Dmitrii Stepanov
0fccfe8fcc
The use of network interfaces does not cover cases where it is necessary to use network interfaces to access different subnets. Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>
56 lines
1.3 KiB
Markdown
56 lines
1.3 KiB
Markdown
# Source-based routing in Golang
|
|
|
|
|
|
Consider this routing table:
|
|
```
|
|
10.11.70.0/23 dev data0 proto kernel scope link src 10.11.70.42
|
|
10.11.70.0/23 dev data1 proto kernel scope link src 10.11.71.42
|
|
192.168.123.0/24 dev internal0 proto kernel scope link src 192.168.123.42
|
|
192.168.123.0/24 dev internal1 proto kernel scope link src 192.168.123.142
|
|
```
|
|
|
|
Simple `net.Dial` to either `10.11.70.42` or `10.11.71.42` will match the first subnet and be routed via data0.
|
|
This problems is usually solved by bonds.
|
|
But sometimes you need to invent a bicycle.
|
|
|
|
## Usage
|
|
|
|
```golang
|
|
import (
|
|
"context"
|
|
"net"
|
|
"net/netip"
|
|
|
|
"git.frostfs.info/TrueCloudLab/multinet"
|
|
)
|
|
import
|
|
|
|
d, err := multinet.NewDialer(Config{
|
|
Subnets: []Subnet{
|
|
{
|
|
Prefix: netip.MustParsePrefix("10.11.70.0/23"),
|
|
SourceIPs: []netip.Addr{
|
|
netip.MustParseAddr("10.11.70.42"),
|
|
netip.MustParseAddr("10.11.71.42"),
|
|
},
|
|
},
|
|
{
|
|
Prefix: netip.MustParsePrefix("192.168.123.0/24"),
|
|
SourceIPs: []netip.Addr{
|
|
netip.MustParseAddr("192.168.123.42"),
|
|
netip.MustParseAddr("192.168.123.142"),
|
|
},
|
|
},
|
|
},
|
|
Balancer: multinet.BalancerTypeRoundRobin,
|
|
})
|
|
if err != nil {
|
|
// handle error
|
|
}
|
|
|
|
conn, err := d.DialContext(ctx, "tcp", "10.11.70.42")
|
|
if err != nil {
|
|
// handle error
|
|
}
|
|
// do stuff
|
|
```
|