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go-ping / ping

ICMP Ping library for Go
MIT License
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It hangs in unprivileged mode #146

Closed sem-hub closed 3 years ago

sem-hub commented 3 years ago

ping.go example hangs forever but I see ICMP requests and replies: $ ./ping -c 5 www.yandex.ru PING www.yandex.ru (77.88.55.80): ^C --- www.yandex.ru ping statistics --- 5 packets transmitted, 0 packets received, 0 duplicates, 100% packet loss round-trip min/avg/max/stddev = 0s/0s/0s/0s

tcpdump output 5 requests and replies: 15:10:34.417077 IP 192.168.0.3 > 77.88.55.80: ICMP echo request, id 29, seq 0, length 24 15:10:34.423019 IP 77.88.55.80 > 192.168.0.3: ICMP echo reply, id 29, seq 0, length 24 ....

$ getcap ./ping ./ping = cap_net_raw+ep $ sysctl net.ipv4.ping_group_range net.ipv4.ping_group_range = 0 2147483647 $ lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 20.04.2 LTS Release: 20.04 Codename: focal $ go version go version go1.15.8 linux/amd64

Should it send UDP packets instead of ICMP in unprivileged mode? It works in privileged mode as expected: $ ./ping --privileged www.yandex.ru PING www.yandex.ru (5.255.255.5): 24 bytes from 5.255.255.5: icmp_seq=0 time=8.114374ms ttl=55 24 bytes from 5.255.255.5: icmp_seq=1 time=8.309559ms ttl=55

Any ideas please?

CHTJonas commented 3 years ago

Ugh more platform-dependant behaviour... Thanks for reporting this!

CHTJonas commented 3 years ago

Fixed in commit 5f9dd90 as part of #150's squash-and-merge.