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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 /drivers/media/v4l2-core/v4l2-jpeg.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 'drivers/media/v4l2-core/v4l2-jpeg.c')
-rw-r--r--drivers/media/v4l2-core/v4l2-jpeg.c677
1 files changed, 677 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/v4l2-jpeg.c b/drivers/media/v4l2-core/v4l2-jpeg.c
new file mode 100644
index 000000000..c2513b775
--- /dev/null
+++ b/drivers/media/v4l2-core/v4l2-jpeg.c
@@ -0,0 +1,677 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * V4L2 JPEG header parser helpers.
+ *
+ * Copyright (C) 2019 Pengutronix, Philipp Zabel <kernel@pengutronix.de>
+ *
+ * For reference, see JPEG ITU-T.81 (ISO/IEC 10918-1) [1]
+ *
+ * [1] https://www.w3.org/Graphics/JPEG/itu-t81.pdf
+ */
+
+#include <asm/unaligned.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <media/v4l2-jpeg.h>
+
+MODULE_DESCRIPTION("V4L2 JPEG header parser helpers");
+MODULE_AUTHOR("Philipp Zabel <kernel@pengutronix.de>");
+MODULE_LICENSE("GPL");
+
+/* Table B.1 - Marker code assignments */
+#define SOF0 0xffc0 /* start of frame */
+#define SOF1 0xffc1
+#define SOF2 0xffc2
+#define SOF3 0xffc3
+#define SOF5 0xffc5
+#define SOF7 0xffc7
+#define JPG 0xffc8 /* extensions */
+#define SOF9 0xffc9
+#define SOF11 0xffcb
+#define SOF13 0xffcd
+#define SOF15 0xffcf
+#define DHT 0xffc4 /* huffman table */
+#define DAC 0xffcc /* arithmetic coding conditioning */
+#define RST0 0xffd0 /* restart */
+#define RST7 0xffd7
+#define SOI 0xffd8 /* start of image */
+#define EOI 0xffd9 /* end of image */
+#define SOS 0xffda /* start of stream */
+#define DQT 0xffdb /* quantization table */
+#define DNL 0xffdc /* number of lines */
+#define DRI 0xffdd /* restart interval */
+#define DHP 0xffde /* hierarchical progression */
+#define EXP 0xffdf /* expand reference */
+#define APP0 0xffe0 /* application data */
+#define APP14 0xffee /* application data for colour encoding */
+#define APP15 0xffef
+#define JPG0 0xfff0 /* extensions */
+#define JPG13 0xfffd
+#define COM 0xfffe /* comment */
+#define TEM 0xff01 /* temporary */
+
+/**
+ * struct jpeg_stream - JPEG byte stream
+ * @curr: current position in stream
+ * @end: end position, after last byte
+ */
+struct jpeg_stream {
+ u8 *curr;
+ u8 *end;
+};
+
+/* returns a value that fits into u8, or negative error */
+static int jpeg_get_byte(struct jpeg_stream *stream)
+{
+ if (stream->curr >= stream->end)
+ return -EINVAL;
+
+ return *stream->curr++;
+}
+
+/* returns a value that fits into u16, or negative error */
+static int jpeg_get_word_be(struct jpeg_stream *stream)
+{
+ u16 word;
+
+ if (stream->curr + sizeof(__be16) > stream->end)
+ return -EINVAL;
+
+ word = get_unaligned_be16(stream->curr);
+ stream->curr += sizeof(__be16);
+
+ return word;
+}
+
+static int jpeg_skip(struct jpeg_stream *stream, size_t len)
+{
+ if (stream->curr + len > stream->end)
+ return -EINVAL;
+
+ stream->curr += len;
+
+ return 0;
+}
+
+static int jpeg_next_marker(struct jpeg_stream *stream)
+{
+ int byte;
+ u16 marker = 0;
+
+ while ((byte = jpeg_get_byte(stream)) >= 0) {
+ marker = (marker << 8) | byte;
+ /* skip stuffing bytes and REServed markers */
+ if (marker == TEM || (marker > 0xffbf && marker < 0xffff))
+ return marker;
+ }
+
+ return byte;
+}
+
