(19)
(11)EP 3 490 226 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
07.10.2020 Bulletin 2020/41

(21)Application number: 18208127.3

(22)Date of filing:  23.11.2018
(51)International Patent Classification (IPC): 
H04L 29/08(2006.01)
H04W 12/06(2009.01)
H04L 29/06(2006.01)
H04W 84/12(2009.01)
H04L 29/12(2006.01)
H04W 12/00(2009.01)
H04W 12/08(2009.01)

(54)

CAPTIVE PORTAL DETECTION

CAPTIVE PORTAL ERKENNUNG

DÉTECTION DE PORTAIL CAPTIF


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 23.11.2017 IN 201741042061

(43)Date of publication of application:
29.05.2019 Bulletin 2019/22

(73)Proprietor: Harman International Industries, Incorporated
Stamford, CT 06901 (US)

(72)Inventor:
  • Shanbhag, Sandeep
    560102 Bangalore (IN)

(74)Representative: Rummler, Felix 
Maucher Jenkins Liebigstrasse 39
80538 München
80538 München (DE)


(56)References cited: : 
US-A1- 2015 295 885
US-A1- 2017 111 269
  
  • TEEMU KÄRKKÄINEN ET AL: "Enabling ad-hoc-style communication in public WLAN hot-spots", CHALLENGED NETWORKS, ACM, 2 PENN PLAZA, SUITE 701 NEW YORK NY 10121-0701 USA, 22 August 2012 (2012-08-22), pages 31-38, XP058009256, DOI: 10.1145/2348616.2348623 ISBN: 978-1-4503-1284-4
  • DONNELLY M CULLEN PAINLESS SECURITY M: "Captive Portal Detection and Interaction; draft-donnelly-capport-detection-00.txt", CAPTIVE PORTAL DETECTION AND INTERACTION; DRAFT-DONNELLY-CAPPORT-DETECTION-00.TXT; INTERNET-DRAFT: CAPTIVE PORTAL WG, INTERNET ENGINEERING TASK FORCE, IETF; STANDARDWORKINGDRAFT, INTERNET SOCIETY (ISOC) 4, RUE DES FALAISES CH- 1205 GENEVA, SWITZERLAN, 14 March 2017 (2017-03-14), pages 1-13, XP015124564, [retrieved on 2017-03-14]
  
Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


Description

TECHNICAL FIELD



[0001] The present disclosure is directed to a method for captive portal detection.

BACKGROUND



[0002] Captive portals are used by venues that provide free Wi-Fi hot spots for end users. The captive portal is a Web page that the end user is obligated to visit and interact with before access to free Wi-Fi is made available. Example venues may be, but are not limited to, corporate offices for guest login, airports, hotels, coffee shops, etc. A captive portal enables a network administrator to allow authorized users Internet access. In a captive portal network the Wi-Fi authentication is always Open Authentication and real user authorization is carried out through the Web page where the end user interacts to enter login credentials.

[0003] One of the most widely used implementation mechanisms is HTTP redirection. Using HTTP redirection, a gateway on an AP network (or the AP itself with Captive Portal support) hijacks an HTTP request from a connected STA and responds with a redirected URL in the HTTP response. Following this, the HTTP browser on the STA (Wi-Fi client device) opens the redirected URL containing a captive portal login Web page.

[0004] When a device, such as a mobile phone or laptop, running a particular Operating System (OS) connects to a Wi-Fi network with open authentication, the OS on the device carries out steps to detect whether or not the network has a captive portal. The device OS sends out a HTTP-GET request to a corresponding special website hosted by the venue. There is an expected response the device OS knows it is expected to receive when accessing the special website. When the OS device receives the HTTP-GET response, it compares the content of the special website with the expected response. If the content matches, the device OS concludes that there is no captive portal on the Wi-Fi network that it is connected to. When the content does not match, the device OS concludes that there is a captive portal on the Wi-Fi network. This occurs because of the redirection of the HTTP-GET request from the device by the captive portal on the network. The captive portal login page is sent as a response to the HTTP-GET request from the device. The end user can then login with credentials.

[0005] The method described above has several drawbacks. Operating System companies are required to host special websites on the Internet which requires cost to set up and maintain to ensure the website is always up and running. The detection mechanism is based on HTTP protocol and therefore may not be suitable for small embedded devices, such as wearables or Internet of Things (IOT) devices, which typically operate without HTTP protocol. The method relies on HTTP protocol exchange between a host and a hosted HTTP server and is time consuming. Carrying out an HTTP protocol exchange for every Wi-Fi connection also adds traffic to the Internet.

