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libtap: make libtap more thread safe
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Signed-off-by: Fabio M. Di Nitto <fdinitto@redhat.com>
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@fabbione
fabbione committed Dec 18, 2010
1 parent 4a03986 commit 07bc88f
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Showing 2 changed files with 117 additions and 42 deletions.
155 changes: 115 additions & 40 deletions libtap/libtap.c
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Expand Up @@ -145,6 +145,23 @@ STATIC int tap_execute_shell(const char *command)
return err;
}

static int tap_check(const knet_tap_t knet_tap)
{
knet_tap_t temp = tap_cfg.tap_head;

if (!knet_tap)
return 0;

while (temp != NULL) {
if (knet_tap == temp)
return 1;

temp = temp->next;
}

return 0;
}

static void tap_close_unsafe(knet_tap_t knet_tap)
{
if (!knet_tap)
Expand All @@ -169,19 +186,13 @@ static int tap_get_mtu_unsafe(const knet_tap_t knet_tap)
{
int err;

if (!knet_tap) {
errno = EINVAL;
err = -1;
goto out;
}

err = ioctl(tap_cfg.tap_sockfd, SIOCGIFMTU, &knet_tap->ifr);
if (err)
goto out;
goto out_clean;

err = knet_tap->ifr.ifr_mtu;

out:
out_clean:
return err;
}

Expand All @@ -190,23 +201,17 @@ static int tap_get_mac_unsafe(const knet_tap_t knet_tap, char **ether_addr)
int err;
char mac[MAX_MAC_CHAR];

if ((!knet_tap) || (!ether_addr)) {
errno = EINVAL;
err = -1;
goto out;
}

err = ioctl(tap_cfg.tap_sockfd, SIOCGIFHWADDR, &knet_tap->ifr);
if (err)
goto out;
goto out_clean;

ether_ntoa_r((struct ether_addr *)knet_tap->ifr.ifr_hwaddr.sa_data, mac);

*ether_addr = strdup(mac);
if (!*ether_addr)
err = -1;

out:
out_clean:

return err;
}
Expand Down Expand Up @@ -321,16 +326,20 @@ knet_tap_t knet_tap_open(char *dev, size_t dev_size)
return NULL;
}

void knet_tap_close(knet_tap_t knet_tap)
int knet_tap_close(knet_tap_t knet_tap)
{
int err = 0;
knet_tap_t temp = tap_cfg.tap_head;
knet_tap_t prev = tap_cfg.tap_head;

if (!knet_tap)
return;

pthread_mutex_lock(&tap_mutex);

if (!tap_check(knet_tap)) {
errno = EINVAL;
err = -1;
goto out_clean;
}

while ((temp) && (temp != knet_tap)) {
prev = temp;
temp = temp->next;
Expand All @@ -347,9 +356,10 @@ void knet_tap_close(knet_tap_t knet_tap)

tap_close_cfg();

out_clean:
pthread_mutex_unlock(&tap_mutex);

return;
return err;
}

int knet_tap_get_mtu(const knet_tap_t knet_tap)
Expand All @@ -358,8 +368,15 @@ int knet_tap_get_mtu(const knet_tap_t knet_tap)

pthread_mutex_lock(&tap_mutex);

if (!tap_check(knet_tap)) {
errno = EINVAL;
err = -1;
goto out_clean;
}

err = tap_get_mtu_unsafe(knet_tap);

out_clean:
pthread_mutex_unlock(&tap_mutex);

return err;
Expand All @@ -371,10 +388,10 @@ int knet_tap_set_mtu(knet_tap_t knet_tap, const int mtu)

pthread_mutex_lock(&tap_mutex);

if (!knet_tap) {
if (!tap_check(knet_tap)) {
errno = EINVAL;
err = -1;
goto out;
goto out_clean;
}

oldmtu = knet_tap->ifr.ifr_mtu;
Expand All @@ -384,7 +401,7 @@ int knet_tap_set_mtu(knet_tap_t knet_tap, const int mtu)
if (err)
knet_tap->ifr.ifr_mtu = oldmtu;

out:
out_clean:
pthread_mutