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-rw-r--r--include/linux/skbuff.h419
1 files changed, 283 insertions, 136 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 3a30cae8b0a5..da96f0d3e753 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -42,99 +42,114 @@
#if IS_ENABLED(CONFIG_NF_CONNTRACK)
#include <linux/netfilter/nf_conntrack_common.h>
#endif
+#include <net/net_debug.h>
-/* The interface for checksum offload between the stack and networking drivers
+/**
+ * DOC: skb checksums
+ *
+ * The interface for checksum offload between the stack and networking drivers
* is as follows...
*
- * A. IP checksum related features
+ * IP checksum related features
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* Drivers advertise checksum offload capabilities in the features of a device.
* From the stack's point of view these are capabilities offered by the driver.
* A driver typically only advertises features that it is capable of offloading
* to its device.
*
- * The checksum related features are:
- *
- * NETIF_F_HW_CSUM - The driver (or its device) is able to compute one
- * IP (one's complement) checksum for any combination
- * of protocols or protocol layering. The checksum is
- * computed and set in a packet per the CHECKSUM_PARTIAL
- * interface (see below).
- *
- * NETIF_F_IP_CSUM - Driver (device) is only able to checksum plain
- * TCP or UDP packets over IPv4. These are specifically
- * unencapsulated packets of the form IPv4|TCP or
- * IPv4|UDP where the Protocol field in the IPv4 header
- * is TCP or UDP. The IPv4 header may contain IP options.
- * This feature cannot be set in features for a device
- * with NETIF_F_HW_CSUM also set. This feature is being
- * DEPRECATED (see below).
- *
- * NETIF_F_IPV6_CSUM - Driver (device) is only able to checksum plain
- * TCP or UDP packets over IPv6. These are specifically
- * unencapsulated packets of the form IPv6|TCP or
- * IPv6|UDP where the Next Header field in the IPv6
- * header is either TCP or UDP. IPv6 extension headers
- * are not supported with this feature. This feature
- * cannot be set in features for a device with
- * NETIF_F_HW_CSUM also set. This feature is being
- * DEPRECATED (see below).
- *
- * NETIF_F_RXCSUM - Driver (device) performs receive checksum offload.
- * This flag is only used to disable the RX checksum
- * feature for a device. The stack will accept receive
- * checksum indication in packets received on a device
- * regardless of whether NETIF_F_RXCSUM is set.
- *
- * B. Checksumming of received packets by device. Indication of checksum
- * verification is set in skb->ip_summed. Possible values are:
- *
- * CHECKSUM_NONE:
+ * .. flat-table:: Checksum related device features
+ * :widths: 1 10
+ *
+ * * - %NETIF_F_HW_CSUM
+ * - The driver (or its device) is able to compute one
+ * IP (one's complement) checksum for any combination
+ * of protocols or protocol layering. The checksum is
+ * computed and set in a packet per the CHECKSUM_PARTIAL
+ * interface (see below).
+ *
+ * * - %NETIF_F_IP_CSUM
+ * - Driver (device) is only able to checksum plain
+ * TCP or UDP packets over IPv4. These are specifically
+ * unencapsulated packets of the form IPv4|TCP or
+ * IPv4|UDP where the Protocol field in the IPv4 header
+ * is TCP or UDP. The IPv4 header may contain IP options.
+ * This feature cannot be set in features for a device
+ * with NETIF_F_HW_CSUM also set. This feature is being
+ * DEPRECATED (see below).
+ *
+ * * - %NETIF_F_IPV6_CSUM
+ * - Driver (device) is only able to checksum plain
+ * TCP or UDP packets over IPv6. These are specifically
+ * unencapsulated packets of the form IPv6|TCP or
+ * IPv6|UDP where the Next Header field in the IPv6
+ * header is either TCP or UDP. IPv6 extension headers
+ * are not supported with this feature. This feature
+ * cannot be set in features for a device with
+ * NETIF_F_HW_CSUM also set. This feature is being
+ * DEPRECATED (see below).
