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path: root/apt-pkg/acquire-item.cc
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2015-09-14fallback to well-known URI if by-hash failsDavid Kalnischkies
We uses a small trick to implement the fallback: We make it so, that by-hash is a special compression algorithm and apt already knows how to deal with fallback between compression algorithms. The drawback with implementing this fallback is that a) we are guessing again and more importantly b) by-hash is only tried for the first compression algorithm we want to acquire, not for all as before – but flipping between by-hash and well-known for each compression algorithm seems to be not really worth it as it seems unlikely that there will actually be mirrors who only mirror a subset of compressioned files, but have by-hash enabled. The user-experience is the usual fallback one: You see "Ign" lines in the apt update output. The fallback is implemented as a transition feature, so a (potentially huge) mirror network doesn't need a flagday. It is not meant as a "someday we might" or "we don't, but some of our mirrors might" option – we want to cut down on the 'Ign' lines front so that they become meaningful – if we wanted to spam everyone with them, we could enable by-hash by default for all repositories… sources.list and config options are better suited for this. Closes: 798919
2015-09-14add by-hash sources.list option and document all of by-hashDavid Kalnischkies
This changes the semantics of the option (which is renamed too) to be a yes/no value with the special additional value "force" as this allows by-hash to be disabled even if the repository indicates it would be supported and is more in line with our other yes/no options like pdiff which disable themselves if no support can be detected. The feature wasn't documented so far and hasn't reached a (un)stable release yet, so changing it without trying too hard to keep compatibility seems okay.
2015-09-14avoid using global PendingError to avoid failing too often too soonDavid Kalnischkies
Our error reporting is historically grown into some kind of mess. A while ago I implemented stacking for the global error which is used in this commit now to wrap calls to functions which do not report (all) errors via return, so that only failures in those calls cause a failure to propergate down the chain rather than failing if anything (potentially totally unrelated) has failed at some point in the past. This way we can avoid stopping the entire acquire process just because a single source produced an error for example. It also means that after the acquire process the cache is generated – even if the acquire process had failures – as we still have the old good data around we can and should generate a cache for (again). There are probably more instances of this hiding, but all these looked like the easiest to work with and fix with reasonable (aka net-positive) effects.
2015-08-31ignore for _apt inaccessible TMPDIR in pkgAcqChangelogDavid Kalnischkies
Using libpam-tmpdir caused us to create our download tmp directory in root's private tmp before changing to _apt, which wouldn't have access to it. By extending our GetTempDir method with an optional wrapper changing the effective user, we can test if a given user can access the directory and ignore TMPDIR if not instead of ignoring TMPDIR completely. Closes: 797270
2015-08-28implement PDiff patching for compressed filesDavid Kalnischkies
Some additional files like 'Contents' are very big and should therefore kept compressed on the disk, which apt-file did in the past. It also implemented pdiff patching of these files by un- and recompressing these files on-the-fly, with this commit we can do the same – but we can do this in both pdiff patching styles (client and server merging) and secured by hashes. Hashes are in so far slightly complicated as we can't compare the hashes of the compressed files as we might compress them differently than the server would (different compressor versions, options, …), so we must compare the hashes of the uncompressed content. While this commit has changes in public headers, the classes it changes are marked as hidden, so nobody can use them directly, which means the ABI break is internal only.
2015-08-27sources.list and indextargets option for pdiffsDavid Kalnischkies
Disabling pdiffs can be useful occasionally, like if you have a fast local mirror where the download doesn't matter, but still want to use it for non-local mirrors. Also, some users might prefer it to only use it for very big indextargets like Contents.
2015-08-27use always priv-dropping for changelog download as rootDavid Kalnischkies
First of, the temporary directory we download the changelog to needs to be owned by _apt, but that also means that we don't need to check if we could/should drop privs as the download happens to a dedicated tempdir and only after that it is moved to its final location by a privileged user.
