This commit is contained in:
Oleksandr Natalenko 2023-11-29 21:13:44 -07:00 committed by GitHub
commit a6fb980120
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GPG Key ID: 4AEE18F83AFDEB23
5 changed files with 60 additions and 5 deletions

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@ -51,6 +51,11 @@
# include <selinux/selinux.h>
#endif
#ifdef HAVE_LIBCAPNG
#include <stdbool.h>
#include <cap-ng.h>
#endif
#include "common.h"
/* The raw header used when not using DNS protocol */
@ -103,12 +108,60 @@ int setgroups(int count, int *groups)
#ifndef WINDOWS32
void
check_superuser(void)
check_privileges(char *username, int port)
{
#if defined HAVE_LIBCAPNG
bool capable = true;
if (capng_get_caps_process() == -1) {
warnx("Unable to get capabilities");
exit(-1);
}
if (!capng_have_capability(CAPNG_EFFECTIVE, CAP_NET_ADMIN)) {
warnx("capabilities: CAP_NET_ADMIN required");
capable = false;
}
if (port) {
unsigned short int ip_unprivileged_port_start = 1024;
FILE *file = fopen("/proc/sys/net/ipv4/ip_unprivileged_port_start", "r");
if (!file) {
warnx("sysctl: unable to get ip_unprivileged_port_start value");
// do not bail out here in case systemd.service has ProcSubset=pid set
} else {
fscanf(file, "%hu", &ip_unprivileged_port_start);
fclose(file);
}
if (port < ip_unprivileged_port_start &&
!capng_have_capability(CAPNG_EFFECTIVE, CAP_NET_BIND_SERVICE)) {
warnx("capabilities: CAP_NET_BIND_SERVICE required");
capable = false;
}
}
if (username) {
if (!capng_have_capability(CAPNG_EFFECTIVE, CAP_SETUID)) {
warnx("capabilities: CAP_SETUID required");
capable = false;
}
if (!capng_have_capability(CAPNG_EFFECTIVE, CAP_SETGID)) {
warnx("capabilities: CAP_SETGID required");
capable = false;
}
}
if (!capable) {
exit(-1);
}
#else
if (geteuid() != 0) {
warnx("Run as root and you'll be happy.");
exit(-1);
}
#endif
}
#endif

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@ -105,11 +105,11 @@ enum connection {
};
#ifdef WINDOWS32
static inline void check_superuser(void)
static inline void check_privileges(char *, int)
{
}
#else
void check_superuser(void);
void check_privileges(char *, int);
#endif
char *format_addr(struct sockaddr_storage *sockaddr, int sockaddr_len);
int get_addr(char *, int, int, int, struct sockaddr_storage *);

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@ -279,7 +279,7 @@ int main(int argc, char **argv)
}
}
check_superuser();
check_privileges(username, 0);
argc -= optind;
argv += optind;

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@ -2519,7 +2519,7 @@ main(int argc, char **argv)
argc -= optind;
argv += optind;
check_superuser();
check_privileges(username, port);
if (argc != 2)
usage();

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@ -23,6 +23,7 @@ link)
"$PKG_CONFIG" --exists libselinux && FLAGS="$FLAGS $($PKG_CONFIG --libs libselinux)";
"$PKG_CONFIG" --exists libsystemd-daemon && FLAGS="$FLAGS $($PKG_CONFIG --libs libsystemd-daemon)";
"$PKG_CONFIG" --exists libsystemd && FLAGS="$FLAGS $($PKG_CONFIG --libs libsystemd)";
"$PKG_CONFIG" --exists libcap-ng && FLAGS="$FLAGS $($PKG_CONFIG --libs libcap-ng)";
echo $FLAGS;
;;
esac
@ -46,6 +47,7 @@ cflags)
"$PKG_CONFIG" --exists libselinux && FLAGS="$FLAGS -DHAVE_SETCON";
"$PKG_CONFIG" --exists libsystemd-daemon && FLAGS="$FLAGS -DHAVE_SYSTEMD";
"$PKG_CONFIG" --exists libsystemd && FLAGS="$FLAGS -DHAVE_SYSTEMD";
"$PKG_CONFIG" --exists libcap-ng && FLAGS="$FLAGS -DHAVE_LIBCAPNG";
echo $FLAGS;
;;
GNU/kFreeBSD|GNU)