+ *
+ * * - %NETIF_F_RXCSUM
+ * - Driver (device) performs receive checksum offload.
+ * This flag is only used to disable the RX checksum
+ * feature for a device. The stack will accept receive
+ * checksum indication in packets received on a device
+ * regardless of whether NETIF_F_RXCSUM is set.
+ *
+ * Checksumming of received packets by device
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * Indication of checksum verification is set in &sk_buff.ip_summed.
+ * Possible values are:
+ *
+ * - %CHECKSUM_NONE
*
* Device did not checksum this packet e.g. due to lack of capabilities.
* The packet contains full (though not verified) checksum in packet but
* not in skb->csum. Thus, skb->csum is undefined in this case.
*
- * CHECKSUM_UNNECESSARY:
+ * - %CHECKSUM_UNNECESSARY
*
* The hardware you're dealing with doesn't calculate the full checksum
- * (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums
- * for specific protocols. For such packets it will set CHECKSUM_UNNECESSARY
- * if their checksums are okay. skb->csum is still undefined in this case
+ * (as in %CHECKSUM_COMPLETE), but it does parse headers and verify checksums
+ * for specific protocols. For such packets it will set %CHECKSUM_UNNECESSARY
+ * if their checksums are okay. &sk_buff.csum is still undefined in this case
* though. A driver or device must never modify the checksum field in the
* packet even if checksum is verified.
*
- * CHECKSUM_UNNECESSARY is applicable to following protocols:
- * TCP: IPv6 and IPv4.
- * UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
+ * %CHECKSUM_UNNECESSARY is applicable to following protocols:
+ *
+ * - TCP: IPv6 and IPv4.
+ * - UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
* zero UDP checksum for either IPv4 or IPv6, the networking stack
* may perform further validation in this case.
- * GRE: only if the checksum is present in the header.
- * SCTP: indicates the CRC in SCTP header has been validated.
- * FCOE: indicates the CRC in FC frame has been validated.
+ * - GRE: only if the checksum is present in the header.
+ * - SCTP: indicates the CRC in SCTP header has been validated.
+ * - FCOE: indicates the CRC in FC frame has been validated.
*
- * skb->csum_level indicates the number of consecutive checksums found in
- * the packet minus one that have been verified as CHECKSUM_UNNECESSARY.
+ * &sk_buff.csum_level indicates the number of consecutive checksums found in
+ * the packet minus one that have been verified as %CHECKSUM_UNNECESSARY.
* For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
* and a device is able to verify the checksums for UDP (possibly zero),
- * GRE (checksum flag is set) and TCP, skb->csum_level would be set to
+ * GRE (checksum flag is set) and TCP, &sk_buff.csum_level would be set to
* two. If the device were only able to verify the UDP checksum and not
* GRE, either because it doesn't support GRE checksum or because GRE
* checksum is bad, skb->csum_level would be set to zero (TCP checksum is
* not considered in this case).
*
- * CHECKSUM_COMPLETE:
+ * - %CHECKSUM_COMPLETE
*
* This is the most generic way. The device supplied checksum of the _whole_
- * packet as seen by netif_rx() and fills in skb->csum. This means the
+ * packet as seen by netif_rx() and fills in &sk_buff.csum. This means the
* hardware doesn't need to parse L3/L4 headers to implement this.
*
* Notes:
+ *
* - Even if device supports only some protocols, but is able to produce
* skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
* - CHECKSUM_COMPLETE is not applicable to SCTP and FCoE protocols.
*
- * CHECKSUM_PARTIAL:
+ * - %CHECKSUM_PARTIAL
*
* A checksum is set up to be offloaded to a device as described in the
* output description for CHECKSUM_PARTIAL. This may occur on a packet
@@ -146,14 +161,18 @@
* packet that are after the checksum being offloaded are not considered to
* be verified.
*
- * C. Checksumming on transmit for non-GSO. The stack requests checksum offload
- * in the skb->ip_summed for a packet. Values are:
+ * Checksumming on transmit for non-GSO
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
- * CHECKSUM_PARTIAL:
+ * The stack requests checksum offload in the &sk_buff.ip_summed for a packet.
