and IVS */
+ if (strcmp(cp->charset, "utf8"))
+ goto unknown;
+ len = utf16s_to_utf8s(from, 3, UTF16_LITTLE_ENDIAN, target, 6);
+ if (len <= 0)
+ goto unknown;
+ return len;
+
+unknown:
+ *target = '?';
+ len = 1;
+ return len;
+}
+
+/*
+ * cifs_from_utf16 - convert utf16le string to local charset
+ * @to - destination buffer
+ * @from - source buffer
+ * @tolen - destination buffer size (in bytes)
+ * @fromlen - source buffer size (in bytes)
+ * @codepage - codepage to which characters should be converted
+ * @mapchar - should characters be remapped according to the mapchars option?
+ *
+ * Convert a little-endian utf16le string (as sent by the server) to a string
+ * in the provided codepage. The tolen and fromlen parameters are to ensure
+ * that the code doesn't walk off of the end of the buffer (which is always
+ * a danger if the alignment of the source buffer is off). The destination
+ * string is always properly null terminated and fits in the destination
+ * buffer. Returns the length of the destination string in bytes (including
+ * null terminator).
+ *
+ * Note that some windows versions actually send multiword UTF-16 characters
+ * instead of straight UTF16-2. The linux nls routines however aren't able to
+ * deal with those characters properly. In the event that we get some of
+ * those characters, they won't be translated properly.
+ */
+int
+cifs_from_utf16(char *to, const __le16 *from, int tolen, int fromlen,
+ const struct nls_table *codepage, int map_type)
+{
+ int i, charlen, safelen;
+ int outlen = 0;
+ int nullsize = nls_nullsize(codepage);
+ int fromwords = fromlen / 2;
+ char tmp[NLS_MAX_CHARSET_SIZE];
+ __u16 ftmp[3]; /* ftmp[3] = 3array x 2bytes = 6bytes UTF-16 */
+
+ /*
+ * because the chars can be of varying widths, we need to take care
+ * not to overflow the destination buffer when we get close to the
+ * end of it. Until we get to this offset, we don't need to check
+ * for overflow however.
+ */
+ safelen = tolen - (NLS_MAX_CHARSET_SIZE + nullsize);
+
+ for (i = 0; i < fromwords; i++) {
+ ftmp[0] = get_unaligned_le16(&from[i]);
+ if (ftmp[0] == 0)
+ break;
+ if (i + 1 < fromwords)
+ ftmp[1] = get_unaligned_le16(&from[i + 1]);
+ else
+ ftmp[1] = 0;
+ if (i + 2 < fromwords)
+ ftmp[2] = get_unaligned_le16(&from[i + 2]);
+ else
+ ftmp[2] = 0;
+
+ /*
+ * check to see if converting this character might make the
+ * conversion bleed into the null terminator
+ */
+ if (outlen >= safelen) {
+ charlen = cifs_mapchar(tmp, ftmp, codepage, map_type);
+ if ((outlen + charlen) > (tolen - nullsize))
+ break;
+ }
+
+ /* put converted char into 'to' buffer */
+ charlen = cifs_mapchar(&to[outlen], ftmp, codepage, map_type);
+ outlen += charlen;
+
+ /* charlen (=bytes of UTF-8 for 1 character)
+ * 4bytes UTF-8(surrogate pair) is charlen=4
+ * (4bytes UTF-16 code)
+ * 7-8bytes UTF-8(IVS) is charlen=3+4 or 4+4
+ * (2 UTF-8 pairs divided to 2 UTF-16 pairs) */
+ if (charlen == 4)
+ i++;
