Udpcast

udpcast@udpcast.linux.lu

551 discussions

by julien soula

hello, we found a problem in using updcast in a context of multi-routers when the rdv-addr is not multicast. Indeed, in this case, the multicast ttl must be greater than 1 (--ttl). But it is only assign during the processing of rdv-addr and only if rdv-addr is a multicast IP : udps-negotiate.c: /* Only do the following if controlMcastAddr is indeed an mcast address ... */ if(isMcastAddress(&net_config->controlMcastAddr)) { setMcastDestination(sock[0], net_config->net_if, &net_config->controlMcastAddr); setTtl(sock[0], net_config->ttl); But it is not assign during the processing of data-addr : udps-negotiate.c: if(isMcastAddress(&net_config->dataMcastAddr)) setMcastDestination(sock, net_config->net_if, &net_config->dataMcastAddr); Therefore, if rdv-addr is unicast then TTL remains to 1. So I suggest to patch the code this way : - if(isMcastAddress(&net_config->dataMcastAddr)) + if(isMcastAddress(&net_config->dataMcastAddr)) { setMcastDestination(sock, net_config->net_if, &net_config->dataMcastAddr); + setTtl(sock, net_config->ttl); + } Best regards, -- Julien Soula, Ingenieur Reseau, DSI/ULR2694, Universite de Lille, tel (0)3 20 62 34 55

1 month, 2 weeks

Regression in Udpcast 20211207

by Robert Theron Brockman II

Howdy! I found a strange bug in the new version of Udpcast. When sending packets at speeds over around 80m, the program locks up. I traced the problem to the doRateLimit function in rate-limit.c (I've added some printfs): sleepTime = rateLimit->queueSize * 8 * MILLION / rateLimit->bitrate; printf("sleepTime1 %lu\n",sleepTime); printf("rateLimit->queueSize %lu\n",rateLimit->queueSize); if(sleepTime > 40000 || rateLimit->queueSize >= 100000) { printf("sleepTime2 %lu\n",sleepTime); sleepTime -= 10000; printf("sleepTime3 %lu\n",sleepTime); printf("sleepTime3 % 10000 %u\n",sleepTime % 10000); sleepTime -= sleepTime % 10000; printf("sleepTime4 %lu\n",sleepTime); usleep((useconds_t)sleepTime); } What is happening is that sometimes rateLimit->queueSize >= 100000 but sleepTime is small, so subtracting 10000 from it wraps around to near maxint. The strange thing is that when the program then does sleepTime -= sleepTime % 10000 the result is *different* from the 20200328 version because of the change to long unsigned integers. In the old version sleepTime would become zero, but now it stays huge, leading to an extremely long usleep. Here is the old behavior: sleepTime1 1338 rateLimit->queueSize 100350 sleepTime2 1338 sleepTime3 4294958634 sleepTime3 % 10000 4294958634 sleepTime4 0 Here is the new behavior (which hangs): sleepTime1 1344 rateLimit->queueSize 100800 sleepTime2 1344 sleepTime3 18446744073709542960 sleepTime3 % 10000 2960 sleepTime4 18446744073709540000 It looks to me like the older version actually had offsetting bugs: sleepTime % 10000 *should* return a value less than 10000 but in the old code for some reason it just returned sleepTime, which then subtracted from itself gave zero. In the new version the wraparound error from the sleepTime -= 10000 has been exposed, causing the hang. Anyway, hopefully this isn't too hard to fix: your program is super-useful for us, and the old version merrily blasts udp packets at gigabit speeds! Thanks, Robert II

2 months, 2 weeks

musl build failure

by Fabrice Fontaine

Dear all, Please find attached a patch to fix a musl build failure. Best Regards, Fabrice

9 months, 3 weeks

Udpcast 20211207 released

by Alain Knaff

Hello all, Udpcast 20211207 is released. The most important changes are: - --max-bitrate now works with bitrates greater than 2**31 - Use newest busybox (1.33.2) and kernel (5.10.83) - Lots of compiler warnings and variable type issues have been resolved Regards, Alain

1 year, 5 months

Using UDPcast in a C program directly as a function

by cyber work

Dear sir, I would like to start by thanking you for your work on udpcast as it has been very useful for a lot of people and companies. I am reaching out in order to get some insight on how to use udpcast (sender & receiver) directly in C code without executing it from a bash call. To be clear, I would like to know if there is some kind of documentation on how to use these programs in C as functions that I could call. So far, every program that I have seen uses udp-sender and udp-receiver by a bash call inside a C or python code. This does not suit me because it slows significantly the speed of the program. Thanks a lot