+ * Values are:
+ *
+ * - %CHECKSUM_PARTIAL
*
* The driver is required to checksum the packet as seen by hard_start_xmit()
- * from skb->csum_start up to the end, and to record/write the checksum at
- * offset skb->csum_start + skb->csum_offset. A driver may verify that the
+ * from &sk_buff.csum_start up to the end, and to record/write the checksum at
+ * offset &sk_buff.csum_start + &sk_buff.csum_offset.
+ * A driver may verify that the
* csum_start and csum_offset values are valid values given the length and
* offset of the packet, but it should not attempt to validate that the
* checksum refers to a legitimate transport layer checksum -- it is the
@@ -165,55 +184,66 @@
* checksum calculation to the device, or call skb_checksum_help (in the case
* that the device does not support offload for a particular checksum).
*
- * NETIF_F_IP_CSUM and NETIF_F_IPV6_CSUM are being deprecated in favor of
- * NETIF_F_HW_CSUM. New devices should use NETIF_F_HW_CSUM to indicate
+ * %NETIF_F_IP_CSUM and %NETIF_F_IPV6_CSUM are being deprecated in favor of
+ * %NETIF_F_HW_CSUM. New devices should use %NETIF_F_HW_CSUM to indicate
* checksum offload capability.
- * skb_csum_hwoffload_help() can be called to resolve CHECKSUM_PARTIAL based
+ * skb_csum_hwoffload_help() can be called to resolve %CHECKSUM_PARTIAL based
* on network device checksumming capabilities: if a packet does not match
- * them, skb_checksum_help or skb_crc32c_help (depending on the value of
- * csum_not_inet, see item D.) is called to resolve the checksum.
+ * them, skb_checksum_help() or skb_crc32c_help() (depending on the value of
+ * &sk_buff.csum_not_inet, see :ref:`crc`)
+ * is called to resolve the checksum.
*
- * CHECKSUM_NONE:
+ * - %CHECKSUM_NONE
*
* The skb was already checksummed by the protocol, or a checksum is not
* required.
*
- * CHECKSUM_UNNECESSARY:
+ * - %CHECKSUM_UNNECESSARY
*
* This has the same meaning as CHECKSUM_NONE for checksum offload on
* output.
*
- * CHECKSUM_COMPLETE:
+ * - %CHECKSUM_COMPLETE
+ *
* Not used in checksum output. If a driver observes a packet with this value
- * set in skbuff, it should treat the packet as if CHECKSUM_NONE were set.
- *
- * D. Non-IP checksum (CRC) offloads
- *
- * NETIF_F_SCTP_CRC - This feature indicates that a device is capable of
- * offloading the SCTP CRC in a packet. To perform this offload the stack
- * will set csum_start and csum_offset accordingly, set ip_summed to
- * CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication in
- * the skbuff that the CHECKSUM_PARTIAL refers to CRC32c.
- * A driver that supports both IP checksum offload and SCTP CRC32c offload
- * must verify which offload is configured for a packet by testing the
- * value of skb->csum_not_inet; skb_crc32c_csum_help is provided to resolve
- * CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1.
- *
- * NETIF_F_FCOE_CRC - This feature indicates that a device is capable of
- * offloading the FCOE CRC in a packet. To perform this offload the stack
- * will set ip_summed to CHECKSUM_PARTIAL and set csum_start and csum_offset
- * accordingly. Note that there is no indication in the skbuff that the
- * CHECKSUM_PARTIAL refers to an FCOE checksum, so a driver that supports
- * both IP checksum offload and FCOE CRC offload must verify which offload
- * is configured for a packet, presumably by inspecting packet headers.
- *
- * E. Checksumming on output with GSO.
- *
- * In the case of a GSO packet (skb_is_gso(skb) is true), checksum offload
+ * set in skbuff, it should treat the packet as if %CHECKSUM_NONE were set.