+ else if (charlen >= 5)
+ /* 5-6bytes UTF-8 */
+ i += 2;
+ }
+
+ /* properly null-terminate string */
+ for (i = 0; i < nullsize; i++)
+ to[outlen++] = 0;
+
+ return outlen;
+}
+
+/*
+ * NAME: cifs_strtoUTF16()
+ *
+ * FUNCTION: Convert character string to unicode string
+ *
+ */
+int
+cifs_strtoUTF16(__le16 *to, const char *from, int len,
+ const struct nls_table *codepage)
+{
+ int charlen;
+ int i;
+ wchar_t wchar_to; /* needed to quiet sparse */
+
+ /* special case for utf8 to handle no plane0 chars */
+ if (!strcmp(codepage->charset, "utf8")) {
+ /*
+ * convert utf8 -> utf16, we assume we have enough space
+ * as caller should have assumed conversion does not overflow
+ * in destination len is length in wchar_t units (16bits)
+ */
+ i = utf8s_to_utf16s(from, len, UTF16_LITTLE_ENDIAN,
+ (wchar_t *) to, len);
+
+ /* if success terminate and exit */
+ if (i >= 0)
+ goto success;
+ /*
+ * if fails fall back to UCS encoding as this
+ * function should not return negative values
+ * currently can fail only if source contains
+ * invalid encoded characters
+ */
+ }
+
+ for (i = 0; len && *from; i++, from += charlen, len -= charlen) {
+ charlen = codepage->char2uni(from, len, &wchar_to);
+ if (charlen < 1) {
+ cifs_dbg(VFS, "strtoUTF16: char2uni of 0x%x returned %d\n",
+ *from, charlen);
+ /* A question mark */
+ wchar_to = 0x003f;
+ charlen = 1;
+ }
+ put_unaligned_le16(wchar_to, &to[i]);
+ }
+
+success:
+ put_unaligned_le16(0, &to[i]);
+ return i;
+}
+
+/*
+ * cifs_utf16_bytes - how long will a string be after conversion?
+ * @utf16 - pointer to input string
+ * @maxbytes - don't go past this many bytes of input string
+ * @codepage - destination codepage
+ *
+ * Walk a utf16le string and return the number of bytes that the string will
+ * be after being converted to the given charset, not including any null
+ * termination required. Don't walk past maxbytes in the source buffer.
+ */
+int
+cifs_utf16_bytes(const __le16 *from, int maxbytes,
+ const struct nls_table *codepage)
+{
+ int i;
+ int charlen, outlen = 0;
+ int maxwords = maxbytes / 2;
+ char tmp[NLS_MAX_CHARSET_SIZE];
+ __u16 ftmp[3];
+
+ for (i = 0; i < maxwords; i++) {
+ ftmp[0] = get_unaligned_le16(&from[i]);
+ if (ftmp[0] == 0)
+ break;
+ if (i + 1 < maxwords)
+ ftmp[1] = get_unaligned_le16(&from[i + 1]);
+ else
+ ftmp[1] = 0;
+ if (i + 2 < maxwords)
+ ftmp[2] = get_unaligned_le16(&from[i + 2]);
+ else
+ ftmp[2] = 0;
+
+ charlen = cifs_mapchar(tmp, ftmp, codepage, NO_MAP_UNI_RSVD);
+ outlen += charlen;
+ }
+
+ return outlen;
+}
+
+/*
+ * cifs_strndup_from_utf16 - copy a string from wire format to the local
+ * codepage
+ * @src - source string
+ * @maxlen - don't walk past this many bytes in the source string
+ * @is_unicode - is this a unicode string?
+ * @codepage - destination codepage
+ *
+ * Take a string given by the server, convert it to the local codepage and
+ * put it in a new buffer. Returns a pointer to the new string or NULL on
+ * error.
