ROM with ROM 2.4
ROM 2.4 remains a foundational DikuMUD derivative widely used for hobby MUDs. This guide addresses the specific friction points of compiling 1990s C code on modern x86_64 systems, patching inherited Merc vulnerabilities, and configuring directory structures for persistent hosting. Assumes Ubuntu 22.04 LTS or equivalent Debian-based server environment.
Install 32-bit Compatibility Libraries
ROM 2.4 assumes 32-bit memory alignment in several Merc-derived pointer operations. On x86_64 systems, install multilib support to prevent segmentation faults during player file loading.
sudo apt-get update && sudo apt-get install gcc-multilib libc6-dev-i386 build-essential⚠ Common Pitfalls
- •Do not skip this on 64-bit systems or expect immediate crashes on player login
Patch Buffer Overflow Vulnerabilities
Stock ROM uses unbounded sprintf in save.c and act_comm.c. Replace with snprintf and define NAME_LEN limits to prevent crashes from long player names or object descriptions.
// In save.c, replace:
// sprintf( strsave, "%s%s", PLAYER_DIR, ch->name );
// With:
snprintf( strsave, sizeof(strsave), "%s%s", PLAYER_DIR, ch->name );⚠ Common Pitfalls
- •Check all sprintf instances; there are 12 in stock ROM
- •Verify PLAYER_DIR ends with trailing slash
Configure Absolute Directory Paths
Stock ROM uses relative paths in merc.h that fail when the binary executes from cron or systemd services. Define AREA_LIST, PLAYER_DIR, and GOD_DIR as absolute paths pointing to your installation.
#define AREA_LIST "/var/mud/rom/area/area.lst"
#define PLAYER_DIR "/var/mud/rom/player/"
#define GOD_DIR "/var/mud/rom/gods/"Adjust Hardcoded Memory Limits
Increase MAX_STRING_LENGTH from 4096 to 8192 and MAX_SKILL from 150 to 300. These 1993-era defaults truncate modern area files and limit class customization options.
#define MAX_STRING_LENGTH 8192
#define MAX_SKILL 300
#define MAX_CLASS 10⚠ Common Pitfalls
- •Increasing MAX_STRING_LENGTH affects mob_index_data size; monitor RAM usage
- •MAX_SKILL requires corresponding skill table updates
Modify Makefile for Modern GCC
Add -fno-strict-aliasing to CFLAGS to prevent crashes from Merc's union-based type punning between OBJ_DATA and OBJ_INDEX_DATA. Remove -O3 optimization that breaks legacy pointer arithmetic.
CFLAGS = -g -O2 -Wall -Wextra -fno-strict-aliasing -DNOCRYPT
CC = gcc
LIBS = -lcrypt⚠ Common Pitfalls
- •-fstrict-aliasing is default in GCC 4.0+ and causes intermittent crashes
- •Do not use -O3; it optimizes out critical delay loops
Resolve Area File Vnum Collisions
Stock ROM areas contain overlapping virtual numbers. Before booting, scan area files for duplicate vnums between limbo.are and other stock zones that cause fatal boot errors.
grep -h '^#\([0-9]*\)' area/*.are | sort | uniq -d⚠ Common Pitfalls
- •Duplicate vnums cause immediate SIGSEGV during area loading
- •Backup area files before editing vnum ranges
Debug Initial Boot Sequence
Execute the binary under GDB to catch segmentation faults during area parsing. Set breakpoints in boot_db and load_rooms to identify malformed area files before daemonizing.
gdb ./rom
(gdb) set pagination off
(gdb) run 4000
# When crash occurs:
(gdb) bt full⚠ Common Pitfalls
- •Never run as root; create mud user first
- •Ensure area.lst paths match actual .are filenames exactly
Configure Network Binding
Verify the MUD binds to 0.0.0.0 rather than 127.0.0.1 for external MUSHclient access. Check with netstat and configure UFW firewall rules for port 4000 or your chosen port.
sudo netstat -tlnp | grep rom
sudo ufw allow 4000/tcpWhat you built
ROM 2.4 is now operational with modern security patches and memory limits. Next steps include customizing class tables in const.c, removing stock areas from area.lst, and implementing hotboot copyover support. Monitor syslog for crypt() deprecation warnings on newer glibc versions.
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