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Klein Panic
2025-10-22 05:04:19 -04:00
parent 10e8dfba2d
commit fab5470d6c
4 changed files with 383 additions and 193 deletions
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10
Makefile
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@@ -13,6 +13,12 @@ ISSUE_DIR ?= system/issue
ISSUE_FILE ?= $(ISSUE_DIR)/issue.fblogin
ISSUE_DEST ?= /etc/issue.fblogin
# Manpage install defaults
MANPREFIX ?= $(PREFIX)/share/man
MAN1DIR ?= $(MANPREFIX)/man1
MAN1PAGES ?= man/fblogin.1
MAN1NAME := $(notdir $(MAN1PAGES))
# Compiler/Linker
CC := gcc
CPPFLAGS := -I$(INC_DIR) -D_GNU_SOURCE -MMD -MP
@@ -86,7 +92,7 @@ install-man:
install -m 0644 $(MAN1PAGES) $(DESTDIR)$(MAN1DIR)/
@# gzip if available, keep original if not
@if command -v gzip >/dev/null 2>&1; then \
gzip -9nf $(DESTDIR)$(MAN1DIR)/fblogin.1; \
gzip -9nf $(DESTDIR)$(MAN1DIR)/$(MAN1NAME); \
fi
# Convenience: install everything we ship
@@ -107,7 +113,7 @@ uninstall-issue:
rm -f $(DESTDIR)$(ISSUE_DEST)
uninstall-man:
rm -f $(DESTDIR)$(MAN1DIR)/fblogin.1 $(DESTDIR)$(MAN1DIR)/fblogin.1.gz
rm -f $(DESTDIR)$(MAN1DIR)/$(MAN1NAME) $(DESTDIR)$(MAN1DIR)/$(MAN1NAME).gz
uninstall-all: uninstall uninstall-systemd uninstall-pam uninstall-issue uninstall-man

500
README.md
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@@ -1,236 +1,356 @@
# fblogin: Framebuffer-Based Graphical Login for Debian
/¯¯¯¯/\¯¯¯¯\·. ''/¯¯¯¯/\¯¯¯¯\·. |¯¯¯¯|`·.' '/¯¯¯¯/\¯¯¯¯\`·.''/¯¯¯¯/\¯¯¯¯\·. |¯¯¯¯|`·.'/¯¯¯¯/`·.
|`·.·´`·|::'¯¯¯¯`·.\|·´`·.·´|:/____/`·.|`·.·´`·|:::' |·´`·.·´|::|`·.·´`·|:::|`·.·´`·|:::¯¯¯¯`·.\|.·´`·.·|:::|.·´`·.·|\¯¯¯¯\`·.
|`·.·´`·|\¯¯¯¯\·.¨ '|·´`·.·´|:\¯¯¯¯\·./|`·.·´`·|::|¯¯¯¯|`·.|·´`·.·´|::|`·.·´`·|:::|`·.·´`·|:\¯¯¯¯\·. ¨|.·´`·.·|:::|.·´`·.·|:|`·.·´`·|:::'
|____|::¯¯¯¯`·.\''\____\/____/`·.'\____\/____/`·.''\____\/____/`·.''\____\/____/`·. |____|:::|____|:|____|:::'
'`·.:::::`·.¨ ¨ ¨ ¨ ¨ ' `·.::::::::::::'`·./ `·.::::::::::::'`·./' '`·.:::::::::::::`·./' `·.::::::::::::'`·./ '`·.:::::`·.'`·.:::::`·`·.::::`·.
## **Introduction**
# fblogin — framebuffer login for tty1
fblogin is a **lightweight, framebuffer-based graphical login manager** designed for Debian systems. It replaces the standard tty1 login prompt with a visually enhanced interface utilizing the **Linux framebuffer** for graphics, **PAM** for authentication, and optional **fingerprint verification via fprintd**. The system supports:
- **Direct framebuffer rendering** for a graphical login screen without X11/Wayland.