+ */
+char *
+cifs_strndup_from_utf16(const char *src, const int maxlen,
+ const bool is_unicode, const struct nls_table *codepage)
+{
+ int len;
+ char *dst;
+
+ if (is_unicode) {
+ len = cifs_utf16_bytes((__le16 *) src, maxlen, codepage);
+ len += nls_nullsize(codepage);
+ dst = kmalloc(len, GFP_KERNEL);
+ if (!dst)
+ return NULL;
+ cifs_from_utf16(dst, (__le16 *) src, len, maxlen, codepage,
+ NO_MAP_UNI_RSVD);
+ } else {
+ dst = kstrndup(src, maxlen, GFP_KERNEL);
+ }
+
+ return dst;
+}
+
+static __le16 convert_to_sfu_char(char src_char)
+{
+ __le16 dest_char;
+
+ switch (src_char) {
+ case ':':
+ dest_char = cpu_to_le16(UNI_COLON);
+ break;
+ case '*':
+ dest_char = cpu_to_le16(UNI_ASTERISK);
+ break;
+ case '?':
+ dest_char = cpu_to_le16(UNI_QUESTION);
+ break;
+ case '<':
+ dest_char = cpu_to_le16(UNI_LESSTHAN);
+ break;
+ case '>':
+ dest_char = cpu_to_le16(UNI_GRTRTHAN);
+ break;
+ case '|':
+ dest_char = cpu_to_le16(UNI_PIPE);
+ break;
+ default:
+ dest_char = 0;
+ }
+
+ return dest_char;
+}
+
+static __le16 convert_to_sfm_char(char src_char, bool end_of_string)
+{
+ __le16 dest_char;
+
+ if (src_char >= 0x01 && src_char <= 0x1F) {
+ dest_char = cpu_to_le16(src_char + 0xF000);
+ return dest_char;
+ }
+ switch (src_char) {
+ case ':':
+ dest_char = cpu_to_le16(SFM_COLON);
+ break;
+ case '"':
+ dest_char = cpu_to_le16(SFM_DOUBLEQUOTE);
+ break;
+ case '*':
+ dest_char = cpu_to_le16(SFM_ASTERISK);
+ break;
+ case '?':
+ dest_char = cpu_to_le16(SFM_QUESTION);
+ break;
+ case '<':
+ dest_char = cpu_to_le16(SFM_LESSTHAN);
+ break;
+ case '>':
+ dest_char = cpu_to_le16(SFM_GRTRTHAN);
+ break;
+ case '|':
+ dest_char = cpu_to_le16(SFM_PIPE);
+ break;
+ case '.':
+ if (end_of_string)
+ dest_char = cpu_to_le16(SFM_PERIOD);
+ else
+ dest_char = 0;
+ break;
+ case ' ':
+ if (end_of_string)
+ dest_char = cpu_to_le16(SFM_SPACE);
+ else
+ dest_char = 0;
+ break;
+ default:
+ dest_char = 0;
+ }
+
+ return dest_char;
+}
+
+/*
+ * Convert 16 bit Unicode pathname to wire format from string in current code
+ * page. Conversion may involve remapping up the six characters that are
+ * only legal in POSIX-like OS (if they are present in the string). Path
+ * names are little endian 16 bit Unicode on the wire
+ */
+int
+cifsConvertToUTF16(__le16 *target, const char *source, int srclen,
+ const struct nls_table *cp, int map_chars)
+{
+ int i, charlen;
+ int j = 0;
+ char src_char;
+ __le16 dst_char;
+ wchar_t tmp;
+ wchar_t *wchar_to; /* UTF-16 */
+ int ret;
+ unicode_t u;
+
+ if (map_chars == NO_MAP_UNI_RSVD)
+ return cifs_strtoUTF16(target, source, PATH_MAX, cp);
+
+ wchar_to = kzalloc(6, GFP_KERNEL);
+
+ for (i = 0; i < srclen; j++) {
+ src_char = source[i];
+ charlen = 1;
+
+ /* check if end of string */
+ if (src_char == 0)
+ goto ctoUTF16_out;
+
+ /* see if we must remap this char */
+ if (map_chars == SFU_MAP_UNI_RSVD)
+ dst_char = convert_to_sfu_char(src_char);
+ else if (map_chars == SFM_MAP_UNI_RSVD) {
+ bool end_of_string;
+
+ /**
+ * Remap spaces and periods found at the end of every
+ * component of the path. The special cases of '.' and
+ * '..' do not need to be dealt with explicitly because
+ * they are addressed in namei.c:link_path_walk().
+ **/
+ if ((i == srclen - 1) || (source[i+1] == '\\'))
+ end_of_string = true;
+ else
+ end_of_string = false;
+
+ dst_char = convert_to_sfm_char(src_char, end_of_string);
+ } else
+ dst_char = 0;
+ /*
+ * FIXME: We can not handle remapping backslash (UNI_SLASH)
+ * until all the calls to build_path_from_dentry are modified,
+ * as they use backslash as separator.
