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| author | Dimitri Staessens <dimitri@ouroboros.rocks> | 2019-03-20 18:33:47 +0100 |
|---|---|---|
| committer | Sander Vrijders <sander@ouroboros.rocks> | 2019-03-21 09:42:34 +0100 |
| commit | 086cd5dae628556ffaa2c2efe559a5bd2fba8d0e (patch) | |
| tree | 283abbcacdacd89ace7eae9d66ec9427e69f3666 /src/ipcpd/eth | |
| parent | bb724cad016fba5775e751c817df0a07136d223f (diff) | |
| download | ouroboros-086cd5dae628556ffaa2c2efe559a5bd2fba8d0e.tar.gz ouroboros-086cd5dae628556ffaa2c2efe559a5bd2fba8d0e.zip | |
ipcpd: Restrict MTU for Ethernet over loopback
This restricts the MTU for the Ethernet IPCP over loopback adapters
(devices named "lo*") to avoid it allocating 65K buffers per packet
and quickly filling the default RDRBUFF space. The restriction is set
using the build option IPCP_ETH_LO_MTU, with a default value of 1500
bytes.
Signed-off-by: Dimitri Staessens <dimitri@ouroboros.rocks>
Signed-off-by: Sander Vrijders <sander@ouroboros.rocks>
Diffstat (limited to 'src/ipcpd/eth')
| -rw-r--r-- | src/ipcpd/eth/CMakeLists.txt | 2 | ||||
| -rw-r--r-- | src/ipcpd/eth/eth.c | 5 |
2 files changed, 7 insertions, 0 deletions
diff --git a/src/ipcpd/eth/CMakeLists.txt b/src/ipcpd/eth/CMakeLists.txt index abffbb2d..89575b6b 100644 --- a/src/ipcpd/eth/CMakeLists.txt +++ b/src/ipcpd/eth/CMakeLists.txt @@ -84,6 +84,8 @@ if (HAVE_ETH) "Number of writer threads in Ethernet IPCP") set(IPCP_ETH_QDISC_BYPASS false CACHE BOOL "Bypass the Qdisc in the kernel when using raw sockets") + set(IPCP_ETH_LO_MTU 1500 CACHE STRING + "Restrict Ethernet MTU over loopback interfaces") set(ETH_LLC_SOURCES # Add source files here diff --git a/src/ipcpd/eth/eth.c b/src/ipcpd/eth/eth.c index 04130d6f..1a332272 100644 --- a/src/ipcpd/eth/eth.c +++ b/src/ipcpd/eth/eth.c @@ -1316,6 +1316,11 @@ static int eth_ipcp_bootstrap(const struct ipcp_config * conf) log_dbg("Device MTU is %d.", ifr.ifr_mtu); eth_data.mtu = MIN((int) ETH_MTU_MAX, ifr.ifr_mtu); + if (memcmp(conf->dev, "lo", 2) == 0 && eth_data.mtu > IPCP_ETH_LO_MTU) { + log_dbg("Using loopback interface. MTU restricted to %d.", + IPCP_ETH_LO_MTU); + eth_data.mtu = IPCP_ETH_LO_MTU; + } #ifndef SHM_RDRB_MULTI_BLOCK maxsz = SHM_RDRB_BLOCK_SIZE - 5 * sizeof(size_t) - |