- **Pluggable Authentication Modules (PAM)** for authentication.
- **Fingerprint authentication** using `fprintd`.
- **Raw terminal input processing** for an interactive TUI-style experience.
- **Minimal system overhead**, replacing `getty` via `systemd` overrides.
This document provides an exhaustive technical breakdown of `fblogin`, covering **system dependencies, low-level memory operations, device interactions, authentication flow, and graphical rendering.**
## Note
> If you use ubuntu run at ur own risk.
Framebuffer greeter that:
- draws directly to **fbdev** (no X/Wayland),
- authenticates via **PAM** (optional fprintd),
- binds a **logind** session on **tty1**,
- execs a **real login shell** on the same VT.
---
## **System Dependencies**
## Quick start
### **1. Required Header Files**
```bash
# Debian/Ubuntu deps
sudo apt-get install -y build-essential libpam0g-dev libfprint-dev fprintd pkg-config
`fblogin` requires both **standard C libraries** and **Linux-specific headers** for framebuffer and authentication control.
#### **Standard Libraries:**
- `<stddef.h>` – Defines `size_t` and other fundamental types.
- `<stdint.h>` – Fixed-width integer types.
- `<stdio.h>` – Input/output functions.
- `<stdlib.h>` – Memory allocation, system functions.
- `<string.h>` – String handling utilities.
- `<time.h>` – Timing functions.
#### **System-Level Libraries:**
- `<unistd.h>` – Low-level system calls.
- `<sys/ioctl.h>` – Device communication.
- `<sys/mman.h>` – Memory mapping (`mmap`).
- `<sys/types.h>` – Defines `pid_t`, `uid_t`, etc.
- `<sys/wait.h>` – Process synchronization (`waitpid`).
#### **Framebuffer Graphics:**
- `<linux/fb.h>` – Framebuffer device control.
- `"fb.h"` – Custom framebuffer manipulation.
- `"font8x8_basic.h"` – Bitmap font rendering.
#### **Authentication and User Management:**
- `<security/pam_appl.h>` – PAM API for authentication.
- `"pam_auth.h"` – Custom PAM authentication handler.
- `<pwd.h>` – User account management.
- `<grp.h>` – Group management.
#### **Terminal Input Handling:**
- `<termios.h>` – Raw keyboard input control.
- `"input.h"` – Custom keyboard processing.
#### **Process and Signal Management:**
- `<signal.h>` – Signal handling.
- `"ui.h"` – User interface logic.
### **2. System Calls Used**
The core functionality of `fblogin` relies on direct **syscalls** for process control, user authentication, and framebuffer manipulation.
#### **File and Memory Operations:**
- `open()` – Opens `/dev/fb0`.
- `read()` – Reads user input.
- `close()` – Closes descriptors.
- `mmap()` – Maps framebuffer memory.
- `munmap()` – Unmaps memory.
#### **Process Control:**
- `fork()` – Creates login subprocess.
- `waitpid()` – Waits for completion.
- `setsid()` – Creates a new session (daemon-like behavior).
#### **User and Permission Management:**
- `setuid()` – Changes user ID.
- `setgid()` – Changes group ID.
- `getuid()` – Retrieves user ID.
#### **Framebuffer Operations:**
- `ioctl()` – Direct framebuffer control.
#### **Authentication & Fingerprint Handling:**
- `pam_*` – PAM API functions.
- `fprintd-verify` – Fingerprint authentication via `fprintd`.