2015-08-17Fix all the wrong removals of includes that iwyu got wrongMichael Vogt
Git-Dch: ignore
2015-08-17Cleanup includes after running iwyuMichael Vogt
2015-08-10drop extra newline in 'Failed to fetch' and 'GPG error' messageDavid Kalnischkies
I never understood why there is an extra newline in those messages, so now is as good time as any to drop them. Lets see if someone complains with a good reason to keep it…
2015-08-10enhance "hit paywall" error message to mention the probable causeDavid Kalnischkies
Reporting errors from Done() is bad for progress reporting and such, so factoring this out is a good idea and we start with moving the supposed- to-be clearsigned file isn't clearsigned out first – improving the error message in the process as we use the same message for a similar case (NODATA) as this is what I have to look at with the venue wifi at DebCamp and the old errormessage doesn't really say anything.
2015-08-10handle site-changing redirects as mirror changesDavid Kalnischkies
Redirectors like httpredir.debian.org orchestra the download from multiple (hopefully close) mirrors while having only a single central sources.list entry by using redirects. This has the effect that the progress report always shows the source it started with, not the mirror it ends up fetching from, which is especially problematic for error reporting as having a report for a "Hashsum mismatch" for the redirector URI is next to useless as nobody knows which URI it was really fetched from (regardless of it coming from a user or via the report script) from this output alone. You would need to enable debug output and hope for the same situation to arise again… We hence reuse the UsedMirror field of the mirror:// method and detect redirects which change the site and declare this new site as the UsedMirrror (and adapt the description). The disadvantage is that there is no obvious mapping anymore (it is relatively easy to guess through with some experience) from progress lines to sources.list lines, so error messages need to take care to use the Target description (rather than current Item description) if they want to refer to the sources.list entry.
2015-08-10skip .diff/Index acquire if Release file was a hitDavid Kalnischkies
QuereURI already skips the aquire of the real file in such a case, but it can't detect pdiffs this way. Those already have a handling if the file wasn't changed in between two Release files, so we just add an other check for a Release file hit here, too. Git-Dch: Ignore
2015-08-10add c++11 override marker to overridden methodsDavid Kalnischkies
C++11 adds the 'override' specifier to mark that a method is overriding a base class method and error out if not. We hide it in the APT_OVERRIDE macro to ensure that we keep compiling in pre-c++11 standards. Reported-By: clang-modernize -add-override -override-macros Git-Dch: Ignore
2015-08-10allow individual targets to be kept compressedDavid Kalnischkies
There is an option to keep all targets (Packages, Sources, …) compressed for a while now, but the all-or-nothing approach is a bit limited for our purposes with additional targets as some of them are very big (Contents) and rarely used in comparison, so keeping them compressed by default can make sense, while others are still unpacked. Most interesting is the copy-change maybe: Copy is used by the acquire system as an uncompressor and it is hence expected that it returns the hashes for the "output", not the input. Now, in the case of keeping a file compressed, the output is never written to disk, but generated in memory and we should still validated it, so for compressed files copy is expected to return the hashes of the uncompressed file. We used to use the config option to enable on-the-fly decompress in the method, but in reality copy is never used in a way where it shouldn't decompress a compressed file to get its hashes, so we can save us the trouble of sending this information to the method and just do it always.
2015-08-10implement Signed-By option for sources.listDavid Kalnischkies
Limits which key(s) can be used to sign a repository. Not immensely useful from a security perspective all by itself, but if the user has additional measures in place to confine a repository (like pinning) an attacker who gets the key for such a repository is limited to its potential and can't use the key to sign its attacks for an other (maybe less limited) repository… (yes, this is as weak as it sounds, but having the capability might come in handy for implementing other stuff later).
2015-08-10add sources.list Check-Valid-Until and Valid-Until-{Max,Min} optionsDavid Kalnischkies
These options could be set via configuration before, but the connection to the actual sources is so strong that they should really be set in the sources.list instead – especially as this can be done a lot more specific rather than e.g. disabling Valid-Until for all sources at once. Valid-Until-* names are chosen instead of the Min/Max-ValidTime as this seems like a better name and their use in the wild is probably low enough that this isn't going to confuse anyone if we have to names for the same thing in different areas. In the longrun, the config options should be removed, but for now documentation hinting at the new options is good enough as these are the kind of options you set once across many systems with different apt versions, so the new way should work everywhere first before we deprecate the old way.
