skb_copy_expand – copy and expand sk_buff Synopsis struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom, int newtailroom, gfp_t gfp_mask); Arguments skb buffer to copy newheadroom new free bytes at head newtailroom new free bytes at tail gfp_mask allocation priority Description Make a copy of both an sk_buff and its data and while doing so allocate…
skb_copy_datagram_iter – Copy a datagram to an iovec iterator. Synopsis int skb_copy_datagram_iter(const struct sk_buff *skb, int offset, struct iov_iter *to, int len); Arguments skb buffer to copy offset offset in the buffer to start copying from to iovec iterator to copy to len amount of data to copy from buffer to iovec Copyright
skb_copy_datagram_from_iter – Copy a datagram from an iov_iter. Synopsis int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset, struct iov_iter *from, int len); Arguments skb buffer to copy offset offset in the buffer to start copying to from the copy source len amount of data to copy to buffer from iovec Description Returns 0 or -EFAULT. Copyright
skb_copy_bits – copy bits from skb to kernel buffer Synopsis int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len); Arguments skb source skb offset offset in source to destination buffer len number of bytes to copy Description Copy the specified number of bytes from the source skb to the destination buffer. CAUTION !…
skb_copy_and_csum_datagram_msg – Copy and checksum skb to user iovec. Synopsis int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen, struct msghdr *msg); Arguments skb skbuff hlen hardware length msg destination Description Caller _must_ check that skb will fit to this iovec. Return 0 – success. -EINVAL – checksum failure. -EFAULT – fault during copy. Copyright
skb_copy – create private copy of an sk_buff Synopsis struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask); Arguments skb buffer to copy gfp_mask allocation priority Description Make a copy of both an sk_buff and its data. This is used when the caller wishes to modify the data and needs a private copy of the data…
skb_cloned – is the buffer a clone Synopsis int skb_cloned(const struct sk_buff *skb); Arguments skb buffer to check Description Returns true if the buffer was generated with skb_clone and is one of multiple shared copies of the buffer. Cloned buffers are shared data so must not be written to under normal circumstances. Copyright
skb_clone_writable – is the header of a clone writable Synopsis int skb_clone_writable(const struct sk_buff *skb, unsigned int len); Arguments skb buffer to check len length up to which to write Description Returns true if modifying the header part of the cloned buffer does not requires the data to be copied. Copyright
skb_clone_sk – create clone of skb, and take reference to socket Synopsis struct sk_buff *skb_clone_sk(struct sk_buff *skb); Arguments skb the skb to clone Description This function creates a clone of a buffer that holds a reference on sk_refcnt. Buffers created via this function are meant to be returned using sock_queue_err_skb, or free via kfree_skb. When…
skb_clone – duplicate an sk_buff Synopsis struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask); Arguments skb buffer to clone gfp_mask allocation priority Description Duplicate an sk_buff. The new one is not owned by a socket. Both copies share the same packet data but not structure. The new buffer has a reference count of 1. If the…
skb_checksum_trimmed – validate checksum of an skb Synopsis struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb, unsigned int transport_len, __sum16 (*skb_chkf)(struct sk_buff *skb)); Arguments skb the skb to check transport_len the data length beyond the network header skb_chkf checksum function to use Description Applies the given checksum function skb_chkf to the provided skb. Returns a checked and maybe…
skb_checksum_setup – set up partial checksum offset Synopsis int skb_checksum_setup(struct sk_buff *skb, bool recalculate); Arguments skb the skb to set up recalculate if true the pseudo-header checksum will be recalculated Copyright
skb_checksum_none_assert – make sure skb ip_summed is CHECKSUM_NONE Synopsis void skb_checksum_none_assert(const struct sk_buff *skb); Arguments skb skb to check Description fresh skbs have their ip_summed set to CHECKSUM_NONE. Instead of forcing ip_summed to CHECKSUM_NONE, we can use this helper, to document places where we make this assertion. Copyright
skb_checksum_complete – Calculate checksum of an entire packet Synopsis __sum16 skb_checksum_complete(struct sk_buff * skb); Arguments skb packet to process Description This function calculates the checksum over the entire packet plus the value of skb->csum. The latter can be used to supply the checksum of a pseudo header as used by TCP/UDP. It returns the checksum. For protocols…
skb_availroom – bytes at buffer end Synopsis int skb_availroom(const struct sk_buff *skb); Arguments skb buffer to check Description Return the number of bytes of free space at the tail of an sk_buff allocated by sk_stream_alloc Copyright
skb_append_datato_frags – append the user data to a skb Synopsis int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb, int (*getfrag)(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb), void *from, int length); Arguments sk sock structure skb skb structure to be appended with user data. getfrag call back function to be used…
skb_append – append a buffer Synopsis void skb_append(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list); Arguments old buffer to insert after newsk buffer to insert list list to use Description Place a packet after a given packet in a list. The list locks are taken and this function is atomic with respect to other…
skb_abort_seq_read – Abort a sequential read of skb data Synopsis void skb_abort_seq_read(struct skb_seq_state *st); Arguments st state variable Description Must be called if skb_seq_read was not called until it returned 0. Copyright
sk_wmem_alloc_get – returns write allocations Synopsis int sk_wmem_alloc_get(const struct sock *sk); Arguments sk socket Description Returns sk_wmem_alloc minus initial offset of one Copyright
sk_wait_data – wait for data to arrive at sk_receive_queue Synopsis int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb); Arguments sk sock to wait on timeo for how long skb last skb seen on sk_receive_queue Description Now socket state including sk->sk_err is changed only under lock, hence we may omit checks after joining wait…