Add utility for setting configuration for a context

3 files changed, 198 insertions, 45 deletions

diff --git a/embassy-net-nrf91/src/at.rs b/embassy-net-nrf91/src/at.rs
deleted file mode 100644
index 04cbf3876..000000000
--- a/embassy-net-nrf91/src/at.rs
+++ /dev/null
@@ -1,45 +0,0 @@
-use crate::{Error, Control};
-
-// Drives the control loop of the modem based on declarative configuration.
-pub struct AtDriver<'a> {
-    control: Control<'a>,
-    config: Config,
-}
-
-pub struct Config {
-    pub network: NetworkConfig,
-}
-
-pub struct NetworkConfig {
-    pub apn: &'static str,
-    pub prot: AuthProtection,
-    pub userid: &'static str,
-    pub password: &'static str,
-}
-
-#[repr(u8)]
-pub enum AuthProtection {
-    None = 0,
-    Pap = 1,
-    Chap = 2,
-}
-
-impl<'a> AtDriver<'a> {
-    pub async fn new(control: Control<'a>, config: Config) -> Result<Self, Error> {
-        control.wait_init().await;
-        Ok(Self {
-            control,
-            config,
-        })
-    }
-
-    async fn setup(&self) -> Result<(), Error> {
-
-    }
-
-    pub fn run(&self, stack: Stack<crate::NetDriver<'static>>) -> ! {
-        loop {
-
-        }
-    }
-}
diff --git a/embassy-net-nrf91/src/context.rs b/embassy-net-nrf91/src/context.rs
new file mode 100644
index 000000000..6dda51793
--- /dev/null
+++ b/embassy-net-nrf91/src/context.rs
@@ -0,0 +1,196 @@
+use core::net::IpAddr;
+use heapless::String;
+use core::str::FromStr;
+use core::fmt::Write;
+
+/// Provides a higher level API for configuring and reading information for a given
+/// context id.
+pub struct Control<'a> {
+    control: crate::Control<'a>,
+    cid: u8,
+}
+
+pub struct Config<'a> {
+    pub gateway: &'a str,
+    pub auth_prot: AuthProt,
+    pub auth: Option<(&'a str, &'a str)>,
+}
+
+#[repr(u8)]
+pub enum AuthProt {
+    None = 0,
+    Pap = 1,
+    Chap = 2,
+}
+
+#[derive(Clone, Copy, PartialEq, Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum Error {
+    BufferTooSmall,
+    AtCommand,
+    AddrParseError,
+    Format,
+}
+
+impl From<core::fmt::Error> for Error {
+    fn from(_: core::fmt::Error) -> Self {
+        Self::Format
+    }
+}
+
+#[derive(PartialEq, Debug)]
+pub struct Status {
+    pub attached: bool,
+    pub ip: Option<IpAddr>,
+}
+
+#[cfg(feature = "defmt")]
+impl defmt::Format for Status {
+    fn format(&self, f: defmt::Formatter<'_>) {
+        defmt::write!(f, "attached: {}", self.attached);
+        if let Some(ip) = &self.ip {
+            defmt::write!(f, ", ip: {}", defmt::Debug2Format(&ip));
+        }
+    }
+}
+
+impl<'a> Control<'a> {
+    pub async fn new(control: crate::Control<'a>, cid: u8) -> Self {
+        control.wait_init().await;
+        Self { control, cid }
+    }
+
+    /// Bypass modem configurator
+    pub async fn at_command(&self, req: &[u8], resp: &mut [u8]) -> usize {
+        self.control.at_command(req, resp).await
+    }
+
+    /// Configures the modem with the provided config.
+    pub async fn configure(&self, config: Config<'_>) -> Result<(), Error> {
+        let mut cmd: String<128> = String::new();
+        let mut buf: [u8; 256] = [0; 256];
+
+        write!(cmd, "AT+CGDCONT={},\"IP\",\"{}\"", self.cid, config.gateway).map_err(|_| Error::BufferTooSmall)?;
+        let n = self.control.at_command(cmd.as_bytes(), &mut buf).await;
+        let mut res = &buf[..n];
+        let res = split_field(&mut res);
+        if res != b"OK" {
+            return Err(Error::AtCommand)
+        }
+        cmd.clear();
+
+        write!(cmd, "AT+CGAUTH={},{}", self.cid, config.auth_prot as u8)?;
+        if let Some((username, password)) = config.auth {
+            write!(cmd, ",\"{}\",\"{}\"", username, password).map_err(|_| Error::BufferTooSmall)?;
