Function build_response_with_headers

src/sip/parser.rs:153–210

从 SIP 请求构建带有额外头部的响应

(
    request: &str,
    status_code: u16,
    reason: &str,
    extra_headers: &[(&str, &str)],
)

/// 从 SIP 请求构建带有额外头部的响应
pub fn build_response_with_headers(
    request: &str,
    status_code: u16,
    reason: &str,
    extra_headers: &[(&str, &str)],
) -> Vec<u8> {
    let mut via_headers = Vec::new();
    let mut from_header = String::new();
    let mut to_header = String::new();
    let mut call_id_header = String::new();
    let mut cseq_header = String::new();

    for line in request.lines() {
        let line_trimmed = line.trim();
        if line_trimmed.is_empty() {
            break;
        }
        let lower = line_trimmed.to_lowercase();
        if lower.starts_with("via:") || lower.starts_with("v:") {
            via_headers.push(line_trimmed.to_string());
        } else if lower.starts_with("from:") || lower.starts_with("f:") {
            from_header = line_trimmed.to_string();
        } else if lower.starts_with("to:") || lower.starts_with("t:") {
            to_header = line_trimmed.to_string();
        } else if lower.starts_with("call-id:") || lower.starts_with("i:") {
            call_id_header = line_trimmed.to_string();
        } else if lower.starts_with("cseq:") {
            cseq_header = line_trimmed.to_string();
        }
    }

    if status_code > 100 && !to_header.to_lowercase().contains("tag=") {
        to_header = format!("{};tag={}", to_header, generate_tag());
    }

    let mut response = format!("SIP/2.0 {} {}\r\n", status_code, reason);
    for via in &via_headers {
        response.push_str(via);
        response.push_str("\r\n");
    }
    response.push_str(&from_header);
    response.push_str("\r\n");
    response.push_str(&to_header);
    response.push_str("\r\n");
    response.push_str(&call_id_header);
    response.push_str("\r\n");
    response.push_str(&cseq_header);
    response.push_str("\r\n");

    for (name, value) in extra_headers {
        response.push_str(&format!("{}: {}\r\n", name, value));
    }

    response.push_str("Content-Length: 0\r\n");
    response.push_str("\r\n");

    response.into_bytes()
}