logcat: filter based on UID
Bug: 153761317
Test: logging works normally without --uid
Test: logging filters based on uid with --uid
Change-Id: I6843fa635831c727c0236ac5534862e11447484b
diff --git a/logcat/logcat.cpp b/logcat/logcat.cpp
index 13023f2..0056c80 100644
--- a/logcat/logcat.cpp
+++ b/logcat/logcat.cpp
@@ -36,6 +36,7 @@
#include <memory>
#include <regex>
+#include <set>
#include <string>
#include <utility>
#include <vector>
@@ -358,6 +359,10 @@
-T '<time>' Print the lines since specified time (not imply -d).
count is pure numerical, time is 'MM-DD hh:mm:ss.mmm...'
'YYYY-MM-DD hh:mm:ss.mmm...' or 'sssss.mmm...' format.
+ --uid=<uids> Only display log messages from UIDs present in the comma separate list
+ <uids>. No name look-up is performed, so UIDs must be provided as
+ numeric values. This option is only useful for the 'root', 'log', and
+ 'system' users since only those users can view logs from other users.
)init");
fprintf(stderr, "\nfilterspecs are a series of \n"
@@ -535,6 +540,7 @@
size_t pid = 0;
bool got_t = false;
unsigned id_mask = 0;
+ std::set<uid_t> uids;
if (argc == 2 && !strcmp(argv[1], "--help")) {
show_help();
@@ -554,6 +560,7 @@
static const char id_str[] = "id";
static const char wrap_str[] = "wrap";
static const char print_str[] = "print";
+ static const char uid_str[] = "uid";
// clang-format off
static const struct option long_options[] = {
{ "binary", no_argument, nullptr, 'B' },
@@ -581,6 +588,7 @@
{ "statistics", no_argument, nullptr, 'S' },
// hidden and undocumented reserved alias for -t
{ "tail", required_argument, nullptr, 't' },
+ { uid_str, required_argument, nullptr, 0 },
// support, but ignore and do not document, the optional argument
{ wrap_str, optional_argument, nullptr, 0 },
{ nullptr, 0, nullptr, 0 }
@@ -631,6 +639,17 @@
if (long_options[option_index].name == id_str) {
setId = (optarg && optarg[0]) ? optarg : nullptr;
}
+ if (long_options[option_index].name == uid_str) {
+ auto uid_strings = Split(optarg, delimiters);
+ for (const auto& uid_string : uid_strings) {
+ uid_t uid;
+ if (!ParseUint(uid_string, &uid)) {
+ error(EXIT_FAILURE, 0, "Unable to parse UID '%s'", uid_string.c_str());
+ }
+ uids.emplace(uid);
+ }
+ break;
+ }
break;
case 's':
@@ -1164,6 +1183,10 @@
LOG_ID_MAX);
}
+ if (!uids.empty() && uids.count(log_msg.entry.uid) == 0) {
+ continue;
+ }
+
PrintDividers(log_msg.id(), printDividers);
if (print_binary_) {
diff --git a/logcat/tests/logcat_test.cpp b/logcat/tests/logcat_test.cpp
index f3fdfd7..a2daeb0 100644
--- a/logcat/tests/logcat_test.cpp
+++ b/logcat/tests/logcat_test.cpp
@@ -16,6 +16,7 @@
#include <ctype.h>
#include <dirent.h>
+#include <pwd.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
@@ -28,10 +29,12 @@
#include <unistd.h>
#include <memory>
+#include <regex>
#include <string>
#include <android-base/file.h>
#include <android-base/macros.h>
+#include <android-base/parseint.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <gtest/gtest.h>
@@ -1748,3 +1751,83 @@
ASSERT_TRUE(android::base::StartsWith(output, "unknown buffer foo\n"));
}
+
+static void SniffUid(const std::string& line, uid_t& uid) {
+ auto uid_regex = std::regex{"\\S+\\s+\\S+\\s+(\\S+).*"};
+
+ auto trimmed_line = android::base::Trim(line);
+
+ std::smatch match_results;
+ ASSERT_TRUE(std::regex_match(trimmed_line, match_results, uid_regex))
+ << "Unable to find UID in line '" << trimmed_line << "'";
+ auto uid_string = match_results[1];
+ if (!android::base::ParseUint(uid_string, &uid)) {
+ auto pwd = getpwnam(uid_string.str().c_str());
+ ASSERT_NE(nullptr, pwd) << "uid '" << uid_string << "' in line '" << trimmed_line << "'";
+ uid = pwd->pw_uid;
+ }
+}
+
+static void UidsInLog(std::optional<std::vector<uid_t>> filter_uid, std::map<uid_t, size_t>& uids) {
+ std::string command;
+ if (filter_uid) {
+ std::vector<std::string> uid_strings;
+ for (const auto& uid : *filter_uid) {
+ uid_strings.emplace_back(std::to_string(uid));
+ }
+ command = android::base::StringPrintf(logcat_executable
+ " -v uid -b all -d 2>/dev/null --uid=%s",
+ android::base::Join(uid_strings, ",").c_str());
+ } else {
+ command = logcat_executable " -v uid -b all -d 2>/dev/null";
+ }
+ auto fp = std::unique_ptr<FILE, decltype(&pclose)>(popen(command.c_str(), "r"), pclose);
+ ASSERT_NE(nullptr, fp);
+
+ char buffer[BIG_BUFFER];
+ while (fgets(buffer, sizeof(buffer), fp.get())) {
+ // Ignore dividers, e.g. '--------- beginning of radio'
+ if (android::base::StartsWith(buffer, "---------")) {
+ continue;
+ }
+ uid_t uid;
+ SniffUid(buffer, uid);
+ uids[uid]++;
+ }
+}
+
+static std::vector<uid_t> TopTwoInMap(const std::map<uid_t, size_t>& uids) {
+ std::pair<uid_t, size_t> top = {0, 0};
+ std::pair<uid_t, size_t> second = {0, 0};
+ for (const auto& [uid, count] : uids) {
+ if (count > top.second) {
+ top = second;
+ top = {uid, count};
+ } else if (count > second.second) {
+ second = {uid, count};
+ }
+ }
+ return {top.first, second.first};
+}
+
+TEST(logcat, uid_filter) {
+ std::map<uid_t, size_t> uids;
+ UidsInLog({}, uids);
+
+ ASSERT_GT(uids.size(), 2U);
+ auto top_uids = TopTwoInMap(uids);
+
+ // Test filtering with --uid=<top uid>
+ std::map<uid_t, size_t> uids_only_top;
+ std::vector<uid_t> top_uid = {top_uids[0]};
+ UidsInLog(top_uid, uids_only_top);
+
+ EXPECT_EQ(1U, uids_only_top.size());
+
+ // Test filtering with --uid=<top uid>,<2nd top uid>
+ std::map<uid_t, size_t> uids_only_top2;
+ std::vector<uid_t> top2_uids = {top_uids[0], top_uids[1]};
+ UidsInLog(top2_uids, uids_only_top2);
+
+ EXPECT_EQ(2U, uids_only_top2.size());
+}