+/* this does not advance the current position in the stream */
+static int jpeg_reference_segment(struct jpeg_stream *stream,
+ struct v4l2_jpeg_reference *segment)
+{
+ u16 len;
+
+ if (stream->curr + sizeof(__be16) > stream->end)
+ return -EINVAL;
+
+ len = get_unaligned_be16(stream->curr);
+ if (stream->curr + len > stream->end)
+ return -EINVAL;
+
+ segment->start = stream->curr;
+ segment->length = len;
+
+ return 0;
+}
+
+static int v4l2_jpeg_decode_subsampling(u8 nf, u8 h_v)
+{
+ if (nf == 1)
+ return V4L2_JPEG_CHROMA_SUBSAMPLING_GRAY;
+
+ /* no chroma subsampling for 4-component images */
+ if (nf == 4 && h_v != 0x11)
+ return -EINVAL;
+
+ switch (h_v) {
+ case 0x11:
+ return V4L2_JPEG_CHROMA_SUBSAMPLING_444;
+ case 0x21:
+ return V4L2_JPEG_CHROMA_SUBSAMPLING_422;
+ case 0x22:
+ return V4L2_JPEG_CHROMA_SUBSAMPLING_420;
+ case 0x41:
+ return V4L2_JPEG_CHROMA_SUBSAMPLING_411;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int jpeg_parse_frame_header(struct jpeg_stream *stream, u16 sof_marker,
+ struct v4l2_jpeg_frame_header *frame_header)
+{
+ int len = jpeg_get_word_be(stream);
+
+ if (len < 0)
+ return len;
+ /* Lf = 8 + 3 * Nf, Nf >= 1 */
+ if (len < 8 + 3)
+ return -EINVAL;
+
+ if (frame_header) {
+ /* Table B.2 - Frame header parameter sizes and values */
+ int p, y, x, nf;
+ int i;
+
+ p = jpeg_get_byte(stream);
+ if (p < 0)
+ return p;
+ /*
+ * Baseline DCT only supports 8-bit precision.
+ * Extended sequential DCT also supports 12-bit precision.
+ */
+ if (p != 8 && (p != 12 || sof_marker != SOF1))
+ return -EINVAL;
+
+ y = jpeg_get_word_be(stream);
+ if (y < 0)
+ return y;
+ if (y == 0)
+ return -EINVAL;
+
+ x = jpeg_get_word_be(stream);
+ if (x < 0)
+ return x;
+ if (x == 0)
+ return -EINVAL;
+
+ nf = jpeg_get_byte(stream);
+ if (nf < 0)
+ return nf;
+ /*
+ * The spec allows 1 <= Nf <= 255, but we only support up to 4
+ * components.
+ */
+ if (nf < 1 || nf > V4L2_JPEG_MAX_COMPONENTS)
+ return -EINVAL;
+ if (len != 8 + 3 * nf)
+ return -EINVAL;
+
+ frame_header->precision = p;
+ frame_header->height = y;
+ frame_header->width = x;
+ frame_header->num_components = nf;
+
+ for (i = 0; i < nf; i++) {
+ struct v4l2_jpeg_frame_component_spec *component;
+ int c, h_v, tq;
+
+ c = jpeg_get_byte(stream);
+ if (c < 0)
+ return c;
+
+ h_v = jpeg_get_byte(stream);
+ if (h_v < 0)
+ return h_v;
+ if (i == 0) {
+ int subs;
+
+ subs = v4l2_jpeg_decode_subsampling(nf, h_v);
+ if (subs < 0)
+ return subs;
+ frame_header->subsampling = subs;
+ } else if (h_v != 0x11) {
+ /* all chroma sampling factors must be 1 */
+ return -EINVAL;
+ }
+
+ tq = jpeg_get_byte(stream);
+ if (tq < 0)
+ return tq;
+
+ component = &frame_header->component[i];
+ component->component_identifier = c;
+ component->horizontal_sampling_factor =
+ (h_v >> 4) & 0xf;
+ component->vertical_sampling_factor = h_v & 0xf;
+ component->quantization_table_selector = tq;
+ }
+ } else {
+ return jpeg_skip(stream, len - 2);
+ }
+
+ return 0;
+}
+
+static int jpeg_parse_scan_header(struct jpeg_stream *stream,
+ struct v4l2_jpeg_scan_header *scan_header)
+{
+ size_t skip;
+ int len = jpeg_get_word_be(stream);
+
+ if (len < 0)
+ return len;
+ /* Ls = 8 + 3 * Ns, Ns >= 1 */
+ if (len < 6 + 2)
+ return -EINVAL;
+
+ if (scan_header) {
+ int ns;
+ int i;
+
+ ns = jpeg_get_byte(stream);
+ if (ns < 0)
+ return ns;