[0006] There is a need for an efficient method for captive portal detection.

[0007] TEEMU KÄRKKÄINEN ET AL, "Enabling ad-hoc-style communication in public WLAN hot-spots", CHALLENGED NETWORKS, ACM, 2 PENN PLAZA, SUITE 701 NEW YORK NY 10121-0701 USA, (20120822), doi:10.1145/2348616.2348623, ISBN 978-1-4503-1284-4, pages 31 - 38, XP058009256, US 2017/111269, US 2015/295885 and DONNELLY M CULLEN PAINLESS SECURITY M, "Captive Portal Detection and Interaction; draft-donnelly-capport-detection-OO.txt", CAPTIVE PORTAL DETECTION AND INTERACTION; DRAFT-DONNELLY-CAPPORT-DETECTION-OO.TXT; INTERNET-DRAFT: CAPTIVE PORTAL WG, INTERNET ENGINEERING TASK FORCE, IETF; STANDARDWORKINGDRAFT, INTERNET SOCIETY (ISOC) 4, RUE DES FALAISES CH- 1205 GENEVA, SWITZERLAND, (20170314), pages 1 - 13, XP015124564 describe methods pertaining to the technological background of the present disclosure.

SUMMARY



[0008] The present invention is recited in the independent claims. Preferred features are recited in the dependent claims.

[0009] A method for detecting a captive portal on a Wi-Fi network, the method is carried out on a device connected to a Wi-Fi network. An Internet Protocol (IP) address is acquired from a dynamic host configuration protocol on the Wi-Fi network and set as a default gateway to Internet. The device generates a random private IP address and attempts a TCP connection, to the random private IP address, on HTTP port:80 or HTTP port 8080. Upon an unsuccessful TCP connection to the random private IP address, a determination may be made that a captive portal has not been detected. Upon a successful TCP connection to the random private IP address, a determination may be made that a captive portal has been detected.

[0010] The random private IP address is not associated with a subnet of the Wi-Fi network. Upon a determination that a captive portal has been detected, an end user of the device is notified about the captive portal. In order to verify the captive portal detection, the method may be applied using a plurality of random private IP addresses that are not associated with a subnet of the Wi-Fi network.

DESCRIPTION OF DRAWINGS



[0011] 

FIG. 1 is a block diagram depicting Wi-Fi access to Internet for a Wi-Fi hotspot in a captive portal network.

FIG. 2 is a flowchart of a method for detecting a captive portal network.

FIG. 3 is a flowchart of a method for verifying detection of a captive portal network.



[0012] Elements and steps in the figures are illustrated for simplicity and clarity and have not necessarily been rendered according to any particular sequence. For example, steps that may be performed concurrently or in different order are illustrated in the figures to help to improve understanding of embodiments of the present disclosure.

DETAILED DESCRIPTION



[0013] The below mentioned embodiments are meant to be examples useful for understanding the invention, which is only defined by the appended claims. In the figures, like reference numbers will be used to illustrate the same components. Those skilled in the art will recognize that the various components set forth herein may be altered without varying from the present disclosure.

[0014] Any one or more of the servers, receivers, or devices described herein include computer executable instructions that may be compiled or interpreted from computer programs created using a variety of programming languages and/or technologies. In general, a processor (such as a microprocessor) receives instructions, for example from a memory, a computer-readable medium, or the like, and executes the instructions. A processing unit includes a non-transitory computer-readable storage medium capable of executing instructions of a software program. The computer readable storage medium may be, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semi-conductor storage device, or any suitable combination thereof. Any one or more the devices herein may rely on firmware, which may require updates from time to time to ensure compatibility with operating systems, improvements and additional functionality, security updates or the like. Connecting and networking servers, receivers or devices may include, but are not limited to, SATA, Wi-Fi, lightning, Ethernet, UFS, 5G, etc.. One or more servers, receivers, or devices may operate using a dedicated operating system, multiple software programs and/or platforms for interfaces such as graphics, audio, wireless networking, enabling applications, integrating hardware of vehicle components, systems, and external devices such as smart phones, tablets, and other systems to name just a few.