2015-08-10merge indexRecords into metaIndexDavid Kalnischkies
indexRecords was used to parse the Release file – mostly the hashes – while metaIndex deals with downloading the Release file, storing all indexes coming from this release and … parsing the Release file, but this time mostly for the other fields. That wasn't a problem in metaIndex as this was done in the type specific subclass, but indexRecords while allowing to override the parsing method did expect by default a specific format. APT isn't really supporting different types at the moment, but this is a violation of the abstraction we have everywhere else and, which is the actual reason for this merge: Options e.g. coming from the sources.list come to metaIndex naturally, which needs to wrap them up and bring them into indexRecords, so the acquire system is told about it as they don't get to see the metaIndex, but they don't really belong in indexRecords as this is just for storing data loaded from the Release file… the result is a complete mess. I am not saying it is a lot prettier after the merge, but at least adding new options is now slightly easier and there is just one place responsible for parsing the Release file. That can't hurt.
2015-08-10fix memory leaks reported by -fsanitizeDavid Kalnischkies
Various small leaks here and there. Nothing particularily big, but still good to fix. Found by the sanitizers while running our testcases. Reported-By: gcc -fsanitize Git-Dch: Ignore
2015-08-10make all d-pointer * const pointersDavid Kalnischkies
Doing this disables the implicit copy assignment operator (among others) which would cause hovac if used on the classes as it would just copy the pointer, not the data the d-pointer points to. For most of the classes we don't need a copy assignment operator anyway and in many classes it was broken before as many contain a pointer of some sort. Only for our Cacheset Container interfaces we define an explicit copy assignment operator which could later be implemented to copy the data from one d-pointer to the other if we need it. Git-Dch: Ignore
2015-08-10apply various style suggestions by cppcheckDavid Kalnischkies
Some of them modify the ABI, but given that we prepare a big one already, these few hardly count for much. Git-Dch: Ignore
2015-06-16add d-pointer, virtual destructors and de-inline de/constructorsDavid Kalnischkies
To have a chance to keep the ABI for a while we need all three to team up. One of them missing and we might loose, so ensuring that they are available is a very tedious but needed task once in a while. Git-Dch: Ignore
2015-06-15show item ID in Hit, Ign and Err lines as wellDavid Kalnischkies
Again, consistency is the main sellingpoint here, but this way it is now also easier to explain that some files move through different stages and lines are printed for them hence multiple times: That is a bit hard to believe if the number is changing all the time, but now that it keeps consistent.
2015-06-15call URIStart in cdrom and file methodDavid Kalnischkies
All other methods call it, so they should follow along even if the work they do afterwards is hardly breathtaking and usually results in a URIDone pretty soon, but the acquire system tells the individual item about this via a virtual method call, so even through none of our existing items contains any critical code in these, maybe one day they might. Consistency at least once… Which is also why this has a good sideeffect: file: and cdrom: requests appear now in the 'apt-get update' output. Finally - it never made sense to hide them for me. Okay, I guess it made before the new hit behavior, but now that you can actually see the difference in an update it makes sense to see if a file: repository changed or not as well.
2015-06-15deal better with acquiring the same URI multiple timesDavid Kalnischkies
This is an unlikely event for indexes and co, but it can happen quiet easily e.g. for changelogs where you want to get the changelogs for multiple binary package(version)s which happen to all be built from a single source. The interesting part is that the Acquire system actually detected this already and set the item requesting the URI again to StatDone - expect that this is hardly sufficient: an Item must be Complete=true as well to be considered truely done and that is only the tip of the ::Done handling iceberg. So instead of this StatDone hack we allow QItems to be owned by multiple items and notify all owners about everything now, so that for the point of each item they got it downloaded just for them.