+ *
+ * .. _crc:
+ *
+ * Non-IP checksum (CRC) offloads
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * .. flat-table::
+ * :widths: 1 10
+ *
+ * * - %NETIF_F_SCTP_CRC
+ * - This feature indicates that a device is capable of
+ * offloading the SCTP CRC in a packet. To perform this offload the stack
+ * will set csum_start and csum_offset accordingly, set ip_summed to
+ * %CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication
+ * in the skbuff that the %CHECKSUM_PARTIAL refers to CRC32c.
+ * A driver that supports both IP checksum offload and SCTP CRC32c offload
+ * must verify which offload is configured for a packet by testing the
+ * value of &sk_buff.csum_not_inet; skb_crc32c_csum_help() is provided to
+ * resolve %CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1.
+ *
+ * * - %NETIF_F_FCOE_CRC
+ * - This feature indicates that a device is capable of offloading the FCOE
+ * CRC in a packet. To perform this offload the stack will set ip_summed
+ * to %CHECKSUM_PARTIAL and set csum_start and csum_offset
+ * accordingly. Note that there is no indication in the skbuff that the
+ * %CHECKSUM_PARTIAL refers to an FCOE checksum, so a driver that supports
+ * both IP checksum offload and FCOE CRC offload must verify which offload
+ * is configured for a packet, presumably by inspecting packet headers.
+ *
+ * Checksumming on output with GSO
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * In the case of a GSO packet (skb_is_gso() is true), checksum offload
* is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the
- * gso_type is SKB_GSO_TCPV4 or SKB_GSO_TCPV6, TCP checksum offload as
+ * gso_type is %SKB_GSO_TCPV4 or %SKB_GSO_TCPV6, TCP checksum offload as
* part of the GSO operation is implied. If a checksum is being offloaded
- * with GSO then ip_summed is CHECKSUM_PARTIAL, and both csum_start and
+ * with GSO then ip_summed is %CHECKSUM_PARTIAL, and both csum_start and
* csum_offset are set to refer to the outermost checksum being offloaded
* (two offloaded checksums are possible with UDP encapsulation).
*/
@@ -381,6 +411,19 @@ enum skb_drop_reason {
* the ofo queue, corresponding to
* LINUX_MIB_TCPOFOMERGE
*/
+ SKB_DROP_REASON_TCP_RFC7323_PAWS, /* PAWS check, corresponding to
+ * LINUX_MIB_PAWSESTABREJECTED
+ */
+ SKB_DROP_REASON_TCP_INVALID_SEQUENCE, /* Not acceptable SEQ field */
+ SKB_DROP_REASON_TCP_RESET, /* Invalid RST packet */
+ SKB_DROP_REASON_TCP_INVALID_SYN, /* Incoming packet has unexpected SYN flag */
+ SKB_DROP_REASON_TCP_CLOSE, /* TCP socket in CLOSE state */
+ SKB_DROP_REASON_TCP_FASTOPEN, /* dropped by FASTOPEN request socket */
+ SKB_DROP_REASON_TCP_OLD_ACK, /* TCP ACK is old, but in window */
+ SKB_DROP_REASON_TCP_TOO_OLD_ACK, /* TCP ACK is too old */
+ SKB_DROP_REASON_TCP_ACK_UNSENT_DATA, /* TCP ACK for data we haven't sent yet */
+ SKB_DROP_REASON_TCP_OFO_QUEUE_PRUNE, /* pruned from TCP OFO queue */
+ SKB_DROP_REASON_TCP_OFO_DROP, /* data already in receive queue */
SKB_DROP_REASON_IP_OUTNOROUTES, /* route lookup failed */
SKB_DROP_REASON_BPF_CGROUP_EGRESS, /* dropped by
* BPF_PROG_TYPE_CGROUP_SKB
@@ -408,11 +451,9 @@ enum skb_drop_reason {
*/
SKB_DROP_REASON_XDP, /* dropped by XDP in input path */
SKB_DROP_REASON_TC_INGRESS, /* dropped in TC ingress HOOK */
- SKB_DROP_REASON_PTYPE_ABSENT, /* not packet_type found to handle
- * the skb. For an etner packet,
- * this means that L3 protocol is
- * not supported
- */
+ SKB_DROP_REASON_UNHANDLED_PROTO, /* protocol not implemented
+ * or not supported
+ */
SKB_DROP_REASON_SKB_CSUM, /* sk_buff checksum computation
* error
*/
@@ -444,9 +485,36 @@ enum skb_drop_reason {
