modem: Migrate dump_modem.sh to rust

Test: adb bugreport
Bug: 286755695
Flag: EXEMPT refactor
Change-Id: I69b147263d423594a51904970ce5af05eff3b03b
Signed-off-by: Mahesh Kallelil <kallelil@google.com>
diff --git a/modem/dump_modemlog/Android.bp b/modem/dump_modemlog/Android.bp
index aca7b20..f509320 100644
--- a/modem/dump_modemlog/Android.bp
+++ b/modem/dump_modemlog/Android.bp
@@ -1,12 +1,12 @@
 package {
-    default_applicable_licenses: [ "Android-Apache-2.0" ],
+    default_applicable_licenses: ["Android-Apache-2.0"],
 }
 
-sh_binary {
-    name: "dump_modem.sh",
-    src: "dump_modem.sh",
+rust_binary {
+    name: "dump_modem",
+    srcs: ["dump_modem.rs"],
     vendor: true,
-    sub_dir: "dump",
+    relative_install_path: "dump",
 }
 
 // Modem Log Dumper
@@ -30,10 +30,10 @@
 
 cc_library {
     name: "modem_log_dumper",
-    srcs: [ "modem_log_dumper.cpp" ],
-    defaults: [ "modem_log_dumper_defaults" ],
+    srcs: ["modem_log_dumper.cpp"],
+    defaults: ["modem_log_dumper_defaults"],
     export_shared_lib_headers: modem_log_dumper_public_deps,
-    export_include_dirs: [ "include" ],
+    export_include_dirs: ["include"],
     vendor_available: true,
 }
 
@@ -41,7 +41,7 @@
 
 cc_binary {
     name: "dump_modemlog",
-    srcs: [ "dump_modemlog.cpp" ],
+    srcs: ["dump_modemlog.cpp"],
     cflags: [
         "-Wall",
         "-Wextra",
@@ -60,7 +60,7 @@
 
