CODEWITHSUNDEEP
cnetwork-programminglinux-kernel
user138645
user138645

Reputation: 782

Control TCP header fields from a user program

Is it possible to set the fields of a TCP header from a user program? The man page for tcp(7) does not list any fields which can be controlled using setsockopt(2). For IP, we can control the MTU, TTL fields using the setsockopt(2).

int sockfd = socket (AF_INET, SOCK_STREAM, 0);

/* set the TCP fields now */
...
...

Upvotes: 3

Views: 351

Answers (1)

Pradheep
Pradheep

Reputation: 3819

Yes you can use raw sockets to set the TCP/UDP headers from a user program

int fd = socket (PF_INET, SOCK_RAW, IPPROTO_TCP);

More info on the link http://csis.bits-pilani.ac.in/faculty/dk_tyagi/Study_stuffs/raw.html

Search for RAW sockets and you will find more

One more good reference is the Unix network programming by Richard stevenson

Upvotes: 4

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