SKB_DROP_REASON_TAP_TXFILTER, /* dropped by tx filter implemented
* at tun/tap, e.g., check_filter()
*/
+ SKB_DROP_REASON_ICMP_CSUM, /* ICMP checksum error */
+ SKB_DROP_REASON_INVALID_PROTO, /* the packet doesn't follow RFC
+ * 2211, such as a broadcasts
+ * ICMP_TIMESTAMP
+ */
+ SKB_DROP_REASON_IP_INADDRERRORS, /* host unreachable, corresponding
+ * to IPSTATS_MIB_INADDRERRORS
+ */
+ SKB_DROP_REASON_IP_INNOROUTES, /* network unreachable, corresponding
+ * to IPSTATS_MIB_INADDRERRORS
+ */
+ SKB_DROP_REASON_PKT_TOO_BIG, /* packet size is too big (maybe exceed
+ * the MTU)
+ */
SKB_DROP_REASON_MAX,
};
+#define SKB_DR_INIT(name, reason) \
+ enum skb_drop_reason name = SKB_DROP_REASON_##reason
+#define SKB_DR(name) \
+ SKB_DR_INIT(name, NOT_SPECIFIED)
+#define SKB_DR_SET(name, reason) \
+ (name = SKB_DROP_REASON_##reason)
+#define SKB_DR_OR(name, reason) \
+ do { \
+ if (name == SKB_DROP_REASON_NOT_SPECIFIED || \
+ name == SKB_NOT_DROPPED_YET) \
+ SKB_DR_SET(name, reason); \
+ } while (0)
+
/* To allow 64K frame to be packed as single skb without frag_list we
* require 64K/PAGE_SIZE pages plus 1 additional page to allow for
* buffers which do not start on a page boundary.
@@ -551,8 +619,10 @@ static inline bool skb_frag_must_loop(struct page *p)
/**
* struct skb_shared_hwtstamps - hardware time stamps
- * @hwtstamp: hardware time stamp transformed into duration
- * since arbitrary point in time
+ * @hwtstamp: hardware time stamp transformed into duration
+ * since arbitrary point in time
+ * @netdev_data: address/cookie of network device driver used as
+ * reference to actual hardware time stamp
*
* Software time stamps generated by ktime_get_real() are stored in
* skb->tstamp.
@@ -564,7 +634,10 @@ static inline bool skb_frag_must_loop(struct page *p)
* &skb_shared_info. Use skb_hwtstamps() to get a pointer.
*/
struct skb_shared_hwtstamps {
- ktime_t hwtstamp;
+ union {
+ ktime_t hwtstamp;
+ void *netdev_data;
+ };
};
/* Definitions for tx_flags in struct skb_shared_info */
@@ -578,16 +651,24 @@ enum {
/* device driver is going to provide hardware time stamp */
SKBTX_IN_PROGRESS = 1 << 2,
+ /* generate hardware time stamp based on cycles if supported */
+ SKBTX_HW_TSTAMP_USE_CYCLES = 1 << 3,
+
/* generate wifi status information (where possible) */
SKBTX_WIFI_STATUS = 1 << 4,
+ /* determine hardware time stamp based on time or cycles */
+ SKBTX_HW_TSTAMP_NETDEV = 1 << 5,
+
/* generate software time stamp when entering packet scheduling */
SKBTX_SCHED_TSTAMP = 1 << 6,
};
#define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
SKBTX_SCHED_TSTAMP)
-#define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP)
+#define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | \
+ SKBTX_HW_TSTAMP_USE_CYCLES | \
+ SKBTX_ANY_SW_TSTAMP)
/* Definitions for flags in struct skb_shared_info */
enum {
@@ -647,20 +728,6 @@ struct ubuf_info {
int mm_account_pinned_pages(struct mmpin *mmp, size_t size);
void mm_unaccount_pinned_pages(struct mmpin *mmp);
-struct ubuf_info *msg_zerocopy_alloc(struct sock *sk, size_t size);
-struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size,
- struct ubuf_info *uarg);
-
-void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref);
-
-void msg_zerocopy_callback(struct sk_buff *skb, struct ubuf_info *uarg,
- bool success);
-
-int skb_zerocopy_iter_dgram(struct sk_buff *skb, struct msghdr *msg, int len);
-int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb,
- struct msghdr *msg, int len,
- struct ubuf_info *uarg);
-
/* This data is invariant across clones and lives at
* the end of the header data, ie. at skb->end.
