TCP: Add Linux kernel-based random number generator #7
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Previous generator may not work correctly, so replaced it with kernel random number source devices
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Since it is specific to Linux, you shall use conditional build for such modifications. That is, add |
Because the modification is only availible on Linux
| @@ -1,7 +1,9 @@ | |||
| #include <errno.h> | |||
| #include <fcntl.h> | |||
| #include <linux/random.h> | |||
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Also, use clang-format -i to indent.
src/tcp.c
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| @@ -246,8 +251,14 @@ static int tcp_fsm(struct tcp_conn_tcb *conn, | |||
| } | |||
| rs->tcp_flags |= TCP_ACK; | |||
| rs->tcp_ack_num = rs->tcp_seqno + 1; | |||
| srand(time(NULL)); | |||
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srand(time(NULL)); was the seed of rand()%100;, and I replaced both lines with kernel random number source device.
So srand is no longer needed.
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You have to take care of both POSIX (generic) and Linux kernel random number generator.
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Do you mean that using srand (previous generator) while the environment is POSIX?
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Exactly. Only the files in linux/ directory can introduce Linux-specific implementations. Always keep POSIX compatibility in mind.
src/tcp.c
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| @@ -1,7 +1,12 @@ | |||
| #if defined __linux__ | |||
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Rewrite as #if defined (__linux__)
src/tcp.c
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| srand(time(NULL)); | ||
| rs->tcp_seqno = rand() % 100; | ||
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| #if defined __linux__ |
jserv
changed the title
Previous generator may not work correctly, so replaced
it with kernel random number source devices