1 year, 10 months

option --nokbd doesn't send data

by Luke Robison

I am trying to push data through a one-way pipe in an automated way using udp-sender and udp-receiver. I have a working example, but can't get the --nokbd option to work on the sending side. Working Sender: yes | ~/udp-sender --async --fec 8x6/64 --max-bitrate 500M -f tmp_send_tarball.tar Receiver Command: ~/udp-receiver --pipe ~/rx_hook.sh --nokbd But notice I have to pipe the "yes" command into udp-sender to trigger the start from udp-sender. When instead I use --nokbd on the receiver, it hangs waiting for something after the control message. True to the documentation, it doesn't ask nor accept input, but it seems to fall into a default of "don't send" rather than a default of "send immediately" as I would expect. $ ~/udp-sender --async --fec 8x6/64 --max-bitrate 500M -f .tmp_send_tarball.tar --nokbd stripes=8 redund=6 stripesize=64 Udp-sender 20200328 Using mcast address 234.14.136.217 UDP sender for .tmp_send_tarball.tar at 10.14.136.217 on eno3 Broadcasting control to 10.14.143.255 <hangs here...> Am I missing something? Respectfully, Luke

1 year, 10 months

Two or more clients drops bandwith by 2 orders of magnitude

by Brent Kimberley

William Please ensure you are using UDP/IGMP. Brent Hi, (I hope this list is still active) I am a newbie. I am testing multicast support on three computers connected through a gigabit switch. When only the server, ran as (rand.bin is a 1Gb file) udp-sender --interface eth1 --file rand.bin and ONE client udp-receiver --file rand.bin are connected, the bandwidth is around 937.32 Mbps, which is very good. But with two or more clients if consistently drops to 11 Mbps I would expect to bandwidth to decrease as 1/N, where N is the number of clients. What am I missing? I am using a dumb switch. Thanks -- Best regards / Cordialmente, William-Fernando Oquendo -------------------------- Este correo puede carecer de tildes o e?es debido al teclado. THIS MESSAGE IS FOR THE USE OF THE INTENDED RECIPIENT(S) ONLY AND MAY CONTAIN INFORMATION THAT IS PRIVILEGED, PROPRIETARY, CONFIDENTIAL, AND/OR EXEMPT FROM DISCLOSURE UNDER ANY RELEVANT PRIVACY LEGISLATION. No rights to any privilege have been waived. If you are not the intended recipient, you are hereby notified that any review, re-transmission, dissemination, distribution, copying, conversion to hard copy, taking of action in reliance on or other use of this communication is strictly prohibited. If you are not the intended recipient and have received this message in error, please notify me by return e-mail and delete or destroy all copies of this message.

1 year, 11 months

Two or more clients drops bandwith by 2 orders of magnitude

by William Oquendo

Hi, (I hope this list is still active) I am a newbie. I am testing multicast support on three computers connected through a gigabit switch. When only the server, ran as (rand.bin is a 1Gb file) udp-sender --interface eth1 --file rand.bin and ONE client udp-receiver --file rand.bin are connected, the bandwidth is around 937.32 Mbps, which is very good. But with two or more clients if consistently drops to 11 Mbps I would expect to bandwidth to decrease as 1/N, where N is the number of clients. What am I missing? I am using a dumb switch. Thanks -- Best regards / Cordialmente, William-Fernando Oquendo -------------------------- Este correo puede carecer de tildes o eñes debido al teclado.

1 year, 11 months

UDP CAST Windows X64

by yms

Hi ALL I am a IT teacher in Taiwan. I use Udpcast Windows version + WinPE to maintain our PC & NB for a lon time. Udpcast is a very useful tool and helpful, thanks for all your works. We now encounter an upgrade to 86-x64. Can anyone help to compile Udpcast Windows 86-x64 version? Sincerely MS. Yang. 嘉義縣教育網路中心 05-2304464

1 year, 11 months

Udpcast 20200328 released

by Alain Knaff

Hello all, Udpcast 20200328 is released. The most important changes are: - Use newest busybox (1.31.1) and kernel (5.0.21) - Udp-sender now returns a non-zero exit status if a timeout expires at start - Fix compiler warnings and various typoes - Fixes for Mingw - Fix issues in assembly in fec.c Unfortunately, due to bigger sizes produced by today's kernels, and due to lack of usage, I dropped floppy support. Similarly, Etherboot support has been dropped. Indeed PXE is the recommended net boot solution today. Regards, Alain

3 years, 2 months

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Udpcast