2015-06-15provide a public interface for acquiring changelogsDavid Kalnischkies
Provided is a specialized acquire item which given a version can figure out the correct URI to try by itself and if not provides an error message alongside with static methods to get just the URI it would try to download if it should just be displayed or similar such. The URI is constructed as follows: Release files can provide an URI template in the "Changelogs" field, otherwise we lookup a configuration item based on the "Label" or "Origin" of the Release file to get a (hopefully known) default value for now. This template should contain the string CHANGEPATH which is replaced with the information about the version we want the changelog for (e.g. main/a/apt/apt_1.1). This middleway was choosen as this path part was consistent over the three known implementations (+1 defunct), while the rest of the URI varies widely between them. The benefit of this construct is that it is now easy to get changelogs for Debian packages on Ubuntu and vice versa – even at the moment where the Changelogs field is present nowhere. Strictly better than what apt-get had before as it would even fail to get changelogs from security… Now it will notice that security identifies as Origin: Debian and pick this setting (assuming again that no Changelogs field exists). If on the other hand security would ship its changelogs in a different location we could set it via the Label option overruling Origin. Closes: 687147, 739854, 784027, 787190
2015-06-12store Release files data in the CacheDavid Kalnischkies
We used to read the Release file for each Packages file and store the data in the PackageFile struct even through potentially many Packages (and Translation-*) files could use the same data. The point of the exercise isn't the duplicated data through. Having the Release files as first-class citizens in the Cache allows us to properly track their state as well as allows us to use the information also for files which aren't in the cache, but where we know to which Release file they belong (Sources are an example for this). This modifies the pkgCache structs, especially the PackagesFile struct which depending on how libapt users access the data in these structs can mean huge breakage or no visible change. As a single data point: aptitude seems to be fine with this. Even if there is breakage it is trivial to fix in a backportable way while avoiding breakage for everyone would be a huge pain for us. Note that not all PackageFile structs have a corresponding ReleaseFile. In particular the dpkg/status file as well as *.deb files have not. As these have only a Archive property need, the Component property takes over this duty and the ReleaseFile remains zero. This is also the reason why it isn't needed nor particularily recommended to change from PackagesFile to ReleaseFile blindly. Sticking with the earlier is usually the better option.
2015-06-11use IndexTarget to get to IndexFileDavid Kalnischkies
Removes a bunch of duplicated code in the deb-specific parts. Especially the Description part is now handled centrally by IndexTarget instead of being duplicated to the derivations of IndexFile. Git-Dch: Ignore
2015-06-10stop using IndexTarget pointers which are never freedDavid Kalnischkies
Creating and passing around a bunch of pointers of IndexTargets (and of a vector of pointers of IndexTargets) is probably done to avoid the 'costly' copy of container, but we are really not in a timecritical operation here and move semantics will help us even further in the future. On the other hand we never do a proper cleanup of these pointers, which is very dirty, even if structures aren't that big… The changes will effecting many items only effect our own hidden class, so we can do that without fearing breaking interfaces or anything. Git-Dch: Ignore
2015-06-10store all targets data in IndexTarget structDavid Kalnischkies
We still need an API for the targets, so slowly prepare the IndexTargets to let them take this job. Git-Dch: Ignore
2015-06-09remove debianism file-content verificationDavid Kalnischkies
The code requires every index file we download to have a Package field, but that doesn't hold true for all index we might want to download in the future. Some might not even be deb822 formatted files… The check was needed as apt used to accept unverifiable files like Translation-*, but nowadays it requires hashes for these as well. Even for unsigned repositories we interpret the Release file as binding now, which means this check isn't triggerable expect for repositories which do not have a Release file at all – something which is highly discouraged! Git-Dch: Ignore
2015-06-09do not request files if we expect an IMS hitDavid Kalnischkies
If we have a file on disk and the hashes are the same in the new Release file and the old one we have on disk we know that if we ask the server for the file, we will at best get an IMS hit – at worse the server doesn't support this and sends us the (unchanged) file and we have to run all our checks on it again for nothing. So, we can save ourselves (and the servers) some unneeded requests if we figure this out on our own.