[0015] FIG. 1 is a block diagram 100 depicting Wi-Fi access to Internet 102 for a Wi-Fi hotspot 104 in a captive portal network 106. Any one of several devices 108(1), (2), (3)...(n) such as a laptop, tablet, mobile phone, connected vehicle, a head unit in a vehicle, or other connected, embedded device such as a wearable or IoT device may access the Wi-Fi hotspot 104. The captive portal network 106 includes a captive portal server 110 and a Wi-Fi network controller 112. A device attempts connecting to the Internet through the Wi-Fi hotspot. The captive portal network redirects Hypertext Transmission Protocol (HTTP) traffic from the device to the Internet or to any other subnet to the captive portal server running on HTTP Port:80 or HTTP Port:8080. HTTP protocol is based on Transmission Control Protocol (TCP). In order for the HTTP redirection to take place, the device's TCP connection takes place with the captive portal server rather than a server associated with an HTTP server of the website.

[0016] FIG. 2 is a flowchart of a method 200 for detecting a captive portal using the underlying behavior of the captive portal to detect the existence of a captive portal in a network. A device, such as a head unit on a vehicle, initiates 202 a connection to a Wi-Fi network. A Wi-Fi connection is completed 204. The device acquires 206 an IP address from a Dynamic Host Configuration Protocol (DHCP) on the Wi-Fi network. It should be noted that for the example described herein with reference to a head unit on an automotive vehicle, the head unit is a Wi-Fi STA which connects to an external Access Point (AP). However, there are other examples that may be implement the inventive subject matter herein without departing from the scope of the inventive subject matter. For example, for home or small office networks, the DHCP server usually runs on an AP that provides an IP to a connected STA. In a large office or enterprise network, the DHCP server may run on a wired back end network. In any implementation, the captive portal will run on the Wi-Fi AP.

[0017] The device sets the Wi-Fi network as a default gateway 208 in a routing table in order to reach the Internet. The device generates 210 a random private Internet Protocol (IP) address that does not belong to a subnet of the Wi-Fi network. The random private IP address, belonging to a different subnet, is generated to ensure that the generated IP address is within a predetermined range, for example, 10.0.0.0 to 10.255.255.255. A TCP connection to the random private IP address is carried out 212 on HTTP Port:80 and/or HTTP Port:8080. Ports 80 and 8080 are well-known HTTP ports.

[0018] In a network without a captive portal, any traffic to this non-existent randomly generated IP address should get dropped. Also in a network without a captive portal, there will not be an HTTP server running on the non-existent randomly generated IP address. It is highly improbable that the Wi-Fi network is connected to another subnet, that the randomly generated private IP address is valid in any other connected subnet, and that there is an HTTP server running on the device. Also, due to the underlying behavior of a captive portal network, it is known that the captive portal network redirects any HTTP traffic, and therefore any TCP protocol traffic, meant for any destination IP address to the HTTP server running the captive portal login page. Therefore, a determination is made based on whether or not the TCP connection is successful 214.

[0019] As discussed earlier herein, there may be an HTTP server running on the same network, so with a randomly generated IP address in the same subnet, any attempted TCP connection may result in a connection to the wrong HTTP server. Therefore, attempting the TCP connection to a non-existent HTTP server on a random private IP address where it is ensured that no HTTP server is running, any successful connection is due to the existence of a captive portal that has hijacked the TCP connection and redirected it to its own login page. A successful TCP connection 216 indicates a captive portal has been detected. An unsuccessful TCP 218 connection indicates that the Wi-Fi network does not have a captive portal 220. Upon concluding the existence of a captive portal 216, an end user at the device may be notified 222. A notification may be, but is not limited to, a message displayed at the device and presented to a user of the device that the Wi-Fi network has a captive portal.

[0020] Using the method 200 described above, Operating System companies are not required to host special websites on the Internet which results in a cost savings associated with setting up and maintaining the website. The detection mechanism of the method described herein is based on a TCP connection and therefore is suitable for small embedded devices, such as wearables or Internet of Things (IOT) devices. The method 200 is completely based on TCP connection that is within a local network and not the Internet, making it fast and efficient. Also because the TCP connection does not rely on HTTP protocol exchange between a host and a hosted HTTP server for every Wi-Fi connection traffic to the Internet is reduced.

[0021] FIG. 3 is a flow chart depicting a method 300 for verifying the result. Upon making a determination as to whether or not a TCP connection is successful, a TCP connection can be repeated with more than one randomly generated private IP addresses. The device generates 302 a plurality of random IP addresses not belonging to the Wi-Fi subnet. A TCP connection to each random IP address is attempted 304. A determination 306 is made as to whether or not the TCP connections are successful. Upon unsuccessful connections 308, a conclusion is made that there is no captive portal 310. Upon successful connections 312, a conclusion is made that a captive portal has been detected and an end user is notified 314 of the captive portal.

