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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-13 09:59:37 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-13 09:59:37 +0000 |
commit | 76e2632459410dec81337edb6a9fee33c9a660f3 (patch) | |
tree | a73345df208eede4a4daad340515c9328f34625c /methods/aptmethod.h | |
parent | Initial commit. (diff) | |
download | apt-76e2632459410dec81337edb6a9fee33c9a660f3.tar.xz apt-76e2632459410dec81337edb6a9fee33c9a660f3.zip |
Adding upstream version 2.7.12.upstream/2.7.12
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'methods/aptmethod.h')
-rw-r--r-- | methods/aptmethod.h | 595 |
1 files changed, 595 insertions, 0 deletions
diff --git a/methods/aptmethod.h b/methods/aptmethod.h new file mode 100644 index 0000000..26b8c0b --- /dev/null +++ b/methods/aptmethod.h @@ -0,0 +1,595 @@ +#ifndef APT_APTMETHOD_H +#define APT_APTMETHOD_H + +#include "config.h" + +#include <apt-pkg/acquire-method.h> +#include <apt-pkg/configuration.h> +#include <apt-pkg/error.h> +#include <apt-pkg/fileutl.h> +#include <apt-pkg/netrc.h> +#include <apt-pkg/strutl.h> + +#include <algorithm> +#include <locale> +#include <memory> +#include <string> +#include <vector> + +#include <cstdlib> +#include <sys/stat.h> +#include <sys/time.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <unistd.h> + +#include <apti18n.h> + +#ifdef HAVE_SECCOMP +#include <csignal> + +#include <seccomp.h> +#endif + +enum class ResultState +{ + TRANSIENT_ERROR, + FATAL_ERROR, + SUCCESSFUL +}; + +static bool hasDoubleColon(std::string const &n) +{ + return n.find("::") != std::string::npos; +} + +class aptConfigWrapperForMethods +{ +protected: + std::vector<std::string> methodNames; +public: + void setPostfixForMethodNames(char const * const postfix) APT_NONNULL(2) + { + methodNames.erase(std::remove_if(methodNames.begin(), methodNames.end(), hasDoubleColon), methodNames.end()); + decltype(methodNames) toAdd; + for (auto && name: methodNames) + toAdd.emplace_back(name + "::" + postfix); + std::move(toAdd.begin(), toAdd.end(), std::back_inserter(methodNames)); + } + + bool DebugEnabled() const + { + if (methodNames.empty()) + return false; + auto const sni = std::find_if_not(methodNames.crbegin(), methodNames.crend(), hasDoubleColon); + if (unlikely(sni == methodNames.crend())) + return false; + auto const ln = methodNames[methodNames.size() - 1]; + // worst case: all three are the same + std::string confln, confsn, confpn; + strprintf(confln, "Debug::Acquire::%s", ln.c_str()); + strprintf(confsn, "Debug::Acquire::%s", sni->c_str()); + auto const pni = sni->substr(0, sni->find('+')); + strprintf(confpn, "Debug::Acquire::%s", pni.c_str()); + return _config->FindB(confln,_config->FindB(confsn, _config->FindB(confpn, false))); + } + std::string ConfigFind(char const * const postfix, std::string const &defValue) const APT_NONNULL(2) + { + for (auto name = methodNames.rbegin(); name != methodNames.rend(); ++name) + { + std::string conf; + strprintf(conf, "Acquire::%s::%s", name->c_str(), postfix); + auto value = _config->Find(conf); + if (not value.empty()) + return value; + } + return defValue; + } + std::string ConfigFind(std::string const &postfix, std::string const &defValue) const + { + return ConfigFind(postfix.c_str(), defValue); + } + bool ConfigFindB(char const * const postfix, bool const defValue) const APT_NONNULL(2) + { + return StringToBool(ConfigFind(postfix, defValue ? "yes" : "no"), defValue); + } + int ConfigFindI(char const * const postfix, int const defValue) const APT_NONNULL(2) + { + char *End; + std::string const value = ConfigFind(postfix, ""); + auto const Res = strtol(value.c_str(), &End, 0); + if (value.c_str() == End) + return defValue; + return Res; + } + + explicit aptConfigWrapperForMethods(std::string const &name) : methodNames{{name}} {} + explicit aptConfigWrapperForMethods(std::vector<std::string> &&names) : methodNames{std::move(names)} {} +}; + +class aptMethod : public pkgAcqMethod, public aptConfigWrapperForMethods +{ +protected: + std::string const Binary; + unsigned long SeccompFlags; + enum Seccomp + { + BASE = (1 << 1), + NETWORK = (1 << 2), + DIRECTORY = (1 << 3), + }; + + public: + virtual bool Configuration(std::string Message) APT_OVERRIDE + { + if (pkgAcqMethod::Configuration(Message) == false) + return false; + + std::string const conf = std::string("Binary::") + Binary; + _config->MoveSubTree(conf.c_str(), NULL); + + DropPrivsOrDie(); + if (LoadSeccomp() == false) + return false; + + return true; + } + + bool RunningInQemu(void) + { + int status; + pid_t pid; + + pid = fork(); + if (pid == 0) + { + close(0); + close(1); + close(2); + setenv("QEMU_VERSION", "meow", 1); + char path[] = LIBEXEC_DIR "/apt-helper"; + char *const argv[] = {path, NULL}; + execv(argv[0], argv); + _exit(255); + } + + // apt-helper is supposed to exit with an error. If it exited with 0, + // qemu-user had problems with QEMU_VERSION and returned 0 => running in + // qemu-user. + + if (waitpid(pid, &status, 0) == pid && WIFEXITED(status) && WEXITSTATUS(status) == 0) + return true; + + return false; + } + + bool LoadSeccomp() + { +#ifdef HAVE_SECCOMP + int rc; + scmp_filter_ctx ctx = NULL; + + if (SeccompFlags == 0) + return true; + + if (_config->FindB("APT::Sandbox::Seccomp", false) == false) + return true; + + if (RunningInQemu() == true) + { + Warning("Running in qemu-user, not using seccomp"); + return true; + } + + ctx = seccomp_init(SCMP_ACT_TRAP); + if (ctx == NULL) + return _error->FatalE("HttpMethod::Configuration", "Cannot init seccomp"); + +#define ALLOW(what) \ + if ((rc = seccomp_rule_add(ctx, SCMP_ACT_ALLOW, SCMP_SYS(what), 0))) \ + return _error->FatalE("HttpMethod::Configuration", "Cannot allow %s: %s", #what, strerror(-rc)); + + for (auto &custom : _config->FindVector("APT::Sandbox::Seccomp::Trap")) + { + if ((rc = seccomp_rule_add(ctx, SCMP_ACT_TRAP, seccomp_syscall_resolve_name(custom.c_str()), 0))) + return _error->FatalE("HttpMethod::Configuration", "Cannot trap %s: %s", custom.c_str(), strerror(-rc)); + } + + ALLOW(access); + ALLOW(arch_prctl); + ALLOW(brk); + ALLOW(chmod); + ALLOW(chown); + ALLOW(chown32); + ALLOW(clock_getres); + ALLOW(clock_getres_time64); + ALLOW(clock_gettime); + ALLOW(clock_gettime64); + ALLOW(clock_nanosleep); + ALLOW(clock_nanosleep_time64); + ALLOW(close); + ALLOW(creat); + ALLOW(dup); + ALLOW(dup2); + ALLOW(dup3); + ALLOW(exit); + ALLOW(exit_group); + ALLOW(faccessat); + ALLOW(fchmod); + ALLOW(fchmodat); + ALLOW(fchown); + ALLOW(fchown32); + ALLOW(fchownat); + ALLOW(fcntl); + ALLOW(fcntl64); + ALLOW(fdatasync); + ALLOW(flock); + ALLOW(fstat); + ALLOW(fstat64); + ALLOW(fstatat64); + ALLOW(fstatfs); + ALLOW(fstatfs64); + ALLOW(fsync); + ALLOW(ftime); + ALLOW(ftruncate); + ALLOW(ftruncate64); + ALLOW(futex); + ALLOW(futex_time64); + ALLOW(futimesat); + ALLOW(getegid); + ALLOW(getegid32); + ALLOW(geteuid); + ALLOW(geteuid32); + ALLOW(getgid); + ALLOW(getgid32); + ALLOW(getgroups); + ALLOW(getgroups32); + ALLOW(getpeername); + ALLOW(getpgid); + ALLOW(getpgrp); + ALLOW(getpid); + ALLOW(getppid); + ALLOW(getrandom); + ALLOW(getresgid); + ALLOW(getresgid32); + ALLOW(getresuid); + ALLOW(getresuid32); + ALLOW(getrlimit); + ALLOW(get_robust_list); + ALLOW(getrusage); + ALLOW(gettid); + ALLOW(gettimeofday); + ALLOW(getuid); + ALLOW(getuid32); + ALLOW(ioctl); + ALLOW(lchown); + ALLOW(lchown32); + ALLOW(_llseek); + ALLOW(lseek); + ALLOW(lstat); + ALLOW(lstat64); + ALLOW(madvise); + ALLOW(mmap); + ALLOW(mmap2); + ALLOW(mprotect); + ALLOW(mremap); + ALLOW(msync); + ALLOW(munmap); + ALLOW(nanosleep); + ALLOW(newfstatat); + ALLOW(_newselect); + ALLOW(oldfstat); + ALLOW(oldlstat); + ALLOW(oldolduname); + ALLOW(oldstat); + ALLOW(olduname); + ALLOW(open); + ALLOW(openat); + ALLOW(pipe); + ALLOW(pipe2); + ALLOW(poll); + ALLOW(ppoll); + ALLOW(ppoll_time64); + ALLOW(prctl); + ALLOW(prlimit64); + ALLOW(pselect6); + ALLOW(pselect6_time64); + ALLOW(read); + ALLOW(readv); + ALLOW(rename); + ALLOW(renameat); + ALLOW(renameat2); + ALLOW(restart_syscall); + ALLOW(rt_sigaction); + ALLOW(rt_sigpending); + ALLOW(rt_sigprocmask); + ALLOW(rt_sigqueueinfo); + ALLOW(rt_sigreturn); + ALLOW(rt_sigsuspend); + ALLOW(rt_sigtimedwait); + ALLOW(sched_yield); + ALLOW(select); + ALLOW(set_robust_list); + ALLOW(sigaction); + ALLOW(sigpending); + ALLOW(sigprocmask); + ALLOW(sigreturn); + ALLOW(sigsuspend); + ALLOW(stat); + ALLOW(stat64); + ALLOW(statfs); + ALLOW(statfs64); +#ifdef __NR_statx + ALLOW(statx); +#endif + ALLOW(sync); + ALLOW(syscall); + ALLOW(sysinfo); + ALLOW(time); + ALLOW(truncate); + ALLOW(truncate64); + ALLOW(ugetrlimit); + ALLOW(umask); + ALLOW(uname); + ALLOW(unlink); + ALLOW(unlinkat); + ALLOW(utime); + ALLOW(utimensat); + ALLOW(utimensat_time64); + ALLOW(utimes); + ALLOW(write); + ALLOW(writev); + + if ((SeccompFlags & Seccomp::NETWORK) != 0) + { + ALLOW(bind); + ALLOW(connect); + ALLOW(getsockname); + ALLOW(getsockopt); + ALLOW(recv); + ALLOW(recvfrom); + ALLOW(recvmmsg); + ALLOW(recvmmsg_time64); + ALLOW(recvmsg); + ALLOW(send); + ALLOW(sendmmsg); + ALLOW(sendmsg); + ALLOW(sendto); + ALLOW(setsockopt); + ALLOW(shutdown); + ALLOW(socket); + ALLOW(socketcall); + } + + if ((SeccompFlags & Seccomp::DIRECTORY) != 0) + { + ALLOW(readdir); + ALLOW(getdents); + ALLOW(getdents64); + } + + if (getenv("FAKED_MODE")) + { + ALLOW(semop); + ALLOW(semget); + ALLOW(msgsnd); + ALLOW(msgrcv); + ALLOW(msgget); + ALLOW(msgctl); + ALLOW(ipc); + } + + for (auto &custom : _config->FindVector("APT::Sandbox::Seccomp::Allow")) + { + if ((rc = seccomp_rule_add(ctx, SCMP_ACT_ALLOW, seccomp_syscall_resolve_name(custom.c_str()), 0))) + return _error->FatalE("aptMethod::Configuration", "Cannot allow %s: %s", custom.c_str(), strerror(-rc)); + } + +#undef ALLOW + + rc = seccomp_load(ctx); + if (rc == -EINVAL) + { + std::string msg; + strprintf(msg, "aptMethod::Configuration: could not load seccomp policy: %s", strerror(-rc)); + Warning(std::move(msg)); + } + else if (rc != 0) + return _error->FatalE("aptMethod::Configuration", "could not load seccomp policy: %s", strerror(-rc)); + + if (_config->FindB("APT::Sandbox::Seccomp::Print", true)) + { + struct sigaction action; + memset(&action, 0, sizeof(action)); + sigemptyset(&action.sa_mask); + action.sa_sigaction = [](int, siginfo_t *info, void *) { + // Formats a number into a 10 digit ASCII string + char buffer[10]; + int number = info->si_syscall; + + for (int i = sizeof(buffer) - 1; i >= 0; i--) + { + buffer[i] = (number % 10) + '0'; + number /= 10; + } + + constexpr const char *str1 = "\n **** Seccomp prevented execution of syscall "; + constexpr const char *str2 = " on architecture "; + constexpr const char *str3 = " ****\n"; +#ifdef __GNUC__ +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wunused-result" +#endif + write(2, str1, strlen(str1)); + write(2, buffer, sizeof(buffer)); + write(2, str2, strlen(str2)); + write(2, COMMON_ARCH, strlen(COMMON_ARCH)); + write(2, str3, strlen(str3)); +#ifdef __GNUC__ +#pragma GCC diagnostic pop +#endif + _exit(31); + }; + action.sa_flags = SA_SIGINFO; + + sigaction(SIGSYS, &action, nullptr); + } +#endif + return true; + } + + bool CalculateHashes(FetchItem const * const Itm, FetchResult &Res) const APT_NONNULL(2) + { + Hashes Hash(Itm->ExpectedHashes); + FileFd Fd; + if (Fd.Open(Res.Filename, FileFd::ReadOnly) == false || Hash.AddFD(Fd) == false) + return false; + Res.TakeHashes(Hash); + return