2015-06-09cleanup pdiff support detection decisionDavid Kalnischkies
Its a bit unclean to create an item just to let the item decide that it can't do anything and let it fail, so instead we let the item creator decide in all cases if patching should be attempted. Also pulls a small trick to get the hashes for the current file without calculating them by looking at the 'old' Release file if we have it. Git-Dch: Ignore
2015-06-09support hashes for compressed pdiff filesDavid Kalnischkies
At the moment we only have hashes for the uncompressed pdiff files, but via the new '$HASH-Download' field in the .diff/Index hashes can be provided for the .gz compressed pdiff file, which apt will pick up now and use to verify the download. Now, we "just" need a buy in from the creators of repositories…
2015-06-09check patch hashes in rred worker instead of in the handlerDavid Kalnischkies
rred is responsible for unpacking and reading the patch files in one go, but we currently only have hashes for the uncompressed patch files, so the handler read the entire patch file before dispatching it to the worker which would read it again – both with an implicit uncompress. Worse, while the workers operate in parallel the handler is the central orchestration unit, so having it busy with work means the workers do (potentially) nothing. This means rred is working with 'untrusted' data, which is bad. Yet, having the unpack in the handler meant that the untrusted uncompress was done as root which isn't better either. Now, we have it at least contained in a binary which we can harden a bit better. In the long run, we want hashes for the compressed patch files through to be safe.
2015-06-09rework hashsum verification in the acquire systemDavid Kalnischkies
Having every item having its own code to verify the file(s) it handles is an errorprune process and easy to break, especially if items move through various stages (download, uncompress, patching, …). With a giant rework we centralize (most of) the verification to have a better enforcement rate and (hopefully) less chance for bugs, but it breaks the ABI bigtime in exchange – and as we break it anyway, it is broken even harder. It shouldn't effect most frontends as they don't deal with the acquire system at all or implement their own items, but some do and will need to be patched (might be an opportunity to use apt on-board material). The theory is simple: Items implement methods to decide if hashes need to be checked (in this stage) and to return the expected hashes for this item (in this stage). The verification itself is done in worker message passing which has the benefit that a hashsum error is now a proper error for the acquire system rather than a Done() which is later revised to a Failed().
2015-06-07don't try other compressions on hashsum mismatchDavid Kalnischkies
If we e.g. fail on hash verification for Packages.xz its highly unlikely that it will be any better with Packages.gz, so we just waste download bandwidth and time. It also causes us always to fallback to the uncompressed Packages file for which the error will finally be reported, which in turn confuses users as the file usually doesn't exist on the mirrors, so a bug in apt is suspected for even trying it…
2015-05-18treat older Release files than we already have as an IMSHitDavid Kalnischkies
Valid-Until protects us from long-living downgrade attacks, but not all repositories have it and an attacker could still use older but still valid files to downgrade us. While this makes it sounds like a security improvement now, its a bit theoretical at best as an attacker with capabilities to pull this off could just as well always keep us days (but in the valid period) behind and always knows which state we have, as we tell him with the If-Modified-Since header. This is also why this is 'silently' ignored and treated as an IMSHit rather than screamed at the user as this can at best be an annoyance for attackers. An error here would 'regularily' be encountered by users by out-of-sync mirrors serving a single run (e.g. load balancer) or in two consecutive runs on the other hand, so it would just help teaching people ignore it. That said, most of the code churn is caused by enforcing this additional requirement. Crisscross from InRelease to Release.gpg is e.g. very unlikely in practice, but if we would ignore it an attacker could sidestep it this way.
2015-05-13detect Releasefile IMS hits even if the server doesn'tDavid Kalnischkies
Not all servers we are talking to support If-Modified-Since and some are not even sending Last-Modified for us, so in an effort to detect such hits we run a hashsum check on the 'old' compared to the 'new' file, we got the hashes for the 'new' already for "free" from the methods anyway and hence just need to calculated the old ones. This allows us to detect hits even with unsupported servers, which in turn means we benefit from all the new hit behavior also here.