[0022] The specification and figures are illustrative, rather than restrictive. Accordingly, the scope of the inventive subject matter should be determined by the claims.

[0023] Benefits, other advantages and solutions to problems have been described above with regard to particular embodiments.

[0024] The terms "comprise", "comprises", "comprising", "having", "including", "includes" or any variation thereof, are intended to reference a non-exclusive inclusion, such that a process, method, article, composition or apparatus that comprises a list of elements does not include only those elements recited, but may also include other elements not expressly listed or inherent to such process, method, article, composition or apparatus.


Claims

1. A method (200) for detecting a captive portal on a Wi-Fi network, the method carried out on a device (108) having a processing unit including a non-transitory computer-readable storage medium capable of executing instructions of a software program, the method comprising the steps of:

connecting (202, 204) to a Wi-Fi network;

acquiring (206) an Internet Protocol, IP, address from a dynamic host configuration protocol on the Wi-Fi network;

setting (208) the Wi-Fi network IP address as a default gateway to Internet;

generating (210), at the device, a random private IP address that does not belong to a subnet of the Wi-Fi network;

attempting (212) a TCP connection to the random private IP address on HTTP port:80 or HTTP port:8080;

upon an unsuccessful TCP connection (218) to the random private IP address, making a determination that a captive portal has not been detected (220); and

upon a successful TCP connection (216) to the random private IP address, making a determination that a captive portal has been detected.


 
2. The method as claimed in claim 1 further comprising, in case the captive portal has been detected, the step of notifying a user of the device that the Wi-Fi network has the captive portal.
 
3. The method as claimed in claim 2 wherein the step of notifying a user of the device further comprises displaying a message at the device indicating that the captive portal exists.
 
4. The method as claimed in claim 1 wherein the step of making a determination that a captive portal has been detected further comprises step of verifying the captive portal has been detected.
 
5. The method as claimed in claim 4 wherein the step of verifying the captive portal has been detected further comprises the steps of:

generating, at the device, a plurality of random private IP addresses, wherein each random private IP address in the plurality of random private IP addresses does not belong to a subnet of the Wi-Fi network;

attempting TCP connections to each of the plurality of random private IP addresses on HTTP port:80 or HTTP port:8080;

upon an unsuccessful TCP connection, making a determination that a captive portal has not been detected; and

upon successful TCP connections of each of the plurality of random private IP addresses, making a determination that a captive portal has been detected.


 
6. The method of claim 1, wherein the device is a head unit of a vehicle, wherein the Wi-Fi network IP address is set as the default gateway to Internet on a routing table at the head unit.
 
7. The method as claimed in claim 6 further comprising, in case a captive portal has been detected, the step of notifying a user of the head unit that the Wi-Fi network has a captive portal.
 
8. The method as claimed in claim 7 wherein the step of notifying a user of the device further comprises displaying a message at the device indicating that a captive portal exists.
 
9. The method as claimed in claim 6 further comprises the steps of:

generating, at the head unit, a plurality of random private IP addresses, each of which does not belong to a subnet of the Wi-Fi network;

attempting TCP connections to each of the random private IP addresses in the plurality of random private IP addresses on port:80 or HTTP port:8080;

upon an unsuccessful TCP connection, making a determination that no captive portal is associated with the Wi-Fi network;

upon successful TCP connections of each of the plurality of random private IP addresses, verifying the determination that a captive portal is associated with the Wi-Fi network.


 
10. A computer program product comprising a computer-readable storage medium including instructions that, when executed by a processor, cause the processor to perform the method of any preceding claim.
 


Ansprüche

1. Verfahren (200)zur Erkennung eines Captive Portal auf einem Wi-Fi-Netzwerk, wobei das Verfahren auf einer Vorrichtung (108) ausgeführt wird, die eine Verarbeitungseinheit aufweist, die ein nichtflüchtiges, computerlesbares Speichermedium beinhaltet, das in der Lage ist, Anweisungen eines Softwareprogramms auszuführen, wobei das Verfahren die folgenden Schritte umfasst:

Verbinden (202, 204) mit einem Wi-Fi-Netzwerk;

Erhalten (206) einer Internetprotokoll-Adresse (IP-Adresse) von einem Dynamic-Host-Configuration-Protokoll auf dem Wi-Fi-Netzwerk;

Einstellen (208) der Wi-Fi-Netzwerk-IP-Adresse als Standardgateway für das Internet;

Erzeugen (210), auf der Vorrichtung, einer zufälligen privaten IP-Adresse, die nicht zu einem Teilnetz des Wi-Fi-Netzwerks gehört;

Versuchen (212), eine TCP-Verbindung mit der zufälligen privaten IP-Adresse auf HTTP-Port 80 oder HTTP-Port 8080 herzustellen;

nach einer erfolglosen TCP-Verbindung (218) mit der zufälligen privaten IP-Adresse, Treffen einer Feststellung, dass ein Captive Portal nicht erkannt (220) wurde; und

nach einer erfolgreichen TCP-Verbindung (216) mit der zufälligen privaten IP-Adresse, Treffen einer Feststellung, dass ein Captive Portal erkannt wurde.


