What is the ruling on a man fondling his own chest with the intention of alleviating lust, without ejaculation, by analogy with the permissibility of a woman fondling her own chest during intercourse?

The legitimate way to satisfy lust is by enjoying one's wife or female slave (malak al-yamin). Anything other than that is an impermissible transgression. A man's enjoyment through caressing his chest is not permissible; it is a deviation and an anomaly. The legitimate way for someone who cannot marry to overcome lust is by fasting, while guarding one's hearing and sight, staying away from places of temptation, and occupying one's time with beneficial deeds, all while seeking help from Allah and holding fast to Him.