JDK-8319382: com/sun/jdi/JdwpAllowTest.java shows failures on AIX if prefixLen of mask is larger than 32 in IPv6 case

[MBaesken]

In parseAllowedMask (file socketTransport.c) , prefixLen of mask is compared with a maxValue (32 for IPv4, 128 otherwise). This fails on AIX if it is larger than 32, because getaddrinfo seems to often (always ?) detect IPv4 family, even for IPv6 addresses, so we take the wrong maxValue.
Probably we have to adjust the allowed maxValue on AIX, or adjust the IPv6 check.

Example:
images/jdk/bin/java -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=*:0,allow=0:0:0:0:0:0:10:0/106
Error in allow option: '106'
ERROR: transport error 103: invalid netmask in allow option
ERROR: JDWP Transport dt_socket failed to initialize, TRANSPORT_INIT(510)

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Issue

• JDK-8319382: com/sun/jdi/JdwpAllowTest.java shows failures on AIX if prefixLen of mask is larger than 32 in IPv6 case (Bug - P4)

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[plummercj]

IIUC, this code would work for any port, but is only required for AIX. And since it is a hack to work around an AIX issue, you didn't want to subject all ports to it. The downside of this change is that it will cause the option parsing code to not properly produce an error if an IPv4 mask prefix between 32 and 128 is given.

[MBaesken]

The downside of this change is that it will cause the option parsing code to not properly produce an error if an IPv4 mask prefix between 32 and 128 is given.

Yes this is true; maybe we should not unconditionally increase the maxValue on AIX .

[alexmenkov]

The fix looks wrong.
The problem is not with parsing of the prefix len, but with parsing of the address itself (parseAllowedAddr function).
Note that parseAllowedAddr converts returned IPv4 addresses to mapped IPv6 and in the example provided it won't be expected ::10:0, so the "allow" logic will be broken.
I think the issue need some research on the affected systems:

• if getaddrinfo returns AF_INET, then what is returned in ai_addr field? it must be valid IPv4 address (which can be used for connect());
• does getaddrinfo return a single address? (parseAllowedAddr assumes so, but maybe that's wrong in the case)

[MBaesken]

does getaddrinfo return a single address? (parseAllowedAddr assumes so, but maybe that's wrong in the case)

From what I see on AIX, only one entry is returned in the results struct of the getaddrinfo call.

[MBaesken]

A colleague contacted IBM about the different behavior of getaddrinfo on AIX (compared to Linux/macOS); maybe we have to adjust the result of the getaddrinfo call on AIX.

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[MBaesken]

A colleague contacted IBM about the different behavior of getaddrinfo on AIX (compared to Linux/macOS); maybe we have to adjust the result of the getaddrinfo call on AIX.

Haven't heard from them so far, hopefully we get an update soon about the behavior of getaddrinfo on AIX .

[alexmenkov]

@MBaesken Just a thought: parseAllowedAddr() needs to parse only numeric addresses. getaddrinfo was used to handle both IPv4 and IPv6 by a single call, but maybe it would be better to reimplement parseAllowedAddr to do 2 inet_pton calls (for AF_INET and AF_INET6)

[MBaesken]

@MBaesken Just a thought: parseAllowedAddr() needs to parse only numeric addresses. getaddrinfo was used to handle both IPv4 and IPv6 by a single call, but maybe it would be better to reimplement parseAllowedAddr to do 2 inet_pton calls (for AF_INET and AF_INET6)

Hi Alex, this seems to work (for AIX, and also for the other OpenJDK platforms) .