I am writing a Python wrapper around Appium server. Appium accepts command-line parameter for a local port to bind to. Unfortunately, Appium cannot autoselect a free port for itself, so it either binds to explicitly specified port, or fails with EADDRINUSE. Even when telling it to bind to port 0, it will star…
Tag: networking
Be confused with msg_name field in msghdr structure
In user space, I encapsulated a L3 packet using sock_raw (including IP header) and send to kernel space using sock_sendmsg() using msghdr structure I cannot understand clearly the roles of msg_name. I already specified the source IP and dest IP in L3 header. Why do I need msg_name? Answer The msg_name and msg…
Bash parse output in route command
I am writing a bash script to register the remote hosts in a wireless network. I am getting the remote IPs, but I need help to parse the output. Here’s my output: I need to get these IPs and insert into a command like … <remote_ip_1> … How can it be done? I couldn’t find this cas…
is rmem_default size per socket or for entire stack?
Does setting the net.core.rmem_default effect each socket or all sockets opened in the system? What is the maximum value I can configure for the net.core.rmem_default parameter? I understand it depends on RAM. Assume I have much RAM available. Answer net.core.rmem_default is the size of the incoming kernel so…
Receive (recv) full request (e.g. curl HTTP)
How should this be done? I want to receive a (rather long) HTTP request and cannot get this to work. The problem: Without flags, recv does not read the whole message. I guess this is normal behavior. From what I understand using the MSG_WAITALL flag causes it to block until everything is received. However, in…
linux ip routing with multiple uplinks SINGLE interface
trying to setup a Proxmox machine that is running 3 vms. it has 3 public ips but these ips are on a single interface (eth0). the 3 vms are on a bridge (vmbr0) with an address of 172.16.0.1/24 I have enable ip masquerading and forwarding. but I cannot figure out how to make each of the 3 vms (172.16.0.2, 172.1…
Curl returned ststus 6 (DNS name bad address error)
I am unable to resolve host names when one(3g-cell) of my two interfaces is turned on. One interface is WAN(Ethernet), while the other is 3g-Cell. When WAN is turned off, I tried to do manual curl request and I was able to do it using 3g-cell interface, but was unable to do that using hostname. (same happened…
How to connect raspberry pi to internet? [closed]
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. This question does not appear to be about a specific programming problem, a software algorithm, or software tools primarily used by programmers. If you believe the question would be on-topic on another Stack …
iwlib trying to get access point name – u.addr.sa_data contains suspicious characters resulting empty QString
I have following simple method: Now, I would like to extract Access Point MAC address using this method from wrq structure – its u.addr.sa_data member, which (I THINK SO, AM NOT SURE) containts MAC address of Access Point. Follownig debug screenshot shows value of u.addr.sa_data member: Why am I getting…
C socket programming: Set ip header’s id to 0?
I want to send raw IP packets, which works perfectly fine, except for one field in the IP header. I need to set the IP id to 0. I tried it the following way: I then create a RAW_SOCKET with the IP_HDRINCL option set: I then create a buffer, containing my IP header, UDP header and the payload and send