View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0001726 | Issue 8 drafts | System Interfaces | public | 2023-05-10 06:29 | 2024-06-11 09:12 |
| Reporter | Florian Weimer | Assigned To | |||
| Priority | normal | Severity | Editorial | Type | Clarification Requested |
| Status | Closed | Resolution | Accepted As Marked | ||
| Product Version | Draft 3 | ||||
| Name | Florian Weimer | ||||
| Organization | Red Hat | ||||
| User Reference | swbz#178 | ||||
| Section | strlcat | ||||
| Page Number | 2133 | ||||
| Line Number | 69861 | ||||
| Final Accepted Text | 0001726:0006382 | ||||
| Summary | 0001726: strlcat specification is ambiguous regarding return value | ||||
| Description | A glibc developer tried to implement a hand-written assembler version of strlcat based on the POSIX specification and the OpenBSD manual page, and they were surprised when our test suite flagged their implementation as broken. Effectively, we test that strlcat (buf, src, 0) is equivalent to: strlen (src) But the specification can be easily read as saying that it should be strlen (buf) + strlen (src) i.e., that it does not matter whether the original contents of the destination buffer contains null bytes or not. | ||||
| Desired Action | Existing implementations use the buffer size as a bound for the length of the original buffer contents. This is documented fairly explicitly in the Solaris manual page: “The function returns min{dstsize, strlen(dst)} + strlen(src).” <https://docs.oracle.com/cd/E36784_01/html/E36874/strlcat-3c.html> I think the POSIX version should be change so that it is clear that it does not mandate a different behavior. Either it should say explicitly that the return value of strlcat is strnlen(dst, dstsize) + strlen(src) or that strlcat behavior is undefined if there is no null byte among the first dstsize bytes in the buffer at buf. | ||||
| Tags | applied_after_i8d3, issue8 | ||||
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Sorry, the <> markup garbled the link, it should be: https://docs.oracle.com/cd/E36784_01/html/E36874/strlcat-3c.html |
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Change:Upon successful completion, the strlcat() function shall return the initial length of the string pointed to by dst plus the length of the string pointed to by src.to: Upon successful completion, the strlcat() function shall return the initial length of the string (if any) pointed to by dst, as limited by dstsize, plus the length of the string pointed to by src; that is, the value that would be returned by strnlen(dst, dstsize) + strlen(src) before the strlcat() call. |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2023-05-10 06:29 | Florian Weimer | New Issue | |
| 2023-05-10 06:29 | Florian Weimer | Name | => Florian Weimer |
| 2023-05-10 06:29 | Florian Weimer | Organization | => Red Hat |
| 2023-05-10 06:29 | Florian Weimer | User Reference | => swbz#178 |
| 2023-05-10 06:29 | Florian Weimer | Section | => strlcat |
| 2023-05-10 06:29 | Florian Weimer | Page Number | => unknown |
| 2023-05-10 06:29 | Florian Weimer | Line Number | => unknown |
| 2023-05-10 06:30 | Florian Weimer | Note Added: 0006277 | |
| 2023-05-23 14:01 | geoffclare | Project | 1003.1(2013)/Issue7+TC1 => Issue 8 drafts |
| 2023-05-23 14:03 | geoffclare | Page Number | unknown => 2133 |
| 2023-05-23 14:03 | geoffclare | Line Number | unknown => 69861 |
| 2023-05-23 14:03 | geoffclare | Product Version | => Draft 3 |
| 2023-07-10 16:24 | geoffclare | Note Added: 0006382 | |
| 2023-07-10 16:25 | geoffclare | Final Accepted Text | => 0001726:0006382 |
| 2023-07-10 16:25 | geoffclare | Status | New => Resolved |
| 2023-07-10 16:25 | geoffclare | Resolution | Open => Accepted As Marked |
| 2023-07-10 16:25 | geoffclare | Tag Attached: issue8 | |
| 2023-08-08 11:09 | geoffclare | Status | Resolved => Applied |
| 2023-08-08 11:09 | geoffclare | Tag Attached: applied_after_i8d3 | |
| 2024-06-11 09:12 | agadmin | Status | Applied => Closed |