+ if (ns < 1 || ns > 4 || len != 6 + 2 * ns)
+ return -EINVAL;
+
+ scan_header->num_components = ns;
+
+ for (i = 0; i < ns; i++) {
+ struct v4l2_jpeg_scan_component_spec *component;
+ int cs, td_ta;
+
+ cs = jpeg_get_byte(stream);
+ if (cs < 0)
+ return cs;
+
+ td_ta = jpeg_get_byte(stream);
+ if (td_ta < 0)
+ return td_ta;
+
+ component = &scan_header->component[i];
+ component->component_selector = cs;
+ component->dc_entropy_coding_table_selector =
+ (td_ta >> 4) & 0xf;
+ component->ac_entropy_coding_table_selector =
+ td_ta & 0xf;
+ }
+
+ skip = 3; /* skip Ss, Se, Ah, and Al */
+ } else {
+ skip = len - 2;
+ }
+
+ return jpeg_skip(stream, skip);
+}
+
+/* B.2.4.1 Quantization table-specification syntax */
+static int jpeg_parse_quantization_tables(struct jpeg_stream *stream,
+ u8 precision,
+ struct v4l2_jpeg_reference *tables)
+{
+ int len = jpeg_get_word_be(stream);
+
+ if (len < 0)
+ return len;
+ /* Lq = 2 + n * 65 (for baseline DCT), n >= 1 */
+ if (len < 2 + 65)
+ return -EINVAL;
+
+ len -= 2;
+ while (len >= 65) {
+ u8 pq, tq, *qk;
+ int ret;
+ int pq_tq = jpeg_get_byte(stream);
+
+ if (pq_tq < 0)
+ return pq_tq;
+
+ /* quantization table element precision */
+ pq = (pq_tq >> 4) & 0xf;
+ /*
+ * Only 8-bit Qk values for 8-bit sample precision. Extended
+ * sequential DCT with 12-bit sample precision also supports
+ * 16-bit Qk values.
+ */
+ if (pq != 0 && (pq != 1 || precision != 12))
+ return -EINVAL;
+
+ /* quantization table destination identifier */
+ tq = pq_tq & 0xf;
+ if (tq > 3)
+ return -EINVAL;
+
+ /* quantization table element */
+ qk = stream->curr;
+ ret = jpeg_skip(stream, pq ? 128 : 64);
+ if (ret < 0)
+ return -EINVAL;
+
+ if (tables) {
+ tables[tq].start = qk;
+ tables[tq].length = pq ? 128 : 64;
+ }
+
+ len -= pq ? 129 : 65;
+ }
+
+ return 0;
+}
+
+/* B.2.4.2 Huffman table-specification syntax */
+static int jpeg_parse_huffman_tables(struct jpeg_stream *stream,
+ struct v4l2_jpeg_reference *tables)
+{
+ int mt;
+ int len = jpeg_get_word_be(stream);
+
+ if (len < 0)
+ return len;
+ /* Table B.5 - Huffman table specification parameter sizes and values */
+ if (len < 2 + 17)
+ return -EINVAL;
+
+ for (len -= 2; len >= 17; len -= 17 + mt) {
+ u8 tc, th, *table;
+ int tc_th = jpeg_get_byte(stream);
+ int i, ret;
+
+ if (tc_th < 0)
+ return tc_th;
+
+ /* table class - 0 = DC, 1 = AC */
+ tc = (tc_th >> 4) & 0xf;
+ if (tc > 1)
+ return -EINVAL;
+
+ /* huffman table destination identifier */
+ th = tc_th & 0xf;
+ /* only two Huffman tables for baseline DCT */
+ if (th > 1)
+ return -EINVAL;
+
+ /* BITS - number of Huffman codes with length i */
+ table = stream->curr;
+ mt = 0;
+ for (i = 0; i < 16; i++) {
+ int li;
+
+ li = jpeg_get_byte(stream);
+ if (li < 0)
+ return li;
+
+ mt += li;
+ }
+ /* HUFFVAL - values associated with each Huffman code */
+ ret = jpeg_skip(stream, mt);
+ if (ret < 0)
+ return ret;
+
+ if (tables) {
+ tables[(tc << 1) | th].start = table;
+ tables[(tc << 1) | th].length = stream->curr - table;
+ }
+ }
+
+ return jpeg_skip(stream, len - 2);
+}
+
+/* B.2.4.4 Restart interval definition syntax */
+static int jpeg_parse_restart_interval(struct jpeg_stream *stream,
+ u16 *restart_interval)
+{
+ int len = jpeg_get_word_be(stream);
+ int ri;
+
+ if (len < 0)
+ return len;
+ if (len != 4)
+ return -EINVAL;
+