---
## Setup and Installation
1. **Clone or Download the repo**:
```Bash
git clone https://github.com/yourusername/fblogin.git
cd fblogin
```
2. **Install required Dependencies**:
on Debian you might install PAM and fprintd with:
```Bash
sudo apt-get update
sudo apt-get install libpam0g-dev fprintd libfprint-dev
```
3. **Build the project**
The project comes with a make file and a bash script
```Bash
# build + install (binary, unit, pam, banner, manpage)
make
sudo make install-all
# logging (global file, debug on)
sudo install -d -m 0755 /var/log/fblogin
sudo install -m 0640 /dev/null /var/log/fblogin/fblogin.log
sudo chown root:adm /var/log/fblogin/fblogin.log
# unit env (drop-in)
sudo systemctl edit fblogin@tty1.service
# [Service]
# Environment=FBLOGIN_DEBUG=1
# Environment=FBLOGIN_LOG_FILE=/var/log/fblogin/fblogin.log
# logrotate (SIGUSR1 reopen)
sudo tee /etc/logrotate.d/fblogin >/dev/null <<'ROT'
/var/log/fblogin/fblogin.log {
rotate 7
daily
missingok
notifempty
compress
create 0640 root adm
postrotate
systemctl kill -s SIGUSR1 fblogin@tty1.service 2>/dev/null || true
endscript
}
ROT
sudo systemctl daemon-reload
sudo systemctl enable --now fblogin@tty1.service
```
For direct installation
```Bash
make install
```
For uninstallation
```Bash
make uninstall
```
4. Ensure your computer environment is propely setup
```Bash
./setup.sh
```
### Note
> Please create issues if any of these steps produce errors
> For your consideration: The program should be ran as root because it needs access to /dev/fb0 but ultimately it is designed to be ran by systemd
> For your consideration: The program has a strict isolation aspect that limits the running of this program to /dev/tty1 only. This can be changed in the code base to be a different tty or entirely commented out to run on all ttys and truly override the login command for your entire computer (NOT RECOMMENDED. THIS CODE IS STILL IN DEVELOPMENT).
Switch to tty1, log in (fingerprint or password). You land in a login shell on tty1; start your session from there (e.g., `startx`).
---
## Usage
1. **Switch to TTY1:**
fblogin is configured to run only on /dev/tty1. You can switch to tty1 with:
## Contents
```bash
Ctrl+Alt+F1
- [Scope](#scope)
- [Features](#features)
- [Repository layout](#repository-layout)
- [Build/install targets](#buildinstall-targets)
- [Systemd integration](#systemd-integration)
- [PAM stack](#pam-stack)
- [Authentication flow](#authentication-flow)
- [Session model](#session-model)
- [TTY/signals](#ttysignals)
- [Logging modes](#logging-modes)
- [Xauthority/startx notes](#xauthoritystartx-notes)
- [setup.sh](#setupsh)
- [Man page](#man-page)
- [Security](#security)
- [Troubleshooting](#troubleshooting)
- [Contributing / License / Docs](#contributing--license--docs)
---
## Scope
**Is**
- Greeter for **tty1** using fbdev.
- PAM client that opens a proper **logind** session.
- Hands control to a login shell; session startup remains user-controlled.
**Is not**
- Full display manager (no seat juggling, no VT switching).
- Compositor or X/Wayland launcher.
- Aggressive manager of `.Xauthority` (guidance only).
---
## Features
- **Env-aware logging**
- `FBLOGIN_DEBUG=1` toggles debug.
- `FBLOGIN_LOG_FILE=…` pins a global log file (no per-user switch).
- `SIGUSR1` reopens the forced log (for logrotate).
- **CLI**
- `--help`, `--version` (from `include/version.h`)
- `--log-file=/path` (implies debug; pins logging)
- `--no-fp`, `--fp-max=N` (UI hint; PAM remains authoritative)
- `--dev` (relax in-session guard), `--debug`
- **Greeter keeper**
- Greeter PAM session in a child, held open until auth, then closed.
