/g/ - syscall of the day: get/setsockopt - Technology

Anonymous

syscall of the day: get/setsoc(...) 02/21/26(Sat)12:52:12 No.108205379

File: Tumblr_l_7248010071817.jpg (256 KB, 835x1149)

syscall of the day: get/setsockopt Anonymous 02/21/26(Sat)12:52:12 No.108205379 Archived

previous: >>108196251
#define __NR_setsockopt            54
#define __NR_getsockopt            55
https://man7.org/linux/man-pages/man2/getsockopt.2.html
https://man7.org/linux/man-pages/man7/socket.7.html
https://man7.org/linux/man-pages/man7/ip.7.html
https://man7.org/linux/man-pages/man7/ipv6.7.html
https://man7.org/linux/man-pages/man7/unix.7.html
https://man7.org/linux/man-pages/man7/ddp.7.html
https://man7.org/linux/man-pages/man7/packet.7.html
https://man7.org/linux/man-pages/man7/x25.7.html
https://man7.org/linux/man-pages/man7/netlink.7.html

the final day of sockets (for a while, at least. not sure if there are any more in the future)
thank GOD. so tired of these...
anyway, here's your fcntl, bro
as a heads up, tomorrow's syscall should be really really cool, so keep an eye out

relevant resources:
man man
man syscalls
https://man7.org/linux/man-pages/
https://linux.die.net/man/
https://elixir.bootlin.com/linux/
https://elixir.bootlin.com/musl/
https://elixir.bootlin.com/glibc/

Anonymous
02/21/26(Sat)13:56:30 No.108205795

Anonymous 02/21/26(Sat)13:56:30 No.108205795

well, at least it's the weekend today, so i can b*mp

Anonymous
02/21/26(Sat)14:55:27 No.108206132

Anonymous 02/21/26(Sat)14:55:27 No.108206132

>>108205379
Everybody who writes C probably used getsockopt at some point, but probably nobody bothered looking into its inner workings, but to be honest, it doesn't seem to interesting to learn more about it than just that which is needed to program with it.

>as a heads up, tomorrow's syscall should be really really cool, so keep an eye out
Sure, looking forward to it. Pinky-finger promise that I won't look it up.

Anonymous
02/21/26(Sat)15:39:06 No.108206410

Anonymous 02/21/26(Sat)15:39:06 No.108206410

heh, that's a whole lotta manpages

>>108206132
I haven't even used sockets in ages, I just do very little network programming.
>Pinky-finger promise that I won't look it up.
I really, really want to look, lol

Anonymous
02/21/26(Sat)17:03:38 No.108206912

Anonymous 02/21/26(Sat)17:03:38 No.108206912

>>108206132
>but probably nobody bothered looking into its inner workings
Most people don’t know how to read the fucking source.

Anonymous
02/21/26(Sat)17:09:33 No.108206935

Anonymous 02/21/26(Sat)17:09:33 No.108206935

>>108205379
Every platform interface should have functions like these that let you enable additional features / extensions or tweak stuff. You get kTLS, UDP offloading, packet filtering, TCP fast open, a huge amount of tweakables through setsockopt, and none of these cause ABI breakages since no new syscalls are added for any of those. I wish the manpages were better on some of the extensions though.

Anonymous
02/21/26(Sat)19:42:31 No.108207831

Anonymous 02/21/26(Sat)19:42:31 No.108207831

bampu

Anonymous
02/22/26(Sun)04:54:57 No.108210429

Anonymous 02/22/26(Sun)04:54:57 No.108210429

>SO_BSDCOMPAT
>Enable BSD bug-to-bug compatibility. This is used by the UDP protocol module in Linux 2.0 and 2.2. If enabled, ICMP errors received for a UDP socket will not be passed to the user program. In later kernel versions, support for this option has been phased out: Linux 2.4 silently ignores it, and Linux 2.6 generates a kernel warning (printk()) if a program uses this option. Linux 2.0 also enabled BSD bug- to-bug compatibility options (random header changing, skipping of the broadcast flag) for raw sockets with this option, but that was removed in Linux 2.2.
Neat