*/
@@ -691,16 +758,32 @@ struct skb_shared_info {
skb_frag_t frags[MAX_SKB_FRAGS];
};
-/* We divide dataref into two halves. The higher 16 bits hold references
- * to the payload part of skb->data. The lower 16 bits hold references to
- * the entire skb->data. A clone of a headerless skb holds the length of
- * the header in skb->hdr_len.
- *
- * All users must obey the rule that the skb->data reference count must be
- * greater than or equal to the payload reference count.
- *
- * Holding a reference to the payload part means that the user does not
- * care about modifications to the header part of skb->data.
+/**
+ * DOC: dataref and headerless skbs
+ *
+ * Transport layers send out clones of payload skbs they hold for
+ * retransmissions. To allow lower layers of the stack to prepend their headers
+ * we split &skb_shared_info.dataref into two halves.
+ * The lower 16 bits count the overall number of references.
+ * The higher 16 bits indicate how many of the references are payload-only.
+ * skb_header_cloned() checks if skb is allowed to add / write the headers.
+ *
+ * The creator of the skb (e.g. TCP) marks its skb as &sk_buff.nohdr
+ * (via __skb_header_release()). Any clone created from marked skb will get
+ * &sk_buff.hdr_len populated with the available headroom.
+ * If there's the only clone in existence it's able to modify the headroom
+ * at will. The sequence of calls inside the transport layer is::
+ *
+ * <alloc skb>
+ * skb_reserve()
+ * __skb_header_release()
+ * skb_clone()
+ * // send the clone down the stack
+ *
+ * This is not a very generic construct and it depends on the transport layers
+ * doing the right thing. In practice there's usually only one payload-only skb.
+ * Having multiple payload-only skbs with different lengths of hdr_len is not
+ * possible. The payload-only skbs should never leave their owner.
*/
#define SKB_DATAREF_SHIFT 16
#define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
@@ -765,6 +848,46 @@ typedef unsigned char *sk_buff_data_t;
#endif
/**
+ * DOC: Basic sk_buff geometry
+ *
+ * struct sk_buff itself is a metadata structure and does not hold any packet
+ * data. All the data is held in associated buffers.
+ *
+ * &sk_buff.head points to the main "head" buffer. The head buffer is divided
+ * into two parts:
+ *
+ * - data buffer, containing headers and sometimes payload;
+ * this is the part of the skb operated on by the common helpers
+ * such as skb_put() or skb_pull();
+ * - shared info (struct skb_shared_info) which holds an array of pointers
+ * to read-only data in the (page, offset, length) format.
+ *
+ * Optionally &skb_shared_info.frag_list may point to another skb.
+ *
+ * Basic diagram may look like this::
+ *
+ * ---------------
+ * | sk_buff |
+ * ---------------
+ * ,--------------------------- + head
+ * / ,----------------- + data
+ * / / ,----------- + tail
+ * | | | , + end
+ * | | | |
+ * v v v v
+ * -----------------------------------------------
+ * | headroom | data | tailroom | skb_shared_info |
+ * -----------------------------------------------
+ * + [page frag]
+ * + [page frag]
+ * + [page frag]
+ * + [page frag] ---------
+ * + frag_list --> | sk_buff |
+ * ---------
+ *
+ */
+
+/**
* struct sk_buff - socket buffer
* @next: Next buffer in list
* @prev: Previous buffer in list
@@ -851,6 +974,7 @@ typedef unsigned char *sk_buff_data_t;
* delivery_time at egress.