- **sd-login diagnostics** (if linked with libsystemd)
- **Self-pipe signal wakeups** (no SA_RESTART surprises)
---
## Repository layout
```
include/
config.h fb.h input.h pam_auth.h ui.h version.h
man/
fblogin.1
src/
fb.c input.c pam_auth.c ui.c main.c
system/
systemd/fblogin@.service
pamd/fblogin
issue/issue.fblogin
docs/
ARCHITECTURE.md CHANGELOG.md Contributing.md TODO.md
Makefile
setup.sh
README.md
```
2. **Run fblogin as Root:**
```bash
sudo ./fblogin
```
---
3. **Login Process:**
* Username Entry:
* The login screen initially displays an input field for the username. Type your username.
* Toggle Fields with Tab:
* Press Tab to switch between the username and password fields.
* Fingerprint Authentication:
* If a fingerprint reader is detected (fprintd-list is available), the program will attempt fingerprint authentication as soon as the username is entered.
* If fingerprint authentication fails, it falls back to the password entry.
* Password Entry:
* When editing the password field, type your password and press Enter to authenticate.
* Ctrl‑D:
* Pressing Ctrl‑D will clear both fields and restart the login prompt.
* Post-Authentication:
* On successful authentication, fblogin will adjust tty permissions, set environment variables (such as HOME, USER, SHELL), and then launch the user's shell as a login shell.
## Build/install targets
### Troubleshooting
Variables:
- `PREFIX=/usr/local` (default)
- `BINDIR=$(PREFIX)/bin`
- `MANPREFIX=$(PREFIX)/share/man`, `MAN1DIR=$(MANPREFIX)/man1`
- `ISSUE_FILE=system/issue/issue.fblogin`
1. Framebuffer Initialization:
If you encounter an error initializing the framebuffer (/dev/fb0), ensure your user has the correct permissions or that the framebuffer device exists.
Targets:
```make
make # build
make debug|release|asan
2. Input Device Issues:
If no input is detected, verify that the keyboard input library is properly set up and that /dev/tty1 is active.
sudo make install # binary (4755)
sudo make install-systemd # unit
sudo make install-pam # /etc/pam.d/fblogin
sudo make install-issue # /etc/issue.fblogin (optional)
sudo make install-man # manpage
sudo make install-all # all above
3. Fingerprint Reader Issues:
Make sure that fprintd-list and fprintd-verify are installed, executable, and that your fingerprint sensor is supported by the fprintd library.
sudo make uninstall
sudo make uninstall-systemd
sudo make uninstall-pam
sudo make uninstall-issue
sudo make uninstall-man
sudo make uninstall-all
```
Uninstall is symmetric with defaults. If you changed `PREFIX`/`MAN*`, pass the same values to uninstall.
---
## **System Architecture**
## Systemd integration
### **1. Authentication Flow (PAM + fprintd)**
Installed unit (`system/systemd/fblogin@.service`):
1. The program **initializes PAM** with `pam_start("fblogin", username, &conv, &pamh)`.
2. If **fingerprint authentication is enabled**, `fprintd-list` checks for stored fingerprints.
3. If **a fingerprint is found**, `fprintd-verify` is called and its output determines success.
4. If **fingerprint authentication fails**, the system **falls back to password login**.
5. Upon successful authentication, `pam_acct_mgmt()` verifies **account validity**.
6. If approved, `pam_open_session()` starts a session and `execv()` spawns the user's shell.
```ini
[Unit]
Description=Framebuffer Login on %I
Documentation=man:systemd-logind.service(8) man:logind.conf(5)
After=systemd-user-sessions.service plymouth-quit-wait.service
Conflicts=getty@%i.service
ConditionPathExists=/dev/%I
### **2. Framebuffer Rendering Pipeline**
[Service]
TTYPath=/dev/%I
TTYReset=yes
TTYVHangup=yes
StandardInput=tty
StandardOutput=tty
StandardError=tty
1. The framebuffer device `/dev/fb0` is **opened with `open()`**.
2. `ioctl(FBIOGET_VSCREENINFO)` retrieves **display dimensions**.
3. `mmap()` maps framebuffer memory for **direct pixel access**.