 
2. Verfahren nach Anspruch 1, ferner den Schritt umfassend, in dem ein Benutzer der Vorrichtung, im Fall, dass das Captive Portal erkannt wurde, benachrichtigt wird, dass das Wi-Fi-Netzwerk das Captive Portal aufweist.
 
3. Verfahren nach Anspruch 2, wobei der Schritt, in dem ein Benutzer der Vorrichtung benachrichtigt wird, ferner umfasst, dass eine Nachricht auf der Vorrichtung angezeigt wird, die angibt, dass das Captive Portal existiert.
 
4. Verfahren nach Anspruch 1, wobei der Schritt, in dem eine Feststellung getroffen wird, dass ein Captive Portal erkannt wurde, ferner einen Schritt umfasst, in dem verifiziert wird, dass das Captive Portal erkannt wurde.
 
5. Verfahren nach Anspruch 4, wobei der Schritt, in dem verifiziert wird, dass das Captive Portal erkannt wurde, ferner folgende Schritte umfasst:

Erzeugen, auf der Vorrichtung, einer Vielzahl von zufälligen privaten IP-Adressen, wobei jede zufällige private IP-Adresse in der Vielzahl von zufälligen privaten IP-Adressen nicht zu einem Teilnetz des Wi-Fi-Netzwerks gehört;

Versuchen, TCP-Verbindungen mit jeder von der Vielzahl von zufälligen privaten IP-Adressen auf HTTP-Port 80 oder HTTP-Port 8080 herzustellen;

nach einer erfolglosen TCP-Verbindung, Treffen einer Feststellung, dass ein Captive Portal nicht erkannt wurde; und

nach erfolgreichen TCP-Verbindungen von jeder von der Vielzahl von zufälligen privaten IP-Adressen, Treffen einer Feststellung, dass ein Captive Portal erkannt wurde.


 
6. Verfahren nach Anspruch 1, wobei die Vorrichtung eine Kopfeinheit eines Fahrzeugs ist, wobei die Wi-Fi-Netzwerk-IP-Adresse als Standardgateway für das Internet auf einer Routing-Tabelle auf der Kopfeinheit eingestellt ist.
 
7. Verfahren nach Anspruch 6, ferner den Schritt umfassend, in dem im Fall, dass das Captive Portal erkannt wurde, ein Benutzer der Kopfeinheit benachrichtigt wird, dass das Wi-Fi-Netzwerk ein Captive Portal aufweist.
 
8. Verfahren nach Anspruch 7, wobei der Schritt, in dem ein Benutzer der Vorrichtung benachrichtigt wird, ferner umfasst, dass eine Nachricht auf der Vorrichtung angezeigt wird, die angibt, dass ein Captive Portal existiert.
 
9. Verfahren nach Anspruch 6, ferner folgende Schritte umfassend:

Erzeugen, auf der Kopfeinheit, einer Vielzahl von zufälligen privaten IP-Adressen, von denen jede nicht zu einem Teilnetz des Wi-Fi-Netzwerks gehört;

Versuchen, TCP-Verbindungen mit jeder der zufälligen privaten IP-Adressen in der Vielzahl von zufälligen privaten IP-Adressen auf Port 80 oder HTTP-Port 8080 herzustellen;

nach einer erfolglosen TCP-Verbindung, Treffen einer Feststellung, dass kein Captive Portal dem Wi-Fi-Netzwerk zugeordnet ist;

nach erfolgreichen TCP-Verbindungen von jeder von der Vielzahl von zufälligen privaten IP-Adressen, Verifizieren der Feststellung, dass ein Captive Portal dem Wi-Fi-Netzwerk zugeordnet ist.


 
10. Computerprogrammprodukt, ein computerlesbares Speichermedium umfassend, das Anweisungen beinhaltet, die, wenn sie durch einen Prozessor ausgeführt werden, dazu führen, dass der Prozessor das Verfahren nach einem der vorhergehenden Ansprüche durchführt.
 