+ ri = jpeg_get_word_be(stream);
+ if (ri < 0)
+ return ri;
+
+ *restart_interval = ri;
+
+ return 0;
+}
+
+static int jpeg_skip_segment(struct jpeg_stream *stream)
+{
+ int len = jpeg_get_word_be(stream);
+
+ if (len < 0)
+ return len;
+ if (len < 2)
+ return -EINVAL;
+
+ return jpeg_skip(stream, len - 2);
+}
+
+/* Rec. ITU-T T.872 (06/2012) 6.5.3 */
+static int jpeg_parse_app14_data(struct jpeg_stream *stream,
+ enum v4l2_jpeg_app14_tf *tf)
+{
+ int ret;
+ int lp;
+ int skip;
+
+ lp = jpeg_get_word_be(stream);
+ if (lp < 0)
+ return lp;
+
+ /* Check for "Adobe\0" in Ap1..6 */
+ if (stream->curr + 6 > stream->end ||
+ strncmp(stream->curr, "Adobe\0", 6))
+ return -EINVAL;
+
+ /* get to Ap12 */
+ ret = jpeg_skip(stream, 11);
+ if (ret < 0)
+ return ret;
+
+ ret = jpeg_get_byte(stream);
+ if (ret < 0)
+ return ret;
+
+ *tf = ret;
+
+ /* skip the rest of the segment, this ensures at least it is complete */
+ skip = lp - 2 - 11;
+ return jpeg_skip(stream, skip);
+}
+
+/**
+ * v4l2_jpeg_parse_header - locate marker segments and optionally parse headers
+ * @buf: address of the JPEG buffer, should start with a SOI marker
+ * @len: length of the JPEG buffer
+ * @out: returns marker segment positions and optionally parsed headers
+ *
+ * The out->scan_header pointer must be initialized to NULL or point to a valid
+ * v4l2_jpeg_scan_header structure. The out->huffman_tables and
+ * out->quantization_tables pointers must be initialized to NULL or point to a
+ * valid array of 4 v4l2_jpeg_reference structures each.
+ *
+ * Returns 0 or negative error if parsing failed.
+ */
+int v4l2_jpeg_parse_header(void *buf, size_t len, struct v4l2_jpeg_header *out)
+{
+ struct jpeg_stream stream;
+ int marker;
+ int ret = 0;
+
+ stream.curr = buf;
+ stream.end = stream.curr + len;
+
+ out->num_dht = 0;
+ out->num_dqt = 0;
+
+ /* the first bytes must be SOI, B.2.1 High-level syntax */
+ if (jpeg_get_word_be(&stream) != SOI)
+ return -EINVAL;
+
+ /* init value to signal if this marker is not present */
+ out->app14_tf = V4L2_JPEG_APP14_TF_UNKNOWN;
+
+ /* loop through marker segments */
+ while ((marker = jpeg_next_marker(&stream)) >= 0) {
+ switch (marker) {
+ /* baseline DCT, extended sequential DCT */
+ case SOF0 ... SOF1:
+ ret = jpeg_reference_segment(&stream, &out->sof);
+ if (ret < 0)
+ return ret;
+ ret = jpeg_parse_frame_header(&stream, marker,
+ &out->frame);
+ break;
+ /* progressive, lossless */
+ case SOF2 ... SOF3:
+ /* differential coding */
+ case SOF5 ... SOF7:
+ /* arithmetic coding */
+ case SOF9 ... SOF11:
+ case SOF13 ... SOF15:
+ case DAC:
+ case TEM:
+ return -EINVAL;
+
+ case DHT:
+ ret = jpeg_reference_segment(&stream,
+ &out->dht[out->num_dht++ % 4]);
+ if (ret < 0)
+ return ret;
+ if (!out->huffman_tables) {
+ ret = jpeg_skip_segment(&stream);
+ break;
+ }
+ ret = jpeg_parse_huffman_tables(&stream,
+ out->huffman_tables);
+ break;
+ case DQT:
+ ret = jpeg_reference_segment(&stream,
+ &out->dqt[out->num_dqt++ % 4]);
+ if (ret < 0)
+ return ret;
+ if (!out->quantization_tables) {
+ ret = jpeg_skip_segment(&stream);
+ break;
+ }
+ ret = jpeg_parse_quantization_tables(&stream,
+ out->frame.precision,
+ out->quantization_tables);
+ break;
+ case DRI:
+ ret = jpeg_parse_restart_interval(&stream,
+ &out->restart_interval);
+ break;
+ case APP14:
+ ret = jpeg_parse_app14_data(&stream,
