The Linux Manuals (man pages) document is an important part of Linux documents. Linux Manuals are organized as several sections. Each section has a group of commands for a specific area in Linux usage, administration or development.
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…
sk_stream_wait_memory – Wait for more memory for a socket Synopsis int sk_stream_wait_memory(struct sock *sk, long *timeo_p); Arguments sk socket to wait for memory timeo_p for how long Copyright
sk_stream_wait_connect – Wait for a socket to get into the connected state Synopsis int sk_stream_wait_connect(struct sock *sk, long *timeo_p); Arguments sk sock to wait on timeo_p for how long to wait Description Must be called with the socket locked. Copyright
sk_state_store – update sk->sk_state Synopsis void sk_state_store(struct sock *sk, int newstate); Arguments sk socket pointer newstate new state Description Paired with sk_state_load. Should be used in contexts where state change might impact lockless readers. Copyright
sk_state_load – read sk->sk_state for lockless contexts Synopsis int sk_state_load(const struct sock *sk); Arguments sk socket pointer Description Paired with sk_state_store. Used in places we do not hold socket lock : tcp_diag_get_info, tcp_get_info, tcp_poll, get_tcp4_sock … Copyright
sk_set_memalloc – sets SOCK_MEMALLOC Synopsis void sk_set_memalloc(struct sock *sk); Arguments sk socket to set it on Description Set SOCK_MEMALLOC on a socket for access to emergency reserves. It’s the responsibility of the admin to adjust min_free_kbytes to meet the requirements Copyright
sk_rmem_alloc_get – returns read allocations Synopsis int sk_rmem_alloc_get(const struct sock *sk); Arguments sk socket Description Returns sk_rmem_alloc Copyright
sk_page_frag – return an appropriate page_frag Synopsis struct page_frag *sk_page_frag(struct sock *sk); Arguments sk socket Description If socket allocation mode allows current thread to sleep, it means its safe to use the per task page_frag instead of the per socket one. Copyright
sk_ns_capable – General socket capability test Synopsis bool sk_ns_capable(const struct sock * sk, struct user_namespace * user_ns, int cap); Arguments sk Socket to use a capability on or through user_ns The user namespace of the capability to use cap The capability to use Description Test to see if the opener of the socket had when the socket was created and…
sk_net_capable – Network namespace socket capability test Synopsis bool sk_net_capable(const struct sock * sk, int cap); Arguments sk Socket to use a capability on or through cap The capability to use Description Test to see if the opener of the socket had when the socket was created and the current process has the capability cap over the network…
sk_has_allocations – check if allocations are outstanding Synopsis bool sk_has_allocations(const struct sock * sk); Arguments sk socket Description Returns true if socket has write or read allocations Copyright
sk_for_each_entry_offset_rcu – iterate over a list at a given struct offset Synopsis sk_for_each_entry_offset_rcu(tpos, pos, head, offset); Arguments tpos the type * to use as a loop cursor. pos the struct hlist_node to use as a loop cursor. head the head for your list. offset offset of hlist_node within the struct. Copyright
sk_filter_trim_cap – run a packet through a socket filter Synopsis int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap); Arguments sk sock associated with sk_buff skb buffer to filter cap limit on how short the eBPF program may trim the packet Description Run the eBPF program and then cut skb->data to correct size returned…