* @napi_id: id of the NAPI struct this skb came from
* @sender_cpu: (aka @napi_id) source CPU in XPS
+ * @alloc_cpu: CPU which did the skb allocation.
* @secmark: security marking
* @mark: Generic packet mark
* @reserved_tailroom: (aka @mark) number of bytes of free space available
@@ -1043,6 +1167,7 @@ struct sk_buff {
unsigned int sender_cpu;
};
#endif
+ u16 alloc_cpu;
#ifdef CONFIG_NETWORK_SECMARK
__u32 secmark;
#endif
@@ -1284,6 +1409,7 @@ struct sk_buff *__build_skb(void *data, unsigned int frag_size);
struct sk_buff *build_skb(void *data, unsigned int frag_size);
struct sk_buff *build_skb_around(struct sk_buff *skb,
void *data, unsigned int frag_size);
+void skb_attempt_defer_free(struct sk_buff *skb);
struct sk_buff *napi_build_skb(void *data, unsigned int frag_size);
@@ -1639,6 +1765,27 @@ static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset)
}
#endif
+struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size,
+ struct ubuf_info *uarg);
+
+void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref);
+
+void msg_zerocopy_callback(struct sk_buff *skb, struct ubuf_info *uarg,
+ bool success);
+
+int __zerocopy_sg_from_iter(struct sock *sk, struct sk_buff *skb,
+ struct iov_iter *from, size_t length);
+
+static inline int skb_zerocopy_iter_dgram(struct sk_buff *skb,
+ struct msghdr *msg, int len)
+{
+ return __zerocopy_sg_from_iter(skb->sk, skb, &msg->msg_iter, len);
+}
+
+int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb,
+ struct msghdr *msg, int len,
+ struct ubuf_info *uarg);
+
/* Internal */
#define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
@@ -1922,8 +2069,10 @@ static inline int skb_header_unclone(struct sk_buff *skb, gfp_t pri)
}
/**
- * __skb_header_release - release reference to header
- * @skb: buffer to operate on
+ * __skb_header_release() - allow clones to use the headroom
+ * @skb: buffer to operate on
+ *
+ * See "DOC: dataref and headerless skbs".
*/
static inline void __skb_header_release(struct sk_buff *skb)
{
@@ -2752,6 +2901,7 @@ static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
{
+ DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb));
return skb->head + skb->transport_header;
}
@@ -3836,8 +3986,7 @@ struct sk_buff *__skb_try_recv_datagram(struct sock *sk,
struct sk_buff *__skb_recv_datagram(struct sock *sk,
struct sk_buff_head *sk_queue,
unsigned int flags, int *off, int *err);
-struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, int noblock,
- int *err);
+struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned int flags, int *err);
__poll_t datagram_poll(struct file *file, struct socket *sock,
struct poll_table_struct *wait);
int skb_copy_datagram_iter(const struct sk_buff *from, int offset,
@@ -3886,7 +4035,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
struct sk_buff *skb_segment_list(struct sk_buff *skb, netdev_features_t features,
unsigned int offset);
struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
-int skb_ensure_writable(struct sk_buff *skb, int write_len);
+int skb_ensure_writable(struct sk_buff *skb, unsigned int write_len);
int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci);
int skb_vlan_pop(struct sk_buff *skb);
int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci);
@@ -4895,9 +5044,7 @@ static inline void skb_forward_csum(struct sk_buff *skb)
*/
static inline void skb_checksum_none_assert(const struct sk_buff *skb)
{
-#ifdef DEBUG
- BUG_ON(skb->ip_summed != CHECKSUM_NONE);
-#endif
+ DEBUG_NET_WARN_ON_ONCE(skb->ip_summed != CHECKSUM_NONE);
}
bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);