Merge remote-tracking branch 'origin/master' into flakes

2 files changed, 15 insertions, 0 deletions

diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index a9dab780f..f82f902fc 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -16,6 +16,7 @@
 #include <future>
 
 #include <fcntl.h>
+#include <grp.h>
 #include <limits.h>
 #include <pwd.h>
 #include <sys/ioctl.h>
@@ -1038,6 +1039,16 @@ void runProgram2(const RunOptions & options)
         if (source && dup2(in.readSide.get(), STDIN_FILENO) == -1)
             throw SysError("dupping stdin");
 
+        if (options.chdir && chdir((*options.chdir).c_str()) == -1)
+            throw SysError("chdir failed");
+        if (options.gid && setgid(*options.gid) == -1)
+            throw SysError("setgid failed");
+        /* Drop all other groups if we're setgid. */
+        if (options.gid && setgroups(0, 0) == -1)
+            throw SysError("setgroups failed");
+        if (options.uid && setuid(*options.uid) == -1)
+            throw SysError("setuid failed");
+
         Strings args_(options.args);
         args_.push_front(options.program);
 
diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index 09a90a340..35f9169f6 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -271,6 +271,9 @@ string runProgram(Path program, bool searchPath = false,
 
 struct RunOptions
 {
+    std::optional<uid_t> uid;
+    std::optional<uid_t> gid;
+    std::optional<Path> chdir;
     Path program;
     bool searchPath = true;
     Strings args;
@@ -427,6 +430,7 @@ void ignoreException();
 /* Some ANSI escape sequences. */
 #define ANSI_NORMAL "\e[0m"
 #define ANSI_BOLD "\e[1m"
+#define ANSI_FAINT "\e[2m"
 #define ANSI_RED "\e[31;1m"
 #define ANSI_GREEN "\e[32;1m"
 #define ANSI_BLUE "\e[34;1m"