+        }
+        let n = self.control.at_command(cmd.as_bytes(), &mut buf).await;
+        let mut res = &buf[..n];
+        let res = split_field(&mut res);
+        if res != b"OK" {
+            return Err(Error::AtCommand)
+        }
+        cmd.clear();
+
+        let n = self.control.at_command(b"AT+CFUN=1", &mut buf).await;
+        let mut res = &buf[..n];
+        let res = split_field(&mut res);
+        if res != b"OK" {
+            return Err(Error::AtCommand);
+        }
+
+        Ok(())
+    }
+
+    pub async fn status(&self) -> Result<Status, Error> {
+        let mut buf: [u8; 256] = [0; 256];
+        let n = self.control.at_command(b"AT+CGATT?", &mut buf).await;
+        let mut res = &buf[..n];
+        pop_prefix(&mut res, b"+CGATT: ");
+        let res = split_field(&mut res);
+        let attached = res == b"1";
+
+        if !attached {
+            return Ok(Status { attached, ip: None })
+        }
+
+        let mut s: String<128> = String::new();
+        write!(s, "AT+CGPADDR={}", self.cid)?;
+        let n = self.control.at_command(s.as_bytes(), &mut buf).await;
+        let mut res = &buf[..n];
+        s.clear();
+
+        write!(s, "+CGPADDR: {},", self.cid)?;
+
+        info!("RES: {:?}", unsafe {core::str::from_utf8_unchecked(res)});
+        if s.len() > res.len() {
+            let res = split_field(&mut res);
+            if res == b"OK" {
+                Ok(Status { attached, ip: None })
+            } else {
+                Err(Error::AtCommand)
+            }
+        } else {
+            pop_prefix(&mut res, s.as_bytes());
+
+            let ip = split_field(&mut res);
+            if !ip.is_empty() {
+                let ip = IpAddr::from_str(unsafe { core::str::from_utf8_unchecked(ip) }).map_err(|_| Error::AddrParseError)?;
+                self.control.open_raw_socket().await;
+                Ok(Status { attached, ip: Some(ip) })
+            } else {
+                Ok(Status { attached, ip: None })
+            }
+        }
+    }
+}
+
+pub(crate) fn is_whitespace(char: u8) -> bool {
+    match char {
+        b'\r' | b'\n' | b' ' => true,
+        _ => false,
+    }
+}
+
+pub(crate) fn is_separator(char: u8) -> bool {
+    match char {
+        b',' | b'\r' | b'\n' | b' ' => true,
+        _ => false,
+    }
+}
+
+pub(crate) fn split_field<'a>(data: &mut &'a [u8]) -> &'a [u8] {
+    while !data.is_empty() && is_whitespace(data[0]) {
+        *data = &data[1..];
+    }
+
+    if data.is_empty() {
+        return &[];
+    }
+
+    if data[0] == b'"' {
+        let data2 = &data[1..];
+        let end = data2.iter().position(|&x| x == b'"').unwrap_or(data2.len());
+        let field = &data2[..end];
+        let mut rest = &data2[data2.len().min(end + 1)..];
+        if rest.first() == Some(&b'\"') {
+            rest = &rest[1..];
+        }
+        while !rest.is_empty() && is_separator(rest[0]) {
+            rest = &rest[1..];
+        }
+        *data = rest;
+        field
+    } else {
+        let end = data.iter().position(|&x| is_separator(x)).unwrap_or(data.len());
+        let field = &data[0..end];
+        let rest = &data[data.len().min(end + 1)..];
+        *data = rest;
+        field
+    }
+}
+
+pub(crate) fn pop_prefix(data: &mut &[u8], prefix: &[u8]) {
+    assert!(data.len() >= prefix.len());
+    assert!(&data[..prefix.len()] == prefix);
+    *data = &data[prefix.len()..];
+}
diff --git a/embassy-net-nrf91/src/lib.rs b/embassy-net-nrf91/src/lib.rs
index 70ad176da..beed7c65a 100644
--- a/embassy-net-nrf91/src/lib.rs
+++ b/embassy-net-nrf91/src/lib.rs
@@ -6,6 +6,8 @@
 // must be first
 mod fmt;
 
+pub mod context;
+
 use core::cell::RefCell;
 use core::future::poll_fn;
 use core::marker::PhantomData;