HTML rendering created 2025-09-06 byMichael Kerrisk, author ofThe Linux Programming Interface. For details of in-depthLinux/UNIX system programming training courses that I teach, lookhere. Hosting byjambit GmbH. |  |
NAME |SYNOPSIS |DESCRIPTION |RETURN VALUE |NOTES |HISTORY |SEE ALSO |COLOPHON | |
SD_BUS_Q...DER_CREDS(3) sd_bus_query_sender_credsSD_BUS_Q...DER_CREDS(3)sd_bus_query_sender_creds, sd_bus_query_sender_privilege - Query bus message sender credentials/privileges
#include <systemd/sd-bus.h>int sd_bus_query_sender_creds(sd_bus_message *m, uint64_tmask,sd_bus_creds **creds);sd_bus_error* sd_bus_query_sender_privilege(sd_bus_message *m,intcapability);
sd_bus_query_sender_creds()returns the credentials of the messagem. Themask parameter is a combo ofSD_BUS_CREDS_*flags that indicate which credential info the caller is interested in. Seesd_bus_creds_new_from_pid(3) for a list of possible flags. First, this message checks if the requested credentials are attached to the message itself. If not, but the message contains the pid of the sender and the caller specified theSD_BUS_CREDS_AUGMENTflag, this function tries to figure out the missing credentials via other means (starting from the pid). If the PID is not available but the message has a sender, this function callssd_bus_get_name_creds(3) to get the requested credentials. If the message has no sender (when a direct connection is used), this function callssd_bus_get_owner_creds(3) to get the requested credentials. On success, the requested credentials are stored increds. Ownership of the credentials object increds is transferred to the caller and should be freed by callingsd_bus_creds_unref(3).sd_bus_query_sender_privilege()checks if the messagem has the requested privileges. Ifcapability is a non-negative integer, this function checks if the message has the capability with the same value. Seecapabilities(7) for a list of capabilities. Ifcapability is a negative integer, this function returns whether the sender of the message runs as the same user as the receiver of the message, or if the sender of the message runs as root and the receiver of the message does not run as root. On success and if the message has the requested privileges, this function returns a positive integer. If the message does not have the requested privileges, this function returns zero.
On success, these functions return a non-negative integer. On failure, they return a negative errno-style error code.Errors Returned errors may indicate the following problems:-EINVAL The messagem or an output parameter isNULL. Added in version 246.-ENOTCONN The bus ofm is not connected. Added in version 246.-ECHILD The bus ofm was created in a different process, library or module instance. Added in version 246.-EPERM The messagem is not sealed. Added in version 246.
Functions described here are available as a shared library, which can be compiled against and linked to with thelibsystemd pkg-config(1) file. The code described here usesgetenv(3), which is declared to be not multi-thread-safe. This means that the code calling the functions described here must not callsetenv(3) from a parallel thread. It is recommended to only do calls tosetenv()from an early phase of the program when no other threads have been started.
sd_bus_query_sender_creds()andsd_bus_query_sender_privilege() were added in version 246.
systemd(1),sd-bus(3),sd_bus_creds_new_from_pid(3),sd_bus_get_name_creds(3),sd_bus_get_owner_creds(3),sd_bus_creds_unref(3),capabilities(7)
This page is part of thesystemd (systemd system and service manager) project. Information about the project can be found at ⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a bug report for this manual page, see ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩. This page was obtained from the project's upstream Git repository ⟨https://github.com/systemd/systemd.git⟩ on 2025-08-11. (At that time, the date of the most recent commit that was found in the repository was 2025-08-11.) If you discover any rendering problems in this HTML version of the page, or you believe there is a better or more up-to-date source for the page, or you have corrections or improvements to the information in this COLOPHON (which isnot part of the original manual page), send a mail to man-pages@man7.orgsystemd 258~rc2SD_BUS_Q...DER_CREDS(3)Pages that refer to this page:sd-bus(3), sd_bus_add_object(3), systemd.directives(7), systemd.index(7)
HTML rendering created 2025-09-06 byMichael Kerrisk, author ofThe Linux Programming Interface. For details of in-depthLinux/UNIX system programming training courses that I teach, lookhere. Hosting byjambit GmbH. | |