4. The screen is **cleared to black** using `memset()`.
5. An **8×8 bitmap font** is rendered with `font8x8_basic.h` and **scaling factors**.
6. The **Debian logo (PFP) is drawn at the center** using per-pixel transformations.
7. The **cmatrix animation (if enabled) updates the background** dynamically.
PAMName=fblogin
UtmpIdentifier=%I
UtmpMode=user
### **3. Terminal Input Handling**
ExecStart=/usr/local/bin/fblogin
Type=simple
Restart=always
RestartSec=1
1. `termios` switches tty **to raw mode** (`ECHO` and `ICANON` disabled).
2. Keypresses are read **one character at a time** using `read()`.
3. **Backspace is handled manually** by clearing screen regions.
4. On `Enter`, the input is **validated and passed to PAM**.
5. If **Ctrl+C is pressed**, `fblogin` exits immediately.
[Install]
WantedBy=multi-user.target
```
### **4. System Integration (Replacing getty via systemd)**
Recommended drop-in:
1. `fblogin` replaces `getty` using a **systemd override**:
```ini
[Service]
ExecStart=/usr/local/bin/fblogin
```
2. `setsid()` ensures `fblogin` runs as a **session leader**.
3. After login, `execv()` **spawns the user shell** (e.g., `/bin/bash`).
```ini
[Service]
Environment=FBLOGIN_DEBUG=1
Environment=FBLOGIN_LOG_FILE=/var/log/fblogin/fblogin.log
```
Logrotate:
```conf
/var/log/fblogin/fblogin.log {
rotate 7
daily
missingok
notifempty
compress
create 0640 root adm
postrotate
systemctl kill -s SIGUSR1 fblogin@tty1.service 2>/dev/null || true
endscript
}
```
---
## **Security Considerations**
## PAM stack
- **Direct framebuffer access** is only possible for root; `fblogin` runs with **setuid-root**.
- **PAM sessions are properly closed** via `pam_close_session()`.
- **No passwords are stored**; authentication is handled via PAM modules.
- **SIGINT/SIGTERM handling** ensures graceful exit.
`/etc/pam.d/fblogin`:
```
auth include common-auth
account include common-account
password include common-password
session required pam_env.so
session required pam_loginuid.so
session include common-session
session required pam_systemd.so
```
- `pam_loginuid.so` sets `/proc/self/loginuid`.
- `pam_systemd.so` registers the session with logind.
---
## **Future Improvements**
## Authentication flow
- **Dynamic resolution scaling** (currently, framebuffer dimensions are fixed at launch).
- **DRM/KMS support** to replace **legacy fbdev**.
- **Enhanced cmatrix animations** with smoother transitions.
- Username field first; `Tab` toggles focus.
- If password is empty and fingerprints are enabled, try the **fingerprint** path via PAM.
- On success: welcome screen → stop greeter keeper → exec user’s login shell.
- On failure: prompt for password and proceed via PAM.
Disable fingerprints:
- `--no-fp` or `FBLOGIN_FINGERPRINT=0`.
---
## **Conclusion**
## Session model
`fblogin` is a **high-performance framebuffer-based login manager** that integrates with PAM authentication and fingerprint recognition. It is a lightweight alternative to graphical login managers, optimized for minimalism and direct hardware interaction.
- Runs on **tty1** (`TTYPath` + `UtmpMode=user`).
- Opens the user **PAM** session; logind sees `CLASS=user TYPE=tty`.
- Drops to user’s uid/gid, sets `HOME/SHELL/USER/LOGNAME` (+ fallback `PATH`), execs the login shell with `-l`.
- Start the graphical session from that shell (e.g., `startx`).
---
## TTY/signals
- `SIGTERM`: graceful shutdown via self-pipe to break `poll(2)`.
- `SIGUSR1`: reopen forced log file.
- `SIGINT`, `SIGQUIT`, `SIGTSTP`: ignored.
