Automate nmap scanning for multiple domains with threads

scan_hosts.sh

#!/bin/bash

# Author: Gustavo Lichti
# Email: gustavo.lichti@gmail.com

# Usage: ./scan_hosts.sh --hosts <hosts_file> --host xpto.xxx --host xpto2.xxx --threads <number_of_threads> --output <output_directory>

SCRIPT_STARTED=$(date +"%Y%m%d_%H%M")

# Function do add log Line
log_this() {
    # USAGE log_this <LOG_FILE> <TAG> <LOG_LINE>
    # USAGE log_this ${LOG_FILE} <TAG> <LOG_LINE>

    NOW=$(date +"%Y%m%d_%H:%M:%S")
    LOG_FILE=$1; shift
    TAG=$1; shift
    LOG_LINE=$@

    echo "[${NOW}] [${TAG}] ${LOG_LINE}" | tee -a ${LOG_FILE}  

}

# Define the function to run nmap scan for unique IPs
run_nmap() {
    IP="$1"
    SCAN_STARTED=$(date +"%Y%m%d_%H%M")
    log_this ${LOG_FILE} NMAP "Scanning IP: ${IP} at ${SCAN_STARTED}..."
    
    nmap -Pn -sV -sS "${IP}" -oN "$OUTPUT_DIR/nmap_report_${IP}_${SCAN_STARTED}.txt"
    
    SCAN_ENDED=$(date +"%Y%m%d_%H%M")
    log_this ${LOG_FILE} NMAP "Scan completed for IP: ${IP} at ${SCAN_ENDED}"
}

# Function to process host(s)
process_hosts() {
    while read -r host; do
        ips=$(dig +short "$host" | grep -E '([0-9]{1,3}\.){3}[0-9]{1,3}')
        while read -r ip; do
            echo "$host:$ip" >> "$OUTPUT_DIR/host_ip.txt"
            echo "${ip}"
        done <<< "$ips"
    done | sort -u > "$OUTPUT_DIR/uniq_ips.txt"

    log_this ${LOG_FILE} PROCESS "Domain to IP mapping completed."


    # Run nmap in parallel with a limit of 10 processes for unique IPs
    xargs -n 1 -P  "${THREADS}" -a "$OUTPUT_DIR/uniq_ips.txt" -I{} bash -c 'run_nmap "$@"' _ {}

    log_this ${LOG_FILE} PROCESS "IP scan completed."
}

# Check for provided hosts file or hosts
while [[ $# -gt 0 ]]; do
    key="$1"

    case $key in
        --hosts)
            HOSTS_FILE="$2"
            shift # past argument
            shift # past value
            ;;
        --host)
            HOSTS+=("$2")
            shift # past argument
            shift # past value
            ;;
        --threads)
            THREADS="$2"
            shift # past argument
            shift # past value
            ;;
        --output)
            OUTPUT_DIR ="$2"
            shift # past argument
            shift # past value
            ;;
        *) # unknown option
            echo "Ignoring unknown option: $key"
            shift # past argument
            ;;
    esac
done

# Set default values if not provided
THREADS="${THREADS:-10}"
OUTPUT_DIR="${OUTPUT_DIR:-$(dirname "$HOSTS_FILE")/output_${SCRIPT_STARTED}}"
LOG_FILE="$OUTPUT_DIR/log_${SCRIPT_STARTED}_$ip.txt"

# Exports to make it available to xargs
export -f run_nmap
export -f log_this
export LOG_FILE
export OUTPUT_DIR

# Create output directory and log file
mkdir -p "$OUTPUT_DIR"
touch ${LOG_FILE}

# Check if either hosts file or individual hosts are provided
if [ -z "$HOSTS_FILE" ] && [ ${#HOSTS[@]} -eq 0 ]; then
    log_this ${LOG_FILE} INIT "Please provide a hosts file using --hosts or individual hosts using --host."
    exit 1
fi

# Process individual hosts if provided
if [ ${#HOSTS[@]} -gt 0 ]; then
    log_this ${LOG_FILE} HOST "Processing individual hosts:"
    # Create a temporary hosts file
    TMP_HOSTS_FILE="tmp_hosts_${SCRIPT_STARTED}"
    for host in "${HOSTS[@]}"; do
        log_this ${LOG_FILE} HOST "$host"
    done > "$TMP_HOSTS_FILE"
    if [ -n "$HOSTS_FILE" ]; then
	log_this ${LOG_FILE} HOSTPARAM "Append extra hosts to HOSTS_FILE"
        cat "$TMP_HOSTS_FILE" >> "$HOSTS_FILE"
    else
	log_this ${LOG_FILE} HOST "Setting TMP_HOSTS_FILE as HOSTS_FILE"
        HOSTS_FILE="$TMP_HOSTS_FILE"
    fi
fi

# Check if hosts file exists and process it
if [ -n "$HOSTS_FILE" ]; then
    if [ ! -f "$HOSTS_FILE" ]; then
        log_this ${LOG_FILE} HOSTSP "Hosts file ${HOSTS_FILE} not found"
        exit 1
    fi
    log_this ${LOG_FILE} HOSTS "Processing hosts from file: ${HOSTS_FILE}"
    process_hosts < "${HOSTS_FILE}"
fi