allow adding local libraries

4 files changed, 125 insertions, 74 deletions

diff --git a/README.md b/README.md
index 2cafa8a..a6bbb8f 100644
--- a/README.md
+++ b/README.md
@@ -6,6 +6,10 @@ database:
 
     $ ./get
 
+You can also add a custom libc to your database.
+
+    $ ./add /usr/lib/libc-2.21.so
+
 Find all the libc's in the database that have a given name at the given address.
 Only the last 12 bits are checked, because randomization usually works on page
 size level.
diff --git a/add b/add
new file mode 100755
index 0000000..15c2abd
--- /dev/null
+++ b/add
@@ -0,0 +1,9 @@
+#!/bin/bash
+if [[ $# != 1 ]]; then
+  echo >&2 "Usage: $0 libc_filename"
+  exit 2
+fi
+
+. common/libc.sh
+
+add_local $1
diff --git a/common/libc.sh b/common/libc.sh
new file mode 100644
index 0000000..4d27b6d
--- /dev/null
+++ b/common/libc.sh
@@ -0,0 +1,111 @@
+#!/bin/bash
+
+mkdir -p tmp db
+
+die() {
+  echo >&2 $1
+  exit 1
+}
+
+dump_symbols() {
+  readelf -Ws $1 | perl -n -e '/: (\w*).*?(\w+)@@GLIBC_/ && print "$2 $1\n"'
+}
+
+extract_label() {
+  perl -n -e '/(\w+)/ && print $1'
+}
+
+dump_libc_start_main_ret() {
+  local call_main=`objdump -D $1 \
+    | grep -A 100 '<__libc_start_main>' \
+    | grep call \
+    | grep -B 1 '<exit>' \
+    | head -n 1 \
+    | extract_label`
+  local offset=`objdump -D $1 | egrep -A 1 "(^| )$call_main:" | tail -n 1 | extract_label`
+  if [[ "$offset" != "" ]]; then
+    echo "__libc_start_main_ret $offset"
+  fi
+}
+
+dump_bin_sh() {
+  local offset=`strings -a -t x $1 | grep '/bin/sh' | extract_label`
+  if [[ "$offset" != "" ]]; then
+    echo "str_bin_sh $offset"
+  fi
+}
+
+process_libc() {
+  local libc=$1
+  local id=$2
+  local info=$3
+  echo "  -> Writing libc to db/${id}.so"
+  cp $libc db/${id}.so
+  echo "  -> Writing symbols to db/${id}.symbols"
+  (dump_symbols $libc; dump_libc_start_main_ret $libc; dump_bin_sh $libc) \
+     > db/${id}.symbols
+  echo "  -> Writing version info"
+  echo "$info" > db/${id}.info
+}
+
+check_id() {
+  local id=$1
+  if [[ -e db/${id}.info ]]; then
+    echo "  -> Already have this version, 'rm db/${id}.*' to force"
+    return 1
+  fi
+  return 0
+}
+
+# ===== Ubuntu ===== #
+
+get_ubuntu() {
+  local url="$1"
+  local info="$2"
+  echo "Getting $info"
+  echo "  -> Location: $url"
+  local id=`echo $url | perl -n -e '/(libc6[^\/]*)\./ && print $1'`
+  echo "  -> ID: $id"
+  check_id $id || return
+  echo "  -> Downloading package"
+  rm -rf tmp/*
+  wget $url 2>/dev/null -O tmp/pkg.deb || die "Failed to download package from $url"
+  echo "  -> Extracting package"
+  cd tmp
+  ar x pkg.deb || die "ar failed"
+  tar xf data.tar.* || die "tar failed"
+  cd ..
+  local libc=`find tmp -name libc.so.6 || die "Cannot locate libc.so.6"`
+  process_libc $libc $id $info
+}
+
+get_current_ubuntu() {
+  local version=$1
+  local arch=$2
+  local pkg=$3
+  local info=ubuntu-$version-$arch-$pkg
+  echo "Getting package location for ubuntu-$version-$arch"
+  local url=`(wget http://packages.ubuntu.com/$version/$arch/$pkg/download -O - 2>/dev/null \
