I assume that by 'cannabis' you mean hemp, or rather Cannabis sativa var. indica of the family Moraceae.
From where it came? We can't be really sure, but the cannabis has been widely known in India and China in 3rd millenium BC (oldest Chinese source mentioning hemp fibres is dated 27th century BC and linked to mythical figure of Shen Nung)[1]. It is suggested that cannabis has been known around 12 000 BCE in the Tarim Basin (uyg. Altyshahr, modern Xinjiang province in China) [2]. Around 2000 BC they were already cultivated in Korean peninsula and Middle East (modern Iran/Afghanistan) and in the next centuries it was used in the Don Basin and near the shores of the Azov Sea (modern Southeastern Ukraine)[3]. From there, hemp made its way to Central Europe in pre-Slavic times, roughly around 10th century BC [4] and then was adopted in modern Germany and France between 4th and 5th century by migrating Gothic tribes and then it made its way to British Isles during Anglo-Saxon invasion.[5]
Herodotus, in his work 'On the Scythians' mentions the use of hemp by Pontic and Balkan tribes and Scythians suggesting that it was commonplace among Scythians, was used by Thracians but was most likely unknown in Hellenic world, to wit:
'74. Hemp grows in Scythia: it is very like flax; only that it is a much coarser and taller plant: some grows wild about the country, some is produced by cultivation: the Thracians make garments of it which closely resemble linen;'
'75. The Scythians, as I said, take some of this hempseed, and, creeping under the felt coverings, throw it upon the red-hot stones; immediately it smokes,and gives out such a vapour as no Grecian vapour-bath can exceed; the Scyths, delighted, shout for joy, and this vapour serves them instead of a waterbath.'[6]
This allows us to assume that cannabis came to Europe from Central Asia through the Eurasian steppes and was known in southeastern Europe in 5th century BC. Etymological analysis may suggest that the cannabis came to Europe through or from India, as most European names show the similarity to Sanskrit work 'khanap', rather than Chinese 'ma2'(a) (far. 'kanap', rus. 'konoplya', pol. 'konopie', ger. 'hanf', OE 'haenep', eng. 'hemp', spa. 'canamo', fre. 'chanvre').
It is highly probable that the cannabis was not used for smoking, as the idea of smoking plants was not that popular before adoption of tobacco. Leaves were commonly used for making infusions but the most common medical products were fibers (for clothing, sacks, ropes, sails etc.), oil (for both technical and medicinal purposes) and seeds (for consumption, along with lineseed).
And then we have this gem from Symon Syrenius, included in his herbary detailing the shape, location, use and effects of various plants. The following fragment is included in the description of hemp (most likely cannabis sativa, as he separately describes 'wild (sylvan) hemp', most likely cannabis ruderalis):
Turkish maslok(b): Dust of dry hemp leaves, ground throoughly and mixed with any drink causes inebriation, but by itself it does not cause inebriation. Therefore, Turks and their Janissaries use hemp flowers to make various masloks: some for the levity of heart and mind, others for sorrow and tears, others for love of Venus and others for courage and joviality, for combat and fight. As its vapor permeates the brain in strong yet subtle manner, one Who takes the hemp flower, adopts queer humours or has his vapours stirred by heat so that one does not know what one does as he is left without a shred or reason and awareness. [...] Hemp oil, when used in excess, cause heaviness of the the head.
The reaction of the authorities back then was, shortly speaking, non-existent. There are few indications that hemp has been massively used for recreational intoxication (it is highly possible that European cultivars have had low cannabinols content and were not suited for such use) and the legislation until late 19th century was not prohibiting use of cultivation of any toxic or narcotic plants. Opposition against recreational drugs in Europe (well, alcohol, mostly) was almost solely a domain of temperance movements, often of religious origin. Muslim world is another story, as a question whether Qur'an prohibits only drinking alcohol or using any mind-altering substances was discussed at length by Muslim religious authorities. As the question asked here does not refer to North Africa and Middle East, I will only recommend Rosenthal's 'Man versus Society in Medieval Islam', where he addresses the problem in detail.[8]
If anything, hemp cultivation was encouraged rather than hampered. Due to increased demand for hemp to make ropes and sails for the quickly developing navy, Henry VIII decreed in 1533 that each and every farmer holding more than 60 acres of land must grow at least one rood (a quarter of an acre) of hemp under an penalty of fine. In 1563, Queen Elisabeth increased the requirement to at least one acre. In 1611, James I demanded hemp cultivation in American colonies to alleviate dependency on foreign markets (in 1630, England imported 90% of its hemp from Russia and Polish-Lithuanian Commonwealth).[9]
a.) Number 2 after a name indicates the rising tone.
b.) Maslok (also maslek, maslah) - herbal extract, usually associated with intoxicating or analgesic effect. In 16th century Poland, adjective 'masłokowy' was a rough equivalent to modern adjective 'narcotic' or 'intoxicating'.
[1] Anthony Christie, Chinese Mythology. London 1997.
[2] Ernest Abel, Marihuana: The First Twelve Thousand Years. New York, 1980.
[3] P.S. Chikov, Y.P. Laptyev, Bитаминные и лекарственное растения (Nutritional and medicinal plants), Kolos, 1987.
[4] Iwona Arabas, Z historii używana konopi w Polsce (History of hemp usage in Poland), Warsaw, 1990.
[5] Barney Warf, High Points. An Historical Geography of Cannabis in: Geographical Review, vol. 104, issue 4, October 2014.
[6] Herodotus, On the Scythians (The Persian Wars, Book IV) in: F.R. Godolphin (ed.) The Greek Historians, Random House, 1970.
[7] Symon Syreniusz Zielnik herbarzem z języka łacińskiego zowią[...] (Herbary, or herbarius as known in Latin language [...]), Book III, Krakow, 1613. Personal translation.
[8] Franz Rosenthal, Man versus Society in Medieval Islam, Leiden, 2015. (especially chapter III 'The Herb: Hashish versus Medieval Muslim Society' and Sub-chapter VI.1 'Cannabis and Alcohol: The Green and Red'.
[9] Henryk Zins, England and the Baltic in the Elizabethan era. (transl. by H.C. Stevens) Manchester, 1972.