Keys:
- `Tab` toggle focus, `Ctrl-U` clear focused field, `Ctrl-R` reset both, `Ctrl-D` restart greeter UI.
---
## Logging modes
- **Default**: pre-user logs to `/tmp/fblogin-$pid.log`; after username known, switch to `$HOME/.fblogin.log` (600, chowned).
- **Forced global**: set `FBLOGIN_LOG_FILE=/var/log/fblogin/fblogin.log` or pass `--log-file=/path`. Remains on that file and never switches. `SIGUSR1` triggers reopen. Requires `FBLOGIN_DEBUG=1` or `--debug` (implied by `--log-file`).
---
## Xauthority/startx notes
Do not export `XAUTHORITY` globally in `~/.zshenv`.
If keeping Xauthority under `XDG_RUNTIME_DIR` **only on tty1**, add to `~/.config/zsh/.zlogin`:
```zsh
if [[ -z "$DISPLAY" && -z "$SSH_TTY" && "$(tty)" == "/dev/tty1" ]]; then
if [[ -n "$XDG_RUNTIME_DIR" && -O "$XDG_RUNTIME_DIR" ]]; then
AUTH="${XDG_RUNTIME_DIR}/x11/Xauthority"
install -d -m 700 -- "${AUTH:h}"
if [[ ! -L "$HOME/.Xauthority" || "$(readlink -f "$HOME/.Xauthority" 2>/dev/null)" != "$AUTH" ]]; then
rm -f -- "$HOME/.Xauthority"
ln -s -- "$AUTH" "$HOME/.Xauthority"
fi
# exec startx # optional
fi
fi
```
`~/.xinitrc` should not hard-set `XAUTHORITY`; let `xinit/xauth` manage cookies. It can export env to user services if needed.
---
## setup.sh
Automates:
- PAM file write,
- unit install,
- removal of conflicting `getty@tty1` override,
- disabling getty on tty1/tty2,
- enabling `fblogin@tty1`,
- basic verification.
Run with root: `sudo ./setup.sh`.
---
## Man page
Install via `make install-man`, then `man fblogin`.
---
## Security
- Binary is **setuid root** (4755).
- PAM handles credentials; we don’t store them.
- Greeter session isolated; user session opened/closed explicitly.
- Minimal signal surface; blocking calls interrupted safely.
---
## Troubleshooting
- **stdin is not a TTY**: start via `fblogin@tty1.service` on a VT.
- **PAM session failed (TTY busy / inside a session)**: use a free VT; don’t launch inside an existing session unless `--dev`.
- **polkit prompts missing**: ensure DE/WM started from the tty-backed session (`loginctl` should show `TYPE=tty`).
- **fingerprint never matches**: enroll with `fprintd-enroll`, confirm sensor support; disable with `--no-fp` if needed.
- **logs break after rotation**: use the provided logrotate and `SIGUSR1` reopen; ensure forced global logging is configured.
- **no /dev/fb0**: fbdev not exposed; current code targets fbdev, not DRM/KMS.
