The previous implementation of the parser for /etc/network/interfaces had
quite a few drawbacks:
- it expected the lines to be terminated with "\n", even the last line
- it ignored line wraps with "\\" followed by "\n"
- it expected over-long lines to be shorter than 510 characters
- it ignored line wraps on over-long lines
- it treated spaces and tabs differently
- it did not make sure to really tokenize on word boundaries
- it treated the equivalent stanzas "auto" and "allow-auto" differently
- it ignored the fact that the "allow-*" stanzas can take multiple arguments
that need to be separated to be recognized NetworkManager's processing later
- it allowed "non-block" stanzas to appear before a block
This patch is a rewrite of the parser to fix the issues mentioned:
- it accepts the last line even if it is not terminated by "\n"
- it skips over-long lines, emits a warning and even takes into account
that over-long lines may be wrapped to next lines
- it un-wraps wrapped lines
- it uses spaces and tabs equivalently to tokenize the input
- it treats "allow-auto" as a synonym to "auto"
- it splits multi-argument "auto"/"allow-*" into multiple
single-argument stanzas of the same type
- it warns on data stanzas before the first block stanza
The only thing that doesn't work yet is the system-settings service's
"auto eth" connections for ethernet devices that don't have an existing
connection. Might also have issues with unmanaged devices that can't
provide a MAC address until they are brought up, but we'll see.