+               | grep -oh 'http://[^"]*libc6[^"]*.deb') || die "Failed to get package version"`
+  get_ubuntu $url $info
+}
+
+get_all_ubuntu() {
+  local info=$1
+  local url=$2
+  for f in `wget $url/ -O - 2>/dev/null | egrep -oh 'libc6(-i386|-amd64)?_[^"]*' |grep -v "</a>"`; do
+    get_ubuntu $url/$f $1
+  done
+}
+
+# ===== Local ===== #
+
+add_local() {
+  local libc=$1
+  [[ -e $libc ]] || return
+  local info="local"
+  local id="local-`sha1sum $libc`"
+  echo "Adding local libc $libc (id $id)"
+  check_id $id || return
+  process_libc $libc $id $info
+}
diff --git a/get b/get
index 9cb87bf..f723dce 100755
--- a/get
+++ b/get
@@ -1,78 +1,5 @@
 #!/bin/bash
-mkdir -p tmp db
-die() {
-  echo >&2 $1
-  exit 1
-}
-dump_symbols() {
-  readelf -Ws $1 | perl -n -e '/: (\w*).*?(\w+)@@GLIBC_/ && print "$2 $1\n"'
-}
-extract_label() {
-  perl -n -e '/(\w+)/ && print $1'
-}
-dump_libc_start_main_ret() {
-  local call_main=`objdump -D $1 \
-    | grep -A 100 '<__libc_start_main>' \
-    | grep call \
-    | grep -B 1 '<exit>' \
-    | head -n 1 \
-    | extract_label`
-  local offset=`objdump -D $1 | egrep -A 1 "(^| )$call_main:" | tail -n 1 | extract_label`
-  if [[ "$offset" != "" ]]; then
-    echo "__libc_start_main_ret $offset"
-  fi
-}
-dump_bin_sh() {
-  local offset=`strings -a -t x $1 | grep '/bin/sh' | extract_label`
-  if [[ "$offset" != "" ]]; then
-    echo "str_bin_sh $offset"
-  fi
-}
-get_ubuntu() {
-  local url="$1"
-  local info="$2"
-  echo "Getting $info"
-  echo "  -> Location: $url"
-  local id=`echo $url | perl -n -e '/(libc6[^\/]*)\./ && print $1'`
-  echo "  -> ID: $id"
-  if [[ -e db/${id}.info ]]; then
-    echo "  -> Already have this version, 'rm db/${id}.*' to force"
-    return
-  fi
-  echo "  -> Downloading package"
-  rm -rf tmp/*
-  wget $url 2>/dev/null -O tmp/pkg.deb || die "Failed to download package from $url"
-  echo "  -> Extracting package"
-  cd tmp
-  ar x pkg.deb || die "ar failed"
-  tar xf data.tar.* || die "tar failed"
-  cd ..
-  local libc=`find tmp -name libc.so.6 || die "Cannot locate libc.so.6"`
-  echo "  -> Writing libc to db/${id}.so"
-  cp $libc db/${id}.so
-  echo "  -> Writing symbols to db/${id}.symbols"
-  (dump_symbols $libc; dump_libc_start_main_ret $libc; dump_bin_sh $libc) \
-     > db/${id}.symbols
-  echo "  -> Writing version info"
-  echo "$info" > db/${id}.info
-}
-get_current_ubuntu() {
-  local version=$1
-  local arch=$2
-  local pkg=$3
-  local info=ubuntu-$version-$arch-$pkg
-  echo "Getting package location for ubuntu-$version-$arch"
-  local url=`(wget http://packages.ubuntu.com/$version/$arch/$pkg/download -O - 2>/dev/null \
-               | grep -oh 'http://[^"]*libc6[^"]*.deb') || die "Failed to get package version"`
-  get_ubuntu $url $info
-}
-get_all_ubuntu() {
-  local info=$1
-  local url=$2
-  for f in `wget $url/ -O - 2>/dev/null | egrep -oh 'libc6(-i386|-amd64)?_[^"]*' |grep -v "</a>"`; do
-    get_ubuntu $url/$f $1
-  done
-}
+. common/libc.sh
 
 get_current_ubuntu trusty i386 libc6
 get_current_ubuntu trusty amd64 libc6