2015-05-12implement VerifyFile as all-hashes checkDavid Kalnischkies
It isn't used much compared to what the methodname suggests, but in the remaining uses it can't hurt to check more than strictly necessary by calculating and verifying with all hashes we can compare with rather than "just" the best known hash.
2015-05-11improve partial/ cleanup in abort and failure casesDavid Kalnischkies
Especially pdiff-enhanced downloads have the tendency to fail for various reasons from which we can recover and even a successful download used to leave the old unpatched index in partial/. By adding a new method responsible for making the transaction of an individual file happen we can at specialisations especially for abort cases to deal with the cleanup. This also helps in keeping the compressed indexes around if another index failed instead of keeping the decompressed files, which we wouldn't pick up in the next call.
2015-04-19hide first pdiff merge failure debug messageDavid Kalnischkies
The sibling of this message are all guarded as debug messages, just this one had it missing an subsequently causes display issues if triggered. Git-Dch: Ignore
2015-04-19a hit on Release files means the indexes will be hits tooDavid Kalnischkies
If we get a IMSHit for the Transaction-Manager (= the InRelease file or as its still supported fallback Release + Release.gpg combo) we can assume that every file we would queue based on this manager, but already have locally is current and hence would get an IMSHit, too. We therefore save us and the server the trouble and skip the queuing in this case. Beside speeding up repetative executions of 'apt-get update' this way we also avoid hitting hashsum errors if the indexes are in fact already updated, but the Release file isn't yet as it is the case on well behaving mirrors as Release files is updated last. The implementation is a bit harder than the theory makes it sound as we still have to keep reverifying the Release files (e.g. to detect now expired once to avoid an attacker being able to silently stale us) and have to handle cases in which the Release file hits, but some indexes aren't present (e.g. user added a new foreign architecture).
2015-04-19refactor calculation of final lists/ name from URIDavid Kalnischkies
Calculating the final name of an item which it will have after everything is done and verified successfully is suprisingly complicated as while they all follow a simple pattern, the URI and where it is stored varies between the items. With some (abibreaking) redesign we can abstract this similar to how it is already down for the partial file location. Git-Dch: Ignore
2015-04-19unsigned Release files can expire, tooDavid Kalnischkies
Checking Valid-Until on an unsigned Release file doesn't give us any security brownie points as an attacker could just change the date and in practice repositories with unsigned Release files will very likely not have a Valid-Until date, but for symetry and the fact that being unsigned is currently just a warning, while expired is a fatal error.
2014-11-08guard const-ification API changesDavid Kalnischkies
Git-Dch: Ignore
2014-11-08replace ignore-deprecated #pragma dance with _PragmaDavid Kalnischkies
For compatibility we use/provide and fill quiet some deprecated methods and fields, which subsequently earns us a warning for using them. These warnings therefore have to be disabled for these codeparts and that is what this change does now in a slightly more elegant way. Git-Dch: Ignore
2014-11-08reenable patchsize limit option for pdiffsDavid Kalnischkies
One word: "doh!" Commit f6d4ab9ad8a2cfe52737ab620dd252cf8ceec43d disabled the check to prevent apt from downloading bigger patches than the index it tries to patch. Happens rarly of course, but still. Detected by scan-build complaining about a dead assignment. To make up for the mistake a test is included as well.
2014-11-06Merge remote-tracking branch 'upstream/debian/experimental' into ↵Michael Vogt
feature/no-more-acquire-guessing Conflicts: apt-pkg/acquire-item.cc
2014-11-04Call "Dequeue()" for items in AbortTransaction() to fix raceMichael Vogt
The pkgAcquire::Run() code works uses a while(ToFetch > 0) loop over the items queued for fetching. This means that we need to Deqeueue the item if we call AbortTransaction() to avoid a hang.