kernel_sendmsg(9)

💌 kernel_sendmsg(9) — straight out of the Kernel API Manual, bestie

okay so picture this: you're deep in kernel space, you've got a socket, and you need to send a message through it. that's it. that's the whole vibe. this page is your group chat tutorial for it 💅

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✨ NAME ✨

kernel_sendmsg — send a message through @sock (kernel-space, no cap)

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🦋 SYNOPSIS 🦋

int kernel_sendmsg (struct socket *sock , struct msghdr *msg , struct
       kvec *vec , size_t num , size_t size );

like, yes, the line breaks are a little chaotic, she's doing her best 🫶

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🎀 ARGUMENTS 🎀

• sock — the socket. your main character. the thing the message goes through 💖
• msg — the message header. the ✨metadata moment✨
• vec — kernel vec. the actual chunks of message data live here
• num — vec array length. how many entries in vec you're working with
• size — total message data size. the full byte count of the message, not a guess, the real number 🍓

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👑 DESCRIPTION 👑

so here's what goes down: it builds the message data with vec and sends it through sock. that's the whole plot, no twist ending.

it returns the number of bytes sent — or an error code 😭 so like, check the return value, bestie, don't just assume it slayed.

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🌈 SEE ALSO 🌈

the kernel file ./net/socket.c, plus this whole iconic friend group:

• move_addr_to_kernel(9)
• move_addr_to_user(9)
• sock_read_xattr(9)
• sock_alloc_file(9)
• sock_from_file(9)
• sockfd_lookup(9)
• sock_alloc(9)
• sock_release(9)
• sock_sendmsg(9)
• sock_recvmsg(9)
• kernel_recvmsg(9)
• sock_create_lite(9)
• __sock_create(9)
• sock_create(9)
• sock_create_kern(9)
• sock_register(9)
• sock_unregister(9)
• kernel_bind(9)
• kernel_listen(9)
• kernel_accept(9)
• kernel_connect(9)
• kernel_getsockname(9)
• kernel_getpeername(9)
• kernel_sock_shutdown(9)
• kernel_sock_ip_overhead(9)

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💫 the sign-off 💫

this lil masterpiece lives under ./net, dated October 2026, and she answers to kernel_sendmsg(9). mwah 💋 go send a message fr fr 🧚‍♀️✨