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#include "env_info.h"
#include <pwd.h> // for getpwuid_r, passwd
#include <stdlib.h> // for rand, free, mblen, size_t, exit
#include <string.h>
#include <unistd.h> // for gethostname, getuid, read, sysconf
#include "logging.h"
#include "mlock_page.h"
#include "util.h"
int GetHostName(char* hostname_buf, size_t hostname_buflen) {
if (gethostname(hostname_buf, hostname_buflen)) {
LogErrno("gethostname");
return 0;
}
hostname_buf[hostname_buflen - 1] = 0;
return 1;
}
int GetUserName(char* username_buf, size_t username_buflen) {
struct passwd* pwd = NULL;
struct passwd pwd_storage;
char* pwd_buf;
long pwd_bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
if (pwd_bufsize < 0) {
pwd_bufsize = 1 << 20;
}
pwd_buf = malloc((size_t)pwd_bufsize);
if (!pwd_buf) {
LogErrno("malloc(pwd_bufsize)");
return 0;
}
if (MLOCK_PAGE(pwd_buf, pwd_bufsize) < 0) {
// We continue anyway, as very likely getpwuid_r won't retrieve a password
// hash on modern systems.
LogErrno("mlock");
}
getpwuid_r(getuid(), &pwd_storage, pwd_buf, (size_t)pwd_bufsize, &pwd);
if (!pwd) {
LogErrno("getpwuid_r");
free(pwd_buf);
return 0;
}
if (strlen(pwd->pw_name) >= username_buflen) {
Log("Username too long: got %d, want < %d", (int)strlen(pwd->pw_name),
(int)username_buflen);
free(pwd_buf);
return 0;
}
strncpy(username_buf, pwd->pw_name, username_buflen);
username_buf[username_buflen - 1] = 0;
explicit_bzero(pwd_buf, pwd_bufsize);
free(pwd_buf);
return 1;
}
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