inline char* readstring(){
//Read a Pascal string with 1 length byte
unsigned length = readint8();
char *string = (char*) malloc(length+1);
readbytes(string, length);
string[length] = '\0';
return string;
}
static struct nsenter_config process_nl_attributes(int pipenum, char *data, int data_size)
{
struct nsenter_config config = {0};
struct nlattr *nlattr;
int payload_len;
int start = 0;
config.consolefd = -1;
while (start < data_size) {
nlattr = (struct nlattr *)(data + start);
start += NLA_HDRLEN;
payload_len = nlattr->nla_len - NLA_HDRLEN;
if (nlattr->nla_type == CLONE_FLAGS_ATTR) {
config.cloneflags = readint32(data + start);
} else if (nlattr->nla_type == CONSOLE_PATH_ATTR) {
// get the console path before setns because it may
// change mnt namespace
config.consolefd = open(data + start, O_RDWR);
if (config.consolefd < 0) {
pr_perror("Failed to open console %s",
data + start);
exit(1);
}
} else if (nlattr->nla_type == NS_PATHS_ATTR) {
// if custom namespaces are required, open all
// descriptors and perform setns on them
int i, j;
int nslen = num_namespaces(data + start);
int fds[nslen];
char *nslist[nslen];
char *ns;
char *saveptr;
for (i = 0; i < nslen; i++) {
char *str = NULL;
if (i == 0) {
str = data + start;
}
ns = strtok_r(str, ",", &saveptr);
if (ns == NULL) {
break;
}
fds[i] = open(ns, O_RDONLY);
if (fds[i] == -1) {
for (j = 0; j < i; j++) {
close(fds[j]);
}
pr_perror("Failed to open %s", ns);
exit(1);
}
nslist[i] = ns;
}
for (i = 0; i < nslen; i++) {
if (setns(fds[i], 0) != 0) {
pr_perror("Failed to setns to %s", nslist[i]);
exit(1);
}
close(fds[i]);
}
} else if (nlattr->nla_type == UIDMAP_ATTR) {
config.uidmap = data + start;
config.uidmap_len = payload_len;
} else if (nlattr->nla_type == GIDMAP_ATTR) {
config.gidmap = data + start;
config.gidmap_len = payload_len;
} else if (nlattr->nla_type == SETGROUP_ATTR) {
config.is_setgroup = readint8(data + start);
} else {
pr_perror("Unknown netlink message type %d",
nlattr->nla_type);
exit(1);
}
start += NLA_ALIGN(payload_len);
}
return config;
}