+ */
+ if (dst_char == 0) {
+ charlen = cp->char2uni(source + i, srclen - i, &tmp);
+ dst_char = cpu_to_le16(tmp);
+
+ /*
+ * if no match, use question mark, which at least in
+ * some cases serves as wild card
+ */
+ if (charlen > 0)
+ goto ctoUTF16;
+
+ /* convert SURROGATE_PAIR */
+ if (strcmp(cp->charset, "utf8") || !wchar_to)
+ goto unknown;
+ if (*(source + i) & 0x80) {
+ charlen = utf8_to_utf32(source + i, 6, &u);
+ if (charlen < 0)
+ goto unknown;
+ } else
+ goto unknown;
+ ret = utf8s_to_utf16s(source + i, charlen,
+ UTF16_LITTLE_ENDIAN,
+ wchar_to, 6);
+ if (ret < 0)
+ goto unknown;
+
+ i += charlen;
+ dst_char = cpu_to_le16(*wchar_to);
+ if (charlen <= 3)
+ /* 1-3bytes UTF-8 to 2bytes UTF-16 */
+ put_unaligned(dst_char, &target[j]);
+ else if (charlen == 4) {
+ /* 4bytes UTF-8(surrogate pair) to 4bytes UTF-16
+ * 7-8bytes UTF-8(IVS) divided to 2 UTF-16
+ * (charlen=3+4 or 4+4) */
+ put_unaligned(dst_char, &target[j]);
+ dst_char = cpu_to_le16(*(wchar_to + 1));
+ j++;
+ put_unaligned(dst_char, &target[j]);
+ } else if (charlen >= 5) {
+ /* 5-6bytes UTF-8 to 6bytes UTF-16 */
+ put_unaligned(dst_char, &target[j]);
+ dst_char = cpu_to_le16(*(wchar_to + 1));
+ j++;
+ put_unaligned(dst_char, &target[j]);
+ dst_char = cpu_to_le16(*(wchar_to + 2));
+ j++;
+ put_unaligned(dst_char, &target[j]);
+ }
+ continue;
+
+unknown:
+ dst_char = cpu_to_le16(0x003f);
+ charlen = 1;
+ }
+
+ctoUTF16:
+ /*
+ * character may take more than one byte in the source string,
+ * but will take exactly two bytes in the target string
+ */
+ i += charlen;
+ put_unaligned(dst_char, &target[j]);
+ }
+
+ctoUTF16_out:
+ put_unaligned(0, &target[j]); /* Null terminate target unicode string */
+ kfree(wchar_to);
+ return j;
+}
+
+/*
+ * cifs_local_to_utf16_bytes - how long will a string be after conversion?
+ * @from - pointer to input string
+ * @maxbytes - don't go past this many bytes of input string
+ * @codepage - source codepage
+ *
+ * Walk a string and return the number of bytes that the string will
+ * be after being converted to the given charset, not including any null
+ * termination required. Don't walk past maxbytes in the source buffer.
+ */
+
+static int
+cifs_local_to_utf16_bytes(const char *from, int len,
+ const struct nls_table *codepage)
+{
+ int charlen;
+ int i;
+ wchar_t wchar_to;
+
+ for (i = 0; len && *from; i++, from += charlen, len -= charlen) {
+ charlen = codepage->char2uni(from, len, &wchar_to);
+ /* Failed conversion defaults to a question mark */
+ if (charlen < 1)
+ charlen = 1;
+ }
+ return 2 * i; /* UTF16 characters are two bytes */
+}
+
+/*
+ * cifs_strndup_to_utf16 - copy a string to wire format from the local codepage
+ * @src - source string
+ * @maxlen - don't walk past this many bytes in the source string
+ * @utf16_len - the length of the allocated string in bytes (including null)
+ * @cp - source codepage
+ * @remap - map special chars
+ *
+ * Take a string convert it from the local codepage to UTF16 and
+ * put it in a new buffer. Returns a pointer to the new string or NULL on
+ * error.
+ */
+__le16 *
+cifs_strndup_to_utf16(const char *src, const int maxlen, int *utf16_len,
+ const struct nls_table *cp, int remap)
+{
+ int len;
+ __le16 *dst;
+
+ len = cifs_local_to_utf16_bytes(src, maxlen, cp);
+ len += 2; /* NULL */
+ dst = kmalloc(len, GFP_KERNEL);
+ if (!dst) {
+ *utf16_len = 0;
+ return NULL;
+ }
+ cifsConvertToUTF16(dst, src, strlen(src), cp, remap);
+ *utf16_len = len;
+ return dst;
+}