Bug 17552
| Summary: | Documentation error in divert(4) | ||
|---|---|---|---|
| Product: | Documentation | Reporter: | sam <sam> |
| Component: | Books & Articles | Assignee: | freebsd-doc (Nobody) <doc> |
| Status: | Closed FIXED | ||
| Severity: | Affects Only Me | ||
| Priority: | Normal | ||
| Version: | Latest | ||
| Hardware: | Any | ||
| OS: | Any | ||
On Wed, Mar 22, 2000 at 06:13:51PM +0100, sam@enst.fr wrote: > >Fix: > > Two possible immediate fixes: > > (1) Doc fix: change divert(4) manpage > > (2) Code fix: when entering div_bind, change the nam->sin_addr field > if nam->sin_family is AF_INET so that it contains INADDR_ANY. It may > break things that would depend on the fact that a diverted socket > can be bound to a particular interface though (natd does use > INADDR_ANY explicitely). According to Brian and Paul (who are sat next to me on the train back from a UK Newcastle meet) this really needs a code change rather than a doc change. So I'm following up to this in order to remind me to reassign this PR to the appropriate people when I get IP connectivity back. . . N -- Internet connection, $19.95 a month. Computer, $799.95. Modem, $149.95. Telephone line, $24.95 a month. Software, free. USENET transmission, hundreds if not thousands of dollars. Thinking before posting, priceless. Somethings in life you can't buy. For everything else, there's MasterCard. -- Graham Reed, in the Scary Devil Monastery State Changed From-To: open->closed The problem was a code error which has now been fixed. |
When developing an toy application using divert(4), I was surprised to see that it was working only if the PF_INET/SOCK_RAW/IPPROTO_DIVERT socket, at bind() time, has a *valid* interface address (such as INADDR_ANY). divert(4) manpage says: The IP ad- dress in the bind is ignored; only the port number is significant. A di- vert socket bound to a divert port will receive all packets diverted to that port by some (here unspecified) kernel mechanism(s). This is false, as the bind() operation for a divert socket will call in_pcbbind() which makes use of the interface address. Fix: Two possible immediate fixes: (1) Doc fix: change divert(4) manpage (2) Code fix: when entering div_bind, change the nam->sin_addr field if nam->sin_family is AF_INET so that it contains INADDR_ANY. It may break things that would depend on the fact that a diverted socket can be bound to a particular interface though (natd does use INADDR_ANY explicitely). How-To-Repeat: Build a PF_INET/SOCK_RAW/IPPROTO_DIVERT socket, bind it with a sockaddr_in structure which has an invalid sin_addr field. Diverted packets will not be available on the socket and will be silently dropped by the kernel as if no diverted socket was listening.