Skip to content

Forms a proper multicast MAC address for multicast IP. #413

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wladwm wants to merge 2 commits into
base: main
Choose a base branch
from
Open

Forms a proper multicast MAC address for multicast IP. #413

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
6a9ea88
Forms a proper multicast MAC address for multicast IP.
Apr 21, 2021
ce778f7
Merge branch 'main' into master
wladwm Nov 8, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 7 additions & 0 deletions src/tcpip.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -379,6 +379,13 @@ void EtherCard::udpPrepare (uint16_t sport, const uint8_t *dip, uint16_t dport)
} else { // checked if dip is dns ip and separately if dip is hisip and then use correct mac.
setMACandIPs(gwmacaddr, dip);
}
//form a valid multicast mac
if ((dip[0] & 0xF0) == 0xE0){
uint8_t cMac[6];cMac[0]=1;cMac[1]=0;cMac[2]=0x5e;
memcpy(&cMac[3],dip+1,3);
cMac[3]&=0x7f;
EtherCard::copyMac(gPB + ETH_DST_MAC, cMac);
} else
// see http://tldp.org/HOWTO/Multicast-HOWTO-2.html
// multicast or broadcast address, https://github.com/njh/EtherCard/issues/59
if ((dip[0] & 0xF0) == 0xE0 || *((unsigned long*) dip) == 0xFFFFFFFF || !memcmp(broadcastip,dip,IP_LEN))

@njh njh Apr 21, 2021

Copy link
Copy Markdown
Owner

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Isn't this a duplicate if statement condition?

Expand Down