Revendications

1. Procédé (200) de détection d'un portail captif dans un réseau Wi-Fi, le procédé étant effectué sur un dispositif (108) ayant une unité de traitement incluant un support de stockage non transitoire lisible par ordinateur capable d'exécuter des instructions d'un programme logiciel, le procédé comprenant les étapes consistant à :

se connecter (202, 204) à un réseau Wi-Fi ;

acquérir (206) une adresse de Protocole Internet, IP, depuis un protocole de configuration d'hôte dynamique dans le réseau Wi-Fi ;

régler (208) l'adresse IP de réseau Wi-Fi en tant que passerelle par défaut à l'Internet ;

générer (210), au niveau du dispositif, une adresse IP privée aléatoire qui n'appartient pas à un sous-réseau du réseau Wi-Fi ;

tenter d'établir (212) une connexion TCP à l'adresse IP privée aléatoire sur un port HTTP:80 ou un port HTTP:8080 ;

lors d'une connexion TCP non réussie (218) à l'adresse IP privée aléatoire, déterminer qu'un portail captif n'a pas été détecté (220) ; et

lors d'une connexion TCP réussie (216) à l'adresse IP privée aléatoire, déterminer qu'un portail captif a été détecté.


 
2. Procédé selon la revendication 1, comprenant en outre, en cas où le portail captif a été détecté, l'étape consistant à notifier à un utilisateur du dispositif que le réseau Wi-Fi a le portail captif.
 
3. Procédé selon la revendication 2, dans lequel l'étape de notification à un utilisateur du dispositif comprend en outre l'affichage d'un message au niveau du dispositif indiquant que le portail captif existe.
 
4. Procédé selon la revendication 1, dans lequel l'étape de détermination qu'un portail captif a été détecté comprend en outre une étape consistant à vérifier que le portail captif a été détecté.
 
5. Procédé selon la revendication 4, dans lequel l'étape de vérification que le portail captif a été détecté comprend en outre les étapes consistant à :

générer, au niveau du dispositif, une pluralité d'adresses IP privées aléatoires, dans lequel aucune adresse IP privée aléatoire dans la pluralité d'adresses IP privées aléatoires n'appartient à un sous-réseau du réseau Wi-Fi ;

tenter d'établir des connexions TCP à chacune d'une pluralité d'adresses IP privées aléatoires sur un port HTTP:80 ou un port HTTP:8080 ;

lors d'une connexion TCP non réussie, déterminer qu'un portail captif n'a pas été détecté ; et

lors de connexions TCP réussies de chacune de la pluralité d'adresses IP privées aléatoires, déterminer qu'un portail captif a été détecté.


 
6. Procédé selon la revendication 1, dans lequel le dispositif est une unité de tête d'un véhicule, dans lequel l'adresse IP de réseau Wi-Fi est réglée en tant que passerelle par défaut à l'Internet sur une table de routage dans l'unité de tête.
 
7. Procédé selon la revendication 6, comprenant en outre, dans le cas où un portail captif a été détecté, l'étape consistant à notifier à un utilisateur de l'unité de tête que le réseau Wi-Fi a un portail captif.
 
8. Procédé selon la revendication 7, dans lequel l'étape de notification à un utilisateur du dispositif comprend en outre l'affichage d'un message au niveau du dispositif indiquant qu'un portail captif existe.
 
9. Procédé selon la revendication 6, comprenant en oute les étapes consistant à :

générer, au niveau de l'unité de tête, une pluralité d'adresses IP privées aléatoires, dont aucune n'appartient à un sous-réseau du réseau Wi-Fi ;

tenter d'établir une connexion TCP à chacune des adresses IP privées aléatoires dans la pluralité d'adresses IP privées aléatoires sur un port:80 ou un port HTTP:8080 ;

lors d'une connexion TCP non réussie, déterminer qu'aucun portail captif n'est associé au réseau Wi-Fi ;

lors de connexions TCP réussies de chacune de la pluralité d'adresses IP privées aléatoires, vérifier la détermination qu'un portail captif est associé au réseau Wi-Fi.


 
10. Produit-programme d'ordinateur comprenant un support de stockage lisible par ordinateur incluant des instructions qui, lorsqu'elles sont exécutées par un processeur, amènent le processeur à réaliser le procédé selon l'une quelconque des revendications précédentes.
 




Drawing














Cited references

REFERENCES CITED IN THE DESCRIPTION



This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description




Non-patent literature cited in the description