From 05ef357e575e9c25eb6a35cb693d1eb19bb14d45 Mon Sep 17 00:00:00 2001
From: David Kalnischkies <david@kalnischkies.de>
Date: Fri, 18 Sep 2015 11:14:56 +0200
Subject: refactor dpkg execution in deb/debsystem
We have a few places and there will be a few more still where we have to
call dpkg to detect/set certain features or settings. Centralizing the
calling infrastructure now seems like a good idea before we add another.
---
apt-pkg/deb/debsystem.cc | 108 ++++++++++++++++++++++++++---------------------
1 file changed, 61 insertions(+), 47 deletions(-)
(limited to 'apt-pkg/deb')
diff --git a/apt-pkg/deb/debsystem.cc b/apt-pkg/deb/debsystem.cc
index 724312bc5..d6ef49a37 100644
--- a/apt-pkg/deb/debsystem.cc
+++ b/apt-pkg/deb/debsystem.cc
@@ -302,30 +302,62 @@ void debSystem::DpkgChrootDirectory() /*{{{*/
_exit(100);
}
/*}}}*/
-bool debSystem::SupportsMultiArch() /*{{{*/
+static pid_t ExecDpkg(std::vector<std::string> const &sArgs, int * const inputFd, int * const outputFd, bool const showStderr)/*{{{*/
{
- std::vector<std::string> const Args = GetDpkgBaseCommand();
- std::vector<const char *> cArgs(Args.size(), NULL);
- std::transform(Args.begin(), Args.end(), cArgs.begin(), [](std::string const &s) { return s.c_str(); });
+ std::vector<const char *> Args(sArgs.size(), NULL);
+ std::transform(sArgs.begin(), sArgs.end(), Args.begin(), [](std::string const &s) { return s.c_str(); });
+ Args.push_back(NULL);
- // we need to detect if we can qualify packages with the architecture or not
- cArgs.push_back("--assert-multi-arch");
- cArgs.push_back(NULL);
+ int external[2] = {-1, -1};
+ if (inputFd != nullptr || outputFd != nullptr)
+ if (pipe(external) != 0)
+ {
+ _error->WarningE("dpkg", "Can't create IPC pipe for dpkg call");
+ return -1;
+ }
- pid_t dpkgAssertMultiArch = ExecFork();
- if (dpkgAssertMultiArch == 0)
- {
- DpkgChrootDirectory();
- // redirect everything to the ultimate sink as we only need the exit-status
+ pid_t const dpkg = ExecFork();
+ if (dpkg == 0) {
int const nullfd = open("/dev/null", O_RDONLY);
- dup2(nullfd, STDIN_FILENO);
- dup2(nullfd, STDOUT_FILENO);
- dup2(nullfd, STDERR_FILENO);
- execvp(cArgs[0], (char**) &cArgs[0]);
- _error->WarningE("dpkgGo", "Can't detect if dpkg supports multi-arch!");
- _exit(2);
+ if (inputFd == nullptr)
+ dup2(nullfd, STDIN_FILENO);
+ else
+ {
+ close(external[1]);
+ dup2(external[0], STDIN_FILENO);
+ }
+ if (outputFd == nullptr)
+ dup2(nullfd, STDOUT_FILENO);
+ else
+ {
+ close(external[0]);
+ dup2(external[1], STDOUT_FILENO);
+ }
+ if (showStderr == false)
+ dup2(nullfd, STDERR_FILENO);
+ debSystem::DpkgChrootDirectory();
+ execvp(Args[0], (char**) &Args[0]);
+ _error->WarningE("dpkg", "Can't execute dpkg!");
+ _exit(100);
}
-
+ if (outputFd != nullptr)
+ {
+ close(external[1]);
+ *outputFd = external[0];
+ }
+ else if (inputFd != nullptr)
+ {
+ close(external[0]);
+ *inputFd = external[1];
+ }
+ return dpkg;
+}
+ /*}}}*/
+bool debSystem::SupportsMultiArch() /*{{{*/
+{
+ std::vector<std::string> Args = GetDpkgBaseCommand();
+ Args.push_back("--assert-multi-arch");
+ pid_t const dpkgAssertMultiArch = ExecDpkg(Args, nullptr, nullptr, false);
if (dpkgAssertMultiArch > 0)
{
int Status = 0;
@@ -344,39 +376,21 @@ bool debSystem::SupportsMultiArch() /*{{{*/
/*}}}*/
std::vector<std::string> debSystem::SupportedArchitectures() /*{{{*/
{
- std::vector<std::string> const sArgs = GetDpkgBaseCommand();
- std::vector<const char *> Args(sArgs.size(), NULL);
- std::transform(sArgs.begin(), sArgs.end(), Args.begin(), [](std::string const &s) { return s.c_str(); });
- Args.push_back("--print-foreign-architectures");
- Args.push_back(NULL);
-
std::vector<std::string> archs;
- string const arch = _config->Find("APT::Architecture");
- if (arch.empty() == false)
- archs.push_back(arch);
-
- int external[2] = {-1, -1};
- if (pipe(external) != 0)
{
- _error->WarningE("getArchitecture", "Can't create IPC pipe for dpkg --print-foreign-architectures");
- return archs;
+ string const arch = _config->Find("APT::Architecture");
+ if (arch.empty() == false)
+ archs.push_back(std::move(arch));
}
- pid_t dpkgMultiArch = ExecFork();
- if (dpkgMultiArch == 0) {
- close(external[0]);
- int const nullfd = open("/dev/null", O_RDONLY);
- dup2(nullfd, STDIN_FILENO);
- dup2(external[1], STDOUT_FILENO);
- dup2(nullfd, STDERR_FILENO);
- DpkgChrootDirectory();
- execvp(Args[0], (char**) &Args[0]);
- _error->WarningE("getArchitecture", "Can't detect foreign architectures supported by dpkg!");
- _exit(100);
- }
- close(external[1]);
+ std::vector<std::string> sArgs = GetDpkgBaseCommand();
+ sArgs.push_back("--print-foreign-architectures");
+ int outputFd = -1;
+ pid_t const dpkgMultiArch = ExecDpkg(sArgs, nullptr, &outputFd, false);
+ if (dpkgMultiArch == -1)
+ return archs;
- FILE *dpkg = fdopen(external[0], "r");
+ FILE *dpkg = fdopen(outputFd, "r");
if(dpkg != NULL) {
char* buf = NULL;
size_t bufsize = 0;
--
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