+ &out->app14_tf);
+ break;
+ case SOS:
+ ret = jpeg_reference_segment(&stream, &out->sos);
+ if (ret < 0)
+ return ret;
+ ret = jpeg_parse_scan_header(&stream, out->scan);
+ /*
+ * stop parsing, the scan header marks the beginning of
+ * the entropy coded segment
+ */
+ out->ecs_offset = stream.curr - (u8 *)buf;
+ return ret;
+
+ /* markers without parameters */
+ case RST0 ... RST7: /* restart */
+ case SOI: /* start of image */
+ case EOI: /* end of image */
+ break;
+
+ /* skip unknown or unsupported marker segments */
+ default:
+ ret = jpeg_skip_segment(&stream);
+ break;
+ }
+ if (ret < 0)
+ return ret;
+ }
+
+ return marker;
+}
+EXPORT_SYMBOL_GPL(v4l2_jpeg_parse_header);
+
+/**
+ * v4l2_jpeg_parse_frame_header - parse frame header
+ * @buf: address of the frame header, after the SOF0 marker
+ * @len: length of the frame header
+ * @frame_header: returns the parsed frame header
+ *
+ * Returns 0 or negative error if parsing failed.
+ */
+int v4l2_jpeg_parse_frame_header(void *buf, size_t len,
+ struct v4l2_jpeg_frame_header *frame_header)
+{
+ struct jpeg_stream stream;
+
+ stream.curr = buf;
+ stream.end = stream.curr + len;
+ return jpeg_parse_frame_header(&stream, SOF0, frame_header);
+}
+EXPORT_SYMBOL_GPL(v4l2_jpeg_parse_frame_header);
+
+/**
+ * v4l2_jpeg_parse_scan_header - parse scan header
+ * @buf: address of the scan header, after the SOS marker
+ * @len: length of the scan header
+ * @scan_header: returns the parsed scan header
+ *
+ * Returns 0 or negative error if parsing failed.
+ */
+int v4l2_jpeg_parse_scan_header(void *buf, size_t len,
+ struct v4l2_jpeg_scan_header *scan_header)
+{
+ struct jpeg_stream stream;
+
+ stream.curr = buf;
+ stream.end = stream.curr + len;
+ return jpeg_parse_scan_header(&stream, scan_header);
+}
+EXPORT_SYMBOL_GPL(v4l2_jpeg_parse_scan_header);
+
+/**
+ * v4l2_jpeg_parse_quantization_tables - parse quantization tables segment
+ * @buf: address of the quantization table segment, after the DQT marker
+ * @len: length of the quantization table segment
+ * @precision: sample precision (P) in bits per component
+ * @q_tables: returns four references into the buffer for the
+ * four possible quantization table destinations
+ *
+ * Returns 0 or negative error if parsing failed.
+ */
+int v4l2_jpeg_parse_quantization_tables(void *buf, size_t len, u8 precision,
+ struct v4l2_jpeg_reference *q_tables)
+{
+ struct jpeg_stream stream;
+
+ stream.curr = buf;
+ stream.end = stream.curr + len;
+ return jpeg_parse_quantization_tables(&stream, precision, q_tables);
+}
+EXPORT_SYMBOL_GPL(v4l2_jpeg_parse_quantization_tables);
+
+/**
+ * v4l2_jpeg_parse_huffman_tables - parse huffman tables segment
+ * @buf: address of the Huffman table segment, after the DHT marker
+ * @len: length of the Huffman table segment
+ * @huffman_tables: returns four references into the buffer for the
+ * four possible Huffman table destinations, in
+ * the order DC0, DC1, AC0, AC1
+ *
+ * Returns 0 or negative error if parsing failed.
+ */
+int v4l2_jpeg_parse_huffman_tables(void *buf, size_t len,
+ struct v4l2_jpeg_reference *huffman_tables)
+{
+ struct jpeg_stream stream;
+
+ stream.curr = buf;
+ stream.end = stream.curr + len;
+ return jpeg_parse_huffman_tables(&stream, huffman_tables);
+}
+EXPORT_SYMBOL_GPL(v4l2_jpeg_parse_huffman_tables);