---
## Contributing / License / Docs
- Contribution guide: `docs/Contributing.md`
- Architecture notes: `docs/ARCHITECTURE.md`
- Changelog: `docs/CHANGELOG.md`
- License: `LICENSE`

3
docs/TODO.md
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@@ -3,3 +3,6 @@
## Priority 1:
Security audit
Add release
Add OS multi support

63
src/main.c
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@@ -31,6 +31,10 @@
#include <systemd/sd-login.h>
#endif
/* forward decls */
static void print_help(const char *argv0);
static void print_version(void);
/* ---------- debug logger ---------- */
static FILE *g_log = NULL;
static int debug_enabled = 0;
@@ -38,7 +42,7 @@ static char g_log_path[512] = {0};
/* when nonzero, we pin logs to a specific file and never switch to per-user */
static int g_log_forced = 0;
static char g_log_forced_path[512] = {0};
static void log_reopen_if_forced(void);
static void ts_now(char *buf, size_t n) {
#if FBLOGIN_LOG_TIMESTAMP
@@ -68,6 +72,18 @@ static void dlog(const char *fmt, ...) {
va_end(ap);
}
static void log_reopen_if_forced(void) {
if (!debug_enabled || !g_log_forced || !g_log_forced_path[0]) return;
FILE *old = g_log;
g_log = NULL;
if (old) fclose(old);
int fd = open(g_log_forced_path, O_CREAT|O_APPEND|O_WRONLY, 0640);
if (fd < 0) { g_log = old; return; }
FILE *nf = fdopen(fd, "a");
if (!nf) { close(fd); g_log = old; return; }
g_log = nf; snprintf(g_log_path, sizeof(g_log_path), "%s", g_log_forced_path);
}
/* open an explicit path for logging (used by forced global log mode) */
static void log_open_path(const char *path) {
if (!debug_enabled || g_log || !path || !*path) return;
@@ -163,6 +179,12 @@ static void install_signal_handlers(void) {
sigaction(SIGINT, &ign, NULL); /* ^C */
sigaction(SIGTSTP, &ign, NULL); /* ^Z */
sigaction(SIGQUIT, &ign, NULL); /* ^\ */
/* SIGUSR1 from logrotate -> reopen forced log file */
struct sigaction hup;
memset(&hup, 0, sizeof(hup));
hup.sa_handler = (void (*)(int))log_reopen_if_forced;
sigaction(SIGUSR1, &hup, NULL);
}
/* ---------- helpers ---------- */
@@ -368,11 +390,41 @@ static void stop_greeter_keeper(void) {
}
}
/* ---------- CLI helpers ---------- */
static void print_version(void) {
/* FBLOGIN_VERSION comes from version.h */
printf("fblogin %s\n", FBLOGIN_VERSION);
}
static void print_help(const char *argv0) {
const char *prog = argv0 ? argv0 : "fblogin";
printf(
"Usage: %s [options]\n"
"\n"
"Options:\n"
" -h, --help Show this help and exit\n"
" -V, --version Show version and exit\n"
" -d, --debug Enable debug logging (can also set FBLOGIN_DEBUG=1)\n"
" --dev Developer mode (relaxes some context checks)\n"
" --no-fp Disable fingerprint path\n"
" --fp-max=N Cosmetic max retries shown for fingerprint (1..9)\n"
" --log-file=PATH Force all logs to PATH (implies --debug)\n"
"\n"
"Environment:\n"
" FBLOGIN_DEBUG=1 enable debug logs\n"
" FBLOGIN_LOG_FILE=/path force global log file (pair with DEBUG=1)\n"
" FBLOGIN_FINGERPRINT=0 disable fingerprint\n"
" FBLOGIN_DEV=1 enable developer mode\n"
" FBLOGIN_CMATRIX=1 enable cmatrix background\n"
"\n", prog);
}
/* ---------- main ---------- */
int main(int argc, char **argv) {
int dev_mode = 0;
int fp_enabled = FBLOGIN_WITH_FPRINTD;
int fp_max = 3; /* cosmetic; PAM module controls real retries */
int show_help = 0, show_version = 0;
/* allow --log-file=/path to also imply debug on */
/* (systemd env FBLOGIN_DEBUG=1 still supported/used below) */
@@ -395,7 +447,16 @@ int main(int argc, char **argv) {
debug_enabled = 1; /* make --log-file alone sufficient */
}
}
else if (!strcmp(argv[i], "--help") || !strcmp(argv[i], "-h")) {
show_help = 1;
}
else if (!strcmp(argv[i], "--version") || !strcmp(argv[i], "-V")) {
show_version = 1;
}
}
if (show_help) { print_help(argv[0]); return 0; }
if (show_version) { print_version(); return 0; }
if (!debug_enabled) {
const char *env = getenv("FBLOGIN_DEBUG");
if (env && *env == '1') debug_enabled = 1;