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Bug #3419

af_packet cluster_id is not used when trying to set fanout support.

Added by Srinath M. over 1 year ago. Updated 10 months ago.

Status:
Assigned
Priority:
Normal
Assignee:
Target version:
Affected Versions:
Effort:
low
Difficulty:
low
Label:

Description

I was frequently getting the following error message

(source-af-packet.c:2013) <Error> (AFPIsFanoutSupported) -- [ERRCODE: SC_ERR_INVALID_VALUE(130)] - fanout not supported by kernel: Kernel too old or cluster-id 99 already in use.

After checking the kernel and cluster-id I realized that the id set in the config file is never used in the function below where the id is hard-coded to "1" and the variable cluster_id is used only in the error message:

suricata/src/source-af-packet.c

int AFPIsFanoutSupported(int cluster_id)
{
#ifdef HAVE_PACKET_FANOUT
    int fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
    if (fd < 0)
        return 0;

    uint16_t mode = PACKET_FANOUT_HASH | PACKET_FANOUT_FLAG_DEFRAG;
    uint16_t id = 1;
    uint32_t option = (mode << 16) | (id & 0xffff);
    int r = setsockopt(fd, SOL_PACKET, PACKET_FANOUT,(void *)&option, sizeof(option));
    close(fd);

    if (r < 0) {
        SCLogError(SC_ERR_INVALID_VALUE, "fanout not supported by kernel: " 
                "Kernel too old or cluster-id %d already in use.", cluster_id);
        return 0;
    }
    return 1;
#else
    return 0;
#endif
}

I believe that the line:

    uint32_t option = (mode << 16) | (id & 0xffff);

should be changed to:

    uint32_t option = (mode << 16) | (cluster_id & 0xffff);

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