b6d0be2d3b
Replace nm_utils_str_simpletokens_extract_next() by
nm_utils_escaped_tokens_split().
nm_utils_escaped_tokens_split() should become our first choice for
parsing and tokenizing.
Note that both nm_utils_str_simpletokens_extract_next() and
nm_utils_escaped_tokens_split() need to strdup the string once,
and tokenizing takes O(n). So, they are roughtly the same performance
wise. The only difference is, that as we iterate through the tokens,
we might abort early on error with nm_utils_str_simpletokens_extract_next()
and not parse the entire string. But that is a small benefit, since we
anyway always strdup() the string (being O(n) already).
Note that to-string will no longer escape ',' and ';'. This is a change
in behavior, of unreleased API. Also note, that escaping these is no
longer necessary, because nmcli soon will also use nm_utils_escaped_tokens_*().
Another change in behavior is that nm_utils_str_simpletokens_extract_next()
treated invalid escape sequences (backslashes followed by an arbitrary
character), buy stripping the backslash. nm_utils_escaped_tokens_*()
leaves such backslashes as is, and only honors them if they are followed
by a whitespace (the delimiter) or another backslash. The disadvantage
of the new approach is that backslashes are treated differently
depending on the following character. The benefit is, that most
backslashes can now be written verbatim, not requiring them to escape
them with a double-backslash.
Yes, there is a problem with these nested escape schemes:
- the caller may already need to escape backslash in shell.
- then nmcli will use backslash escaping to split the rules at ','.
- then nm_ip_routing_rule_from_string() will honor backslash escaping
for spaces.
- then iifname and oifname use backslash escaping for nm_utils_buf_utf8safe_escape()
to express non-UTF-8 characters (because interface names are not
necessarily UTF-8).
This is only redeamed because escaping is really only necessary for very
unusual cases, if you want to embed a backslash, a space, a comma, or a
non-UTF-8 character. But if you have to, now you will be able to express
that.
The other upside of these layers of escaping is that they become all
indendent from each other:
- shell can accept quoted/escaped arguments and will unescape them.
- nmcli can do the tokenizing for ',' (and escape the content
unconditionally when converting to string).
- nm_ip_routing_rule_from_string() can do its tokenizing without
special consideration of utf8safe escaping.
- NMIPRoutingRule takes iifname/oifname as-is and is not concerned
about nm_utils_buf_utf8safe_escape(). However, before configuring
the rule in kernel, this utf8safe escape will be unescaped to get
the interface name (which is non-UTF8 binary).
****************** 2008-12-11: NetworkManager core daemon has moved to git.freedesktop.org! git clone git://git.freedesktop.org/git/NetworkManager/NetworkManager.git ****************** Networking that Just Works -------------------------- NetworkManager attempts to keep an active network connection available at all times. The point of NetworkManager is to make networking configuration and setup as painless and automatic as possible. NetworkManager is intended to replace default route, replace other routes, set IP addresses, and in general configure networking as NM sees fit (with the possibility of manual override as necessary). In effect, the goal of NetworkManager is to make networking Just Work with a minimum of user hassle, but still allow customization and a high level of manual network control. If you have special needs, we'd like to hear about them, but understand that NetworkManager is not intended for every use-case. NetworkManager will attempt to keep every network device in the system up and active, as long as the device is available for use (has a cable plugged in, the killswitch isn't turned on, etc). Network connections can be set to 'autoconnect', meaning that NetworkManager will make that connection active whenever it and the hardware is available. "Settings services" store lists of user- or administrator-defined "connections", which contain all the settings and parameters required to connect to a specific network. NetworkManager will _never_ activate a connection that is not in this list, or that the user has not directed NetworkManager to connect to. How it works: The NetworkManager daemon runs as a privileged service (since it must access and control hardware), but provides a D-Bus interface on the system bus to allow for fine-grained control of networking. NetworkManager does not store connections or settings, it is only the mechanism by which those connections are selected and activated. To store pre-defined network connections, two separate services, the "system settings service" and the "user settings service" store connection information and provide these to NetworkManager, also via D-Bus. Each settings service can determine how and where it persistently stores the connection information; for example, the GNOME applet stores its configuration in GConf, and the system settings service stores its config in distro-specific formats, or in a distro- agnostic format, depending on user/administrator preference. A variety of other system services are used by NetworkManager to provide network functionality: wpa_supplicant for wireless connections and 802.1x wired connections, pppd for PPP and mobile broadband connections, DHCP clients for dynamic IP addressing, dnsmasq for proxy nameserver and DHCP server functionality for internet connection sharing, and avahi-autoipd for IPv4 link-local addresses. Most communication with these daemons occurs, again, via D-Bus. Why doesn't my network Just Work? Driver problems are the #1 cause of why NetworkManager sometimes fails to connect to wireless networks. Often, the driver simply doesn't behave in a consistent manner, or is just plain buggy. NetworkManager supports _only_ those drivers that are shipped with the upstream Linux kernel, because only those drivers can be easily fixed and debugged. ndiswrapper, vendor binary drivers, or other out-of-tree drivers may or may not work well with NetworkManager, precisely because they have not been vetted and improved by the open-source community, and because problems in these drivers usually cannot be fixed. Sometimes, command-line tools like 'iwconfig' will work, but NetworkManager will fail. This is again often due to buggy drivers, because these drivers simply aren't expecting the dynamic requests that NetworkManager and wpa_supplicant make. Driver bugs should be filed in the bug tracker of the distribution being run, since often distributions customize their kernel and drivers. Sometimes, it really is NetworkManager's fault. If you think that's the case, please file a bug at: https://gitlab.freedesktop.org/NetworkManager/NetworkManager/issues Attaching NetworkManager debug logs from the journal (or wherever your distribution directs syslog's 'daemon' facility output, as /var/log/messages or /var/log/daemon.log) is often very helpful, and (if you can get) a working wpa_supplicant config file helps enormously. See the logging section of file contrib/fedora/rpm/NetworkManager.conf for how to enable debug logging in NetworkManager.