 cc_test {
     name: "dump_modemlog_test",
-    srcs: [ "modem_log_dumper_test.cpp" ],
+    srcs: ["modem_log_dumper_test.cpp"],
     defaults: [
         "modem_log_dumper_defaults",
         "modem_android_property_manager_fake_defaults",
diff --git a/modem/dump_modemlog/dump_modem.rs b/modem/dump_modemlog/dump_modem.rs
new file mode 100644
index 0000000..d9af7eb
--- /dev/null
+++ b/modem/dump_modemlog/dump_modem.rs
@@ -0,0 +1,109 @@
+// Copyright 2024 Google LLC
+
+//! The dump_modem binary is used to capture kernel/userspace logs in bugreport
+
+use std::fs;
+
+const MODEM_STAT: &str = "/data/vendor/modem_stat/debug.txt";
+const SSRDUMP_DIR: &str = "/data/vendor/ssrdump";
+const RFSD_ERR_LOG_DIR: &str = "/data/vendor/log/rfsd";
+const WAKEUP_EVENTS: &str = "/sys/devices/platform/cpif/wakeup_events";
+const CPIF_LOGBUFFER: &str = "/dev/logbuffer_cpif";
+const PCIE_EVENT_STATS: &str = "/sys/devices/platform/cpif/modem/pcie_event_stats";
+
+fn handle_io_error(file: &str, err: std::io::Error) {
+    match err.kind() {
+        std::io::ErrorKind::NotFound => println!("{file} not found!"),
+        std::io::ErrorKind::PermissionDenied => println!("Permission denied to access {file}"),
+        _ => println!("I/O error accessing {file}: {err}"),
+    }
+}
+
+fn print_file(file: &str) -> Result<(), std::io::Error> {
+    fs::metadata(file)?;
+
+    let data = fs::read_to_string(file)?;
+
+    if data.is_empty() {
+        println!("{file} is empty");
+    } else {
+        print!("{data}");
+    }
+
+    Ok(())
+}
+
+fn print_file_and_handle_error(file: &str) {
+    if let Err(err) = print_file(file) {
+        handle_io_error(file, err);
+    }
+}
+
+fn print_matching_files_in_dir(dir: &str, filename: &str) {
+    let Ok(entries) = fs::read_dir(dir) else {
+        return println!("Cannot open directory {dir}");
+    };
+
+    for entry in entries {
+        let Ok(entry) = entry else {
+            continue;
+        };
+        if entry.path().is_file() && entry.file_name().to_string_lossy().starts_with(filename) {
+            if let Some(path_str) = entry.path().to_str() {
+                println!("{}", path_str);
+                print_file_and_handle_error(path_str);
+            }
+        }
+    }
+}
+
+// Capture modem stat log if it exists
+fn modem_stat() {
+    println!("------ Modem Stat ------");
+    print_file_and_handle_error(MODEM_STAT);
+    println!();
+}
+
+// Capture crash signatures from all modem crashes
+fn modem_ssr_history() {
+    println!("------ Modem SSR history ------");
+    print_matching_files_in_dir(SSRDUMP_DIR, "crashinfo_modem");
+    println!();
+}
+
+// Capture rfsd error logs from all existing log files
+fn rfsd_error_log() {
+    println!("------ RFSD error log ------");
+    print_matching_files_in_dir(RFSD_ERR_LOG_DIR, "rfslog");
+    println!();
+}
+
+// Capture modem wakeup events if the sysfs attribute exists
+fn wakeup_events() {
+    println!("------ Wakeup event counts ------");
+    print_file_and_handle_error(WAKEUP_EVENTS);
+    println!();
+}
+
+// Capture kernel driver logbuffer if it exists
+fn cpif_logbuffer() {
+    println!("------ CPIF Logbuffer ------");
+    print_file_and_handle_error(CPIF_LOGBUFFER);
+    println!();
+}
+
+// Capture modem pcie stats if the sysfs attribute exists
+fn pcie_event_stats() {
+    println!("------ PCIe event stats ------");
+    print_file_and_handle_error(PCIE_EVENT_STATS);
+    println!();
+}
+
+fn main() {
+    modem_stat();
+    modem_ssr_history();
+    rfsd_error_log();
+    wakeup_events();
+    cpif_logbuffer();
+    pcie_event_stats();
+}
diff --git a/modem/dump_modemlog/dump_modem.sh b/modem/dump_modemlog/dump_modem.sh
deleted file mode 100644
index d1a535d..0000000
--- a/modem/dump_modemlog/dump_modem.sh
+++ /dev/null
@@ -1,41 +0,0 @@
-#!/vendor/bin/sh
-
-WAKEUP_EVENTS_FILE=/sys/devices/platform/cpif/wakeup_events
-CPIF_LOGBUFFER=/dev/logbuffer_cpif
-PCIE_EVENT_STATS=/sys/devices/platform/cpif/modem/pcie_event_stats
-
-echo "------ Modem Stat ------"
-cat /data/vendor/modem_stat/debug.txt
-
-echo "\n------ Modem SSR history ------"
-for f in $(ls /data/vendor/ssrdump/crashinfo_modem*); do
-  echo $f
-  cat $f
-done
-
-echo "\n------ RFSD error log ------"
-for f in $(ls /data/vendor/log/rfsd/rfslog_*); do
-  echo $f
-  cat $f
-done
-
-if [ -e $WAKEUP_EVENTS_FILE ]
-then
-  echo "\n------ Wakeup event counts ------"
-  echo $WAKEUP_EVENTS_FILE
-  cat $WAKEUP_EVENTS_FILE
-fi
-
-if [ -e $CPIF_LOGBUFFER ]
-then
-  echo "\n------ CPIF Logbuffer ------"
-  echo $CPIF_LOGBUFFER
-  cat $CPIF_LOGBUFFER
-fi
-
-if [ -e $PCIE_EVENT_STATS ]
-then
-  echo "\n------ PCIe event stats ------"
-  echo $PCIE_EVENT_STATS
-  cat $PCIE_EVENT_STATS
-fi
diff --git a/modem/dump_modemlog/dump_modemlog.mk b/modem/dump_modemlog/dump_modemlog.mk
index 5e91ab7..c96e729 100644
--- a/modem/dump_modemlog/dump_modemlog.mk
+++ b/modem/dump_modemlog/dump_modemlog.mk
@@ -1,5 +1,5 @@
 BOARD_VENDOR_SEPOLICY_DIRS += device/google/gs-common/modem/dump_modemlog/sepolicy
 
-PRODUCT_PACKAGES += dump_modem.sh
+PRODUCT_PACKAGES += dump_modem
 PRODUCT_PACKAGES += dump_modemlog
 
diff --git a/modem/dump_modemlog/sepolicy/file_contexts b/modem/dump_modemlog/sepolicy/file_contexts
index 29315e9..6d5c082 100644
--- a/modem/dump_modemlog/sepolicy/file_contexts
+++ b/modem/dump_modemlog/sepolicy/file_contexts
@@ -1,3 +1,3 @@
-/vendor/bin/dump/dump_modem\.sh      u:object_r:dump_modem_exec:s0
+/vendor/bin/dump/dump_modem          u:object_r:dump_modem_exec:s0
 /vendor/bin/dump/dump_modemlog       u:object_r:dump_modemlog_exec:s0