STRUCT SSH_PACKET(9)

💖 struct ssh_packet(9) 💖

okay so bestie, welcome to the Kernel API Manual ✨ — today's main character is struct ssh_packet, which is, and I cannot stress this enough, the SSH transport packet. periodt. 🎀

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✨ NAME ✨

struct ssh_packet — SSH transport packet. that's it, that's the vibe 🦋

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🌸 SYNOPSIS 🌸

struct ssh_packet {
    struct ssh_ptl *ptl;
    struct kref refcnt;
    u8 priority;
    struct {
      size_t len;
      u8 *ptr;
    } data;
    unsigned long state;
    ktime_t timestamp;
    struct list_head queue_node;
    struct list_head pending_node;
    const struct ssh_packet_ops *ops;
 };

like… look at her. iconic structure. no notes. 👑

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🫶 Members 🫶

okay so let's go through the whole squad, member by member, no skips:

• ptl — pointer to the packet transport layer 💅. this one may be NULL if the packet (or the enclosing request) hasn't been submitted yet. so like, she's not committed yet. relatable.
• refcnt — the reference count of the packet. keep track of who's holding on, bestie 🧵.
• priority — priority of the packet. it must be computed via SSH_PACKET_PRIORITY, no freestyling 🔥. and lowkey important: it must only be accessed while holding the queue lock, and only after first submission. iykyk.
• data — the raw message data. the actual content, the substance, the moment 💫.
  • data.len — length of the raw message data. how much data we're working with 📏.
  • data.ptr — pointer to the raw message data buffer. the address, the location, the spot 🎯.
• state — state and type flags describing the current packet state (that part's dynamic, it moves) and type (that part's static, she's set in stone) 🌈. see enum ssh_packet_flags for the possible options.
• timestamp — a ktime_t timestamp saying when the latest transmission of a currently pending packet got started ⏰. it may be KTIME_MAX before, or in-between, transmission attempts. this is literally what the packet timeout implementation runs on. and — heads up — it must only be accessed while holding the pending lock, and only after first submission. same rule as priority, fr fr.
• queue_node — the list node for the packet queue. the little link in the chain 🍓.
• pending_node — the list node for the set of pending packets. our girl is pending 💀.
• ops — packet operations. the behavior pack, the whole personality 🎀.

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👑 SEE ALSO 👑

go read these next, bestie, they're all connected (main character energy throughout):

• kernel file ./include/linux/surface_aggregator/serial_hub.h
• enum ssh_frame_type(9)
• struct ssh_frame(9)
• enum ssh_payload_type(9)
• struct ssh_command(9)
• SSH_MESSAGE_LENGTH(9)
• SSH_COMMAND_MESSAGE_LENGTH(9)
• SSH_MSGOFFSET_FRAME(9)
• SSH_MSGOFFSET_COMMAND(9)
• ssh_crc(9)
• ssh_rqid_next_valid(9)
• ssh_rqid_to_event(9)
• ssh_rqid_is_event(9)
• ssh_tc_to_rqid(9)
• ssh_tid_to_index(9)
• ssh_tid_is_valid(9)
• struct ssam_span(9)
• enum ssam_ssh_tid(9)
• enum ssh_packet_base_priority(9)
• SSH_PACKET_PRIORITY(9)
• ssh_packet_priority_get_try(9)
• ssh_packet_priority_get_base(9)
• struct ssh_packet_ops(9)
• ssh_packet_set_data(9)
• struct ssh_request_ops(9)
• struct ssh_request(9)
• to_ssh_request(9)
• ssh_request_get(9)
• ssh_request_put(9)
• ssh_request_set_data(9)

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🫶 quick vibe check reminder: that priority and timestamp lock rule is not a suggestion, bestie. queue lock for priority, pending lock for timestamp, and only after first submission. don't test her. 💅

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aaand that's the whole page, we ate and left no crumbs 🍓✨ this one lives over at ./include/linux/surface_aggreg..., dated October 2026, and it's filed under struct ssh_packet(9) — mwah, bye bestie! 💜🌈🎀