ip{6, }tunnel: Avoid copying user-supplied interface name around

In both files' parse_args() functions as well as in iptunnel's do_prl()
and do_6rd() functions, a user-supplied 'dev' parameter is uselessly
copied into a temporary buffer before passing it to ll_name_to_index()
or copying into a struct ifreq.  Avoid this by just caching the argv
pointer value until the later lookup/strcpy.

Signed-off-by: Phil Sutter <phil@nwl.cc>
This commit is contained in:
Phil Sutter 2017-10-02 13:46:35 +02:00 committed by Stephen Hemminger
parent 4c0939a29e
commit 26111ab1db
2 changed files with 12 additions and 16 deletions

View File

@ -136,7 +136,7 @@ static void print_tunnel(struct ip6_tnl_parm2 *p)
static int parse_args(int argc, char **argv, int cmd, struct ip6_tnl_parm2 *p)
{
int count = 0;
char medium[IFNAMSIZ] = {};
const char *medium = NULL;
while (argc > 0) {
if (strcmp(*argv, "mode") == 0) {
@ -180,7 +180,7 @@ static int parse_args(int argc, char **argv, int cmd, struct ip6_tnl_parm2 *p)
memcpy(&p->laddr, &laddr.data, sizeof(p->laddr));
} else if (strcmp(*argv, "dev") == 0) {
NEXT_ARG();
strncpy(medium, *argv, IFNAMSIZ - 1);
medium = *argv;
} else if (strcmp(*argv, "encaplimit") == 0) {
NEXT_ARG();
if (strcmp(*argv, "none") == 0) {
@ -285,7 +285,7 @@ static int parse_args(int argc, char **argv, int cmd, struct ip6_tnl_parm2 *p)
count++;
argc--; argv++;
}
if (medium[0]) {
if (medium) {
p->link = ll_name_to_index(medium);
if (p->link == 0) {
fprintf(stderr, "Cannot find device \"%s\"\n", medium);

View File

@ -60,7 +60,7 @@ static void set_tunnel_proto(struct ip_tunnel_parm *p, int proto)
static int parse_args(int argc, char **argv, int cmd, struct ip_tunnel_parm *p)
{
int count = 0;
char medium[IFNAMSIZ] = {};
const char *medium = NULL;
int isatap = 0;
memset(p, 0, sizeof(*p));
@ -139,7 +139,7 @@ static int parse_args(int argc, char **argv, int cmd, struct ip_tunnel_parm *p)
p->iph.saddr = htonl(INADDR_ANY);
} else if (strcmp(*argv, "dev") == 0) {
NEXT_ARG();
strncpy(medium, *argv, IFNAMSIZ - 1);
medium = *argv;
} else if (strcmp(*argv, "ttl") == 0 ||
strcmp(*argv, "hoplimit") == 0 ||
strcmp(*argv, "hlim") == 0) {
@ -216,7 +216,7 @@ static int parse_args(int argc, char **argv, int cmd, struct ip_tunnel_parm *p)
}
}
if (medium[0]) {
if (medium) {
p->link = ll_name_to_index(medium);
if (p->link == 0) {
fprintf(stderr, "Cannot find device \"%s\"\n", medium);
@ -465,9 +465,8 @@ static int do_prl(int argc, char **argv)
{
struct ip_tunnel_prl p = {};
int count = 0;
int devname = 0;
int cmd = 0;
char medium[IFNAMSIZ] = {};
const char *medium = NULL;
while (argc > 0) {
if (strcmp(*argv, "prl-default") == 0) {
@ -488,8 +487,7 @@ static int do_prl(int argc, char **argv)
count++;
} else if (strcmp(*argv, "dev") == 0) {
NEXT_ARG();
strncpy(medium, *argv, IFNAMSIZ-1);
devname++;
medium = *argv;
} else {
fprintf(stderr,
"Invalid PRL parameter \"%s\"\n", *argv);
@ -502,7 +500,7 @@ static int do_prl(int argc, char **argv)
}
argc--; argv++;
}
if (devname == 0) {
if (!medium) {
fprintf(stderr, "Must specify device\n");
exit(-1);
}
@ -513,9 +511,8 @@ static int do_prl(int argc, char **argv)
static int do_6rd(int argc, char **argv)
{
struct ip_tunnel_6rd ip6rd = {};
int devname = 0;
int cmd = 0;
char medium[IFNAMSIZ] = {};
const char *medium = NULL;
inet_prefix prefix;
while (argc > 0) {
@ -537,8 +534,7 @@ static int do_6rd(int argc, char **argv)
cmd = SIOCDEL6RD;
} else if (strcmp(*argv, "dev") == 0) {
NEXT_ARG();
strncpy(medium, *argv, IFNAMSIZ-1);
devname++;
medium = *argv;
} else {
fprintf(stderr,
"Invalid 6RD parameter \"%s\"\n", *argv);
@ -546,7 +542,7 @@ static int do_6rd(int argc, char **argv)
}
argc--; argv++;
}
if (devname == 0) {
if (!medium) {
fprintf(stderr, "Must specify device\n");
exit(-1);
}