LC_HASHTOADDR(3)

💖 LC_HASHTOADDR(3) 💖

okay so bestie, we're in the Librecast Programmer's Manual today and the page we're reading is lc_hashtoaddr — and ngl it's a little one but she's important, so let's get into it ✨

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🌸 NAME 🌸

lc_hashtoaddr — create IPv6 multicast addr from supplied hash and flags

like. it literally does what it says on the tin. a hash goes in, an address comes out. the way that she's just a converter and she's still the moment?? 💅

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📚 LIBRARY 📚

Librecast library (liblibrecast, -llibrecast)

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🎀 SYNOPSIS 🎀

#include <librecast/net.h>

void lc_hashtoaddr(struct in6_addr *addr, unsigned char *hash, size_t hashlen,
                   unsigned char flags);

Compile and link with -llibrecast. 🫶

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✨ DESCRIPTION ✨

so the lc_hashtoaddr() function creates and returns an IPv6 multicast address in addr, built from the supplied hash of length hashlen plus your flags. it's giving assembly line but make it networking 💖

the address that lands back in addr is a valid IPv6 multicast address. here's the breakdown, no cap:

• the first 8 bits are set to 1 ⭐
• the following 8 bits are set to flags — and lowkey important: this should be the valid IPv6 multicast 4-bit flags field as defined in IETF RFC 4291, followed by the 4 bits for multicast scope 👑
• the first 14 bytes of hash are used for the remaining 14 bytes of the address 🦋

so yeah, 14 + 2 = 16 bytes, a whole IPv6 address, slay 🎀

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🫧 RETURN VALUE 🫧

the lc_hashtoaddr () function returns no value. it's a void girlie. she does the work and says nothing. iconic, honestly 💅

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💀 ERRORS 💀

None. not a single one. she simply does not miss ✨

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🔥 SEE ALSO 🔥

• lc_channel_new(3)
• lc_channel_close(3)
• lc_ctx_new(3)
• lc_socket_new(3)
• lc_channel_new(3)

(yes bestie, lc_channel_new(3) is listed twice in the original and I am not the one who's gonna touch that. we respect the source material fr fr 🙈💜)

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and that's the whole page! short, sweet, absolutely ate. go build some multicast addresses and be the main character of your own network 🌈

LIBRECAST · 2023-07-23 · LC_HASHTOADDR(3) — mwah, love u, bye 🎀💖✨