armybox 0.3.0

A memory-safe #[no_std] BusyBox/Toybox clone in Rust - 299 Unix utilities in ~500KB
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218

//! ping - send ICMP ECHO_REQUEST to network hosts
//!
//! Send ICMP ECHO_REQUEST packets to network hosts.

use crate::io;
use crate::sys;
use super::get_arg;

/// ping - send ICMP ECHO_REQUEST to network hosts
///
/// # Synopsis
/// ```text
/// ping [-c count] HOST
/// ```
///
/// # Description
/// Send ICMP ECHO_REQUEST packets to a network host and report responses.
///
/// # Options
/// - `-c count`: Stop after sending count packets
///
/// # Exit Status
/// - 0: At least one response received
/// - 1: No response received or error
pub fn ping(argc: i32, argv: *const *const u8) -> i32 {
    if argc < 2 {
        io::write_str(2, b"ping: missing host\n");
        return 1;
    }

    let host = unsafe { get_arg(argv, argc - 1).unwrap() };
    let mut count = 4i32;

    // Parse -c option
    for i in 1..argc-1 {
        if let Some(arg) = unsafe { get_arg(argv, i) } {
            if arg == b"-c" && i + 1 < argc - 1 {
                if let Some(c) = unsafe { get_arg(argv, i + 1) } {
                    count = sys::parse_i64(c).unwrap_or(4) as i32;
                }
            }
        }
    }

    io::write_str(1, b"PING ");
    io::write_all(1, host);
    io::write_str(1, b" 56 data bytes\n");

    // Create raw socket for ICMP
    let sock = unsafe { libc::socket(libc::AF_INET, libc::SOCK_RAW, libc::IPPROTO_ICMP) };
    if sock < 0 {
        io::write_str(2, b"ping: socket: Operation not permitted\n");
        return 1;
    }

    // Resolve hostname
    let mut host_buf = [0u8; 256];
    host_buf[..host.len()].copy_from_slice(host);

    let mut hints: libc::addrinfo = unsafe { core::mem::zeroed() };
    hints.ai_family = libc::AF_INET;
    let mut res: *mut libc::addrinfo = core::ptr::null_mut();

    if unsafe { libc::getaddrinfo(host_buf.as_ptr() as *const i8, core::ptr::null(), &hints, &mut res) } != 0 {
        io::write_str(2, b"ping: unknown host\n");
        unsafe { libc::close(sock) };
        return 1;
    }

    let addr = unsafe { *((*res).ai_addr as *const libc::sockaddr_in) };
    unsafe { libc::freeaddrinfo(res) };

    let mut sent = 0;
    let mut received = 0;

    for seq in 0..count {
        // Build ICMP echo request
        let mut packet = [0u8; 64];
        packet[0] = 8; // ICMP Echo Request
        packet[1] = 0; // Code
        // Checksum at 2-3, will compute
        packet[4] = 0; packet[5] = 1; // ID
        packet[6] = (seq >> 8) as u8; packet[7] = seq as u8; // Sequence

        // Compute checksum
        let mut sum: u32 = 0;
        for i in (0..64).step_by(2) {
            sum += ((packet[i] as u32) << 8) | (packet[i+1] as u32);
        }
        while sum >> 16 != 0 {
            sum = (sum & 0xffff) + (sum >> 16);
        }
        let checksum = !sum as u16;
        packet[2] = (checksum >> 8) as u8;
        packet[3] = checksum as u8;

        let start = unsafe { libc::time(core::ptr::null_mut()) };

        let sent_bytes = unsafe {
            libc::sendto(
                sock,
                packet.as_ptr() as *const libc::c_void,
                64,
                0,
                &addr as *const _ as *const libc::sockaddr,
                core::mem::size_of::<libc::sockaddr_in>() as u32,
            )
        };

        if sent_bytes > 0 {
            sent += 1;

            // Set receive timeout
            let tv = libc::timeval { tv_sec: 1, tv_usec: 0 };
            unsafe { libc::setsockopt(sock, libc::SOL_SOCKET, libc::SO_RCVTIMEO, &tv as *const _ as *const libc::c_void, core::mem::size_of::<libc::timeval>() as u32) };

            let mut recv_buf = [0u8; 128];
            let mut from: libc::sockaddr_in = unsafe { core::mem::zeroed() };
            let mut fromlen = core::mem::size_of::<libc::sockaddr_in>() as u32;

            let recv_bytes = unsafe {
                libc::recvfrom(
                    sock,
                    recv_buf.as_mut_ptr() as *mut libc::c_void,
                    recv_buf.len(),
                    0,
                    &mut from as *mut _ as *mut libc::sockaddr,
                    &mut fromlen,
                )
            };

            let end = unsafe { libc::time(core::ptr::null_mut()) };
            let rtt = (end - start) * 1000; // Approximate ms

            if recv_bytes > 0 {
                received += 1;
                io::write_str(1, b"64 bytes from ");
                io::write_all(1, host);
                io::write_str(1, b": icmp_seq=");
                let mut num_buf = [0u8; 20];
                io::write_all(1, sys::format_u64((seq + 1) as u64, &mut num_buf));
                io::write_str(1, b" time=");
                io::write_all(1, sys::format_u64(rtt as u64, &mut num_buf));
                io::write_str(1, b" ms\n");
            }
        }

        if seq < count - 1 {
            unsafe { libc::sleep(1) };
        }
    }

    unsafe { libc::close(sock) };

    // Print statistics
    io::write_str(1, b"\n--- ");
    io::write_all(1, host);
    io::write_str(1, b" ping statistics ---\n");
    let mut num_buf = [0u8; 20];
    io::write_all(1, sys::format_u64(sent as u64, &mut num_buf));
    io::write_str(1, b" packets transmitted, ");
    io::write_all(1, sys::format_u64(received as u64, &mut num_buf));
    io::write_str(1, b" received, ");
    let loss = if sent > 0 { ((sent - received) * 100 / sent) as u64 } else { 100 };
    io::write_all(1, sys::format_u64(loss, &mut num_buf));
    io::write_str(1, b"% packet loss\n");

    if received > 0 { 0 } else { 1 }
}

#[cfg(test)]
mod tests {
    extern crate std;
    use std::process::Command;
    use std::path::PathBuf;

    fn get_armybox_path() -> PathBuf {
        if let Ok(path) = std::env::var("ARMYBOX_PATH") {
            return PathBuf::from(path);
        }
        let manifest_dir = std::env::var("CARGO_MANIFEST_DIR")
            .map(PathBuf::from)
            .unwrap_or_else(|_| std::env::current_dir().unwrap());
        let release = manifest_dir.join("target/release/armybox");
        if release.exists() { return release; }
        manifest_dir.join("target/debug/armybox")
    }

    #[test]
    fn test_ping_no_args() {
        let armybox = get_armybox_path();
        if !armybox.exists() { return; }

        let output = Command::new(&armybox)
            .args(["ping"])
            .output()
            .unwrap();

        assert_eq!(output.status.code(), Some(1));
        let stderr = std::string::String::from_utf8_lossy(&output.stderr);
        assert!(stderr.contains("missing host"));
    }

    #[test]
    fn test_ping_requires_root() {
        let armybox = get_armybox_path();
        if !armybox.exists() { return; }

        // Without root, should fail with permission error
        let output = Command::new(&armybox)
            .args(["ping", "-c", "1", "127.0.0.1"])
            .output()
            .unwrap();

        // Either succeeds (as root) or fails with permission denied
        assert!(output.status.code() == Some(0) || output.status.code() == Some(1));
    }
}