* [PATCH v2] pasta.c: modify hostname when detaching new namespace [not found] <20240520083343.10973-1-contact@danishpraka.sh> @ 2024-07-30 6:01 ` Danish Prakash 2024-07-30 17:09 ` Stefano Brivio 0 siblings, 1 reply; 2+ messages in thread From: Danish Prakash @ 2024-07-30 6:01 UTC (permalink / raw) To: passt-dev, sbrivio; +Cc: Danish Prakash When invoking pasta without any arguments, it's difficult to tell whether we are in the new namespace or not leaving users a bit confused. This change modifies the host namespace to add a prefix "pasta-" to make it a bit more obvious. Signed-off-by: Danish Prakash <contact@danishpraka.sh> --- pasta.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/pasta.c b/pasta.c index 31e1e000ee1b..7ce502d3f299 100644 --- a/pasta.c +++ b/pasta.c @@ -50,6 +50,8 @@ #include "netlink.h" #include "log.h" +#define HOSTNAME_PREFIX "pasta-" + /* PID of child, in case we created a namespace */ int pasta_child_pid; @@ -178,6 +180,7 @@ struct pasta_spawn_cmd_arg { */ static int pasta_spawn_cmd(void *arg) { + char hostname[HOST_NAME_MAX + 1] = HOSTNAME_PREFIX; const struct pasta_spawn_cmd_arg *a; sigset_t set; @@ -188,6 +191,13 @@ static int pasta_spawn_cmd(void *arg) if (write_file("/proc/sys/net/ipv4/ping_group_range", "0 0")) warn("Cannot set ping_group_range, ICMP requests might fail"); + if (!gethostname(hostname + sizeof(HOSTNAME_PREFIX) - 1, HOST_NAME_MAX + 1 - + sizeof(HOSTNAME_PREFIX)) || errno == ENAMETOOLONG) { + hostname[HOST_NAME_MAX] = '\0'; + if (sethostname(hostname, strlen(hostname))) + warn("Unable to set pasta-prefixed hostname"); + } + /* Wait for the parent to be ready: see main() */ sigemptyset(&set); sigaddset(&set, SIGUSR1); -- @@ -50,6 +50,8 @@ #include "netlink.h" #include "log.h" +#define HOSTNAME_PREFIX "pasta-" + /* PID of child, in case we created a namespace */ int pasta_child_pid; @@ -178,6 +180,7 @@ struct pasta_spawn_cmd_arg { */ static int pasta_spawn_cmd(void *arg) { + char hostname[HOST_NAME_MAX + 1] = HOSTNAME_PREFIX; const struct pasta_spawn_cmd_arg *a; sigset_t set; @@ -188,6 +191,13 @@ static int pasta_spawn_cmd(void *arg) if (write_file("/proc/sys/net/ipv4/ping_group_range", "0 0")) warn("Cannot set ping_group_range, ICMP requests might fail"); + if (!gethostname(hostname + sizeof(HOSTNAME_PREFIX) - 1, HOST_NAME_MAX + 1 - + sizeof(HOSTNAME_PREFIX)) || errno == ENAMETOOLONG) { + hostname[HOST_NAME_MAX] = '\0'; + if (sethostname(hostname, strlen(hostname))) + warn("Unable to set pasta-prefixed hostname"); + } + /* Wait for the parent to be ready: see main() */ sigemptyset(&set); sigaddset(&set, SIGUSR1); -- 2.45.2 ^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] pasta.c: modify hostname when detaching new namespace 2024-07-30 6:01 ` [PATCH v2] pasta.c: modify hostname when detaching new namespace Danish Prakash @ 2024-07-30 17:09 ` Stefano Brivio 0 siblings, 0 replies; 2+ messages in thread From: Stefano Brivio @ 2024-07-30 17:09 UTC (permalink / raw) To: Danish Prakash; +Cc: passt-dev On Tue, 30 Jul 2024 11:31:23 +0530 Danish Prakash <contact@danishpraka.sh> wrote: > When invoking pasta without any arguments, it's difficult > to tell whether we are in the new namespace or not leaving > users a bit confused. This change modifies the host namespace > to add a prefix "pasta-" to make it a bit more obvious. > > Signed-off-by: Danish Prakash <contact@danishpraka.sh> Thanks for following up with this! I just applied it with some coding style fixes: > --- > pasta.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/pasta.c b/pasta.c > index 31e1e000ee1b..7ce502d3f299 100644 > --- a/pasta.c > +++ b/pasta.c > @@ -50,6 +50,8 @@ > #include "netlink.h" > #include "log.h" > > +#define HOSTNAME_PREFIX "pasta-" > + > /* PID of child, in case we created a namespace */ > int pasta_child_pid; > > @@ -178,6 +180,7 @@ struct pasta_spawn_cmd_arg { > */ > static int pasta_spawn_cmd(void *arg) > { > + char hostname[HOST_NAME_MAX + 1] = HOSTNAME_PREFIX; > const struct pasta_spawn_cmd_arg *a; > sigset_t set; > > @@ -188,6 +191,13 @@ static int pasta_spawn_cmd(void *arg) > if (write_file("/proc/sys/net/ipv4/ping_group_range", "0 0")) > warn("Cannot set ping_group_range, ICMP requests might fail"); > > + if (!gethostname(hostname + sizeof(HOSTNAME_PREFIX) - 1, HOST_NAME_MAX + 1 - This exceeds 80 columns. > + sizeof(HOSTNAME_PREFIX)) || errno == ENAMETOOLONG) { This is indented with spaces instead of tabs, and "errno == ENAMETOOLONG" is not aligned with !gethostname(), despite logically being at the same level. See also my previous emails about this: https://archives.passt.top/passt-dev/20240523162347.44e6faf3@elisabeth/ https://archives.passt.top/passt-dev/20240524193918.151fd2fc@elisabeth/ > + hostname[HOST_NAME_MAX] = '\0'; And this should be aligned with the rest of the clause body, that is, indented one level on top of the conditional. With (two) tabs, not spaces. > + if (sethostname(hostname, strlen(hostname))) > + warn("Unable to set pasta-prefixed hostname"); > + } > + > /* Wait for the parent to be ready: see main() */ > sigemptyset(&set); > sigaddset(&set, SIGUSR1); -- Stefano ^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2024-07-30 17:10 UTC | newest] Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- [not found] <20240520083343.10973-1-contact@danishpraka.sh> 2024-07-30 6:01 ` [PATCH v2] pasta.c: modify hostname when detaching new namespace Danish Prakash 2024-07-30 17:09 ` Stefano Brivio
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