cda33ae4fc
dns_recv_response() checked for room using sizeof(struct dns_answer_s), but that structure is the 10-byte header plus a union holding the largest address it can carry. With IPv6 built the union is 16 bytes, so the check demanded 26 bytes where 10 were needed, and any answer sitting at the end of a response was rejected as truncated. An A record answer supplies 14 bytes, so whether a lookup worked depended on how much padding the server happened to send after it: $ dig +noedns @10.1.1.2 github.com A # ANSWER 1, AUTHORITY 0, ADDITIONAL 0 -> answer is last in the packet, 14 bytes remain, rejected $ dig +noedns @10.11.5.254 github.com A # ANSWER 1, AUTHORITY 13, ADDITIONAL 7 -> 26+ bytes remain, accepted On the board, before and after, against the first of those servers: nsh> nslookup apache.org [CPU1] dns_recv_response: DNS answer header truncated Host: apache.org Addr: 2a04:4e42::644 <- A record lost nsh> nslookup apache.org Host: apache.org Addr: 2a04:4e42::644 Host: apache.org Addr: 151.101.2.132 <- both returned The address that follows the header is already bounds checked separately, where its real length is known, so only the header check was wrong. The size is now a named constant next to the structure, since the rest of this function already used the literal 10 for the same quantity. Only IPv4-only builds escaped it, where sizeof happens to equal 14 and an A record fits exactly. Assisted-by: Claude:claude-opus-5 Signed-off-by: Justin Hammond <justin@dynam.ac> |
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| .github | ||
| arch | ||
| audio | ||
| binfmt | ||
| boards | ||
| cmake | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| dummy | ||
| fs | ||
| graphics | ||
| include | ||
| libs | ||
| mm | ||
| net | ||
| openamp | ||
| pass1 | ||
| sched | ||
| syscall | ||
| tools | ||
| video | ||
| wireless | ||
| .asf.yaml | ||
| .codespell-ignore-lines | ||
| .codespellrc | ||
| .editorconfig | ||
| .gitignore | ||
| .gitmessage | ||
| .pre-commit-config.yaml | ||
| .yamllint | ||
| AUTHORS | ||
| CMakeLists.txt | ||
| CONTRIBUTING.md | ||
| INVIOLABLES.md | ||
| Kconfig | ||
| LICENSE | ||
| Makefile | ||
| NOTICE | ||
| README.md | ||
| ReleaseNotes | ||
Apache NuttX is a real-time operating system (RTOS) with an emphasis on standards compliance and small footprint. Scalable from 8-bit to 64-bit microcontroller environments, the primary governing standards in NuttX are POSIX and ANSI standards. Additional standard APIs from Unix and other common RTOSs (such as VxWorks) are adopted for functionality not available under these standards, or for functionality that is not appropriate for deeply-embedded environments (such as fork()).
For brevity, many parts of the documentation will refer to Apache NuttX as simply NuttX.
Getting Started
First time on NuttX? Read the Getting Started guide! If you don't have a board available, NuttX has its own simulator that you can run on terminal.
Documentation
You can find the current NuttX documentation on the Documentation Page.
Alternatively, you can build the documentation yourself by following the Documentation Build Instructions.
The old NuttX documentation is still available in the Apache wiki.
Supported Boards
NuttX supports a wide variety of platforms. See the full list on the Supported Platforms page.
Contributing
If you wish to contribute to the NuttX project, read the Contributing guidelines for information on Git usage, coding standard, workflow and the NuttX principles.
License
The code in this repository is under either the Apache 2 license, or a license compatible with the Apache 2 license. See the License Page for more information.