true; + } + + void Warning(std::string &&msg) + { + std::unordered_map<std::string, std::string> fields; + if (Queue != 0) + fields.emplace("URI", Queue->Uri); + else + fields.emplace("URI", "<UNKNOWN>"); + if (not UsedMirror.empty()) + fields.emplace("UsedMirror", UsedMirror); + fields.emplace("Message", std::move(msg)); + SendMessage("104 Warning", std::move(fields)); + } + + bool TransferModificationTimes(char const * const From, char const * const To, time_t &LastModified) APT_NONNULL(2, 3) + { + if (strcmp(To, "/dev/null") == 0) + return true; + + struct stat Buf2; + if (lstat(To, &Buf2) != 0 || S_ISLNK(Buf2.st_mode)) + return true; + + struct stat Buf; + if (stat(From, &Buf) != 0) + return _error->Errno("stat",_("Failed to stat")); + + // we don't use utimensat here for compatibility reasons: #738567 + struct timeval times[2]; + times[0].tv_sec = Buf.st_atime; + LastModified = times[1].tv_sec = Buf.st_mtime; + times[0].tv_usec = times[1].tv_usec = 0; + if (utimes(To, times) != 0) + return _error->Errno("utimes",_("Failed to set modification time")); + return true; + } + + // This is a copy of #pkgAcqMethod::Dequeue which is private & hidden + void Dequeue() + { + FetchItem const *const Tmp = Queue; + Queue = Queue->Next; + if (Tmp == QueueBack) + QueueBack = Queue; + delete Tmp; + } + static std::string URIEncode(std::string const &part) + { + // The "+" is encoded as a workaround for an S3 bug (LP#1003633 and LP#1086997) + return QuoteString(part, _config->Find("Acquire::URIEncode", "+~ ").c_str()); + } + + static std::string DecodeSendURI(std::string const &part) + { + if (_config->FindB("Acquire::Send-URI-Encoded", false)) + return DeQuoteString(part); + return part; + } + + aptMethod(std::string &&Binary, char const *const Ver, unsigned long const Flags) APT_NONNULL(3) + : pkgAcqMethod(Ver, Flags), aptConfigWrapperForMethods(Binary), Binary(std::move(Binary)), SeccompFlags(0) + { + try { + std::locale::global(std::locale("")); + } catch (...) { + setlocale(LC_ALL, ""); + } + } +}; +class aptAuthConfMethod : public aptMethod +{ + std::vector<std::unique_ptr<FileFd>> authconfs; + + public: + virtual bool Configuration(std::string Message) APT_OVERRIDE + { + if (pkgAcqMethod::Configuration(Message) == false) + return false; + + std::string const conf = std::string("Binary::") + Binary; + _config->MoveSubTree(conf.c_str(), NULL); + + // ignore errors with opening the auth file as it doesn't need to exist + _error->PushToStack(); + auto const netrc = _config->FindFile("Dir::Etc::netrc"); + if (netrc.empty() == false) + { + authconfs.emplace_back(new FileFd()); + authconfs.back()->Open(netrc, FileFd::ReadOnly); + } + + auto const netrcparts = _config->FindDir("Dir::Etc::netrcparts"); + if (netrcparts.empty() == false) + { + for (auto &&netrcpart : GetListOfFilesInDir(netrcparts, "conf", true, true)) + { + authconfs.emplace_back(new FileFd()); + authconfs.back()->Open(netrcpart, FileFd::ReadOnly); + } + } + _error->RevertToStack(); + + DropPrivsOrDie(); + + if (LoadSeccomp() == false) + return false; + + return true; + } + + bool MaybeAddAuthTo(URI &uri) + { + bool result = true; + + if (uri.User.empty() == false || uri.Password.empty() == false) + return true; + + _error->PushToStack(); + for (auto &authconf : authconfs) + { + if (authconf->IsOpen() == false) + continue; + if (authconf->Seek(0) == false) + { + result = false; + continue; + } + + result &= MaybeAddAuth(*authconf, uri); + } + + while (not _error->empty()) + { + std::string message; + _error->PopMessage(message); + Warning(std::move(message)); + } + _error->RevertToStack(); + + return result; + } + + aptAuthConfMethod(std::string &&Binary, char const *const Ver, unsigned long const Flags) APT_NONNULL(3) + : aptMethod(std::move(Binary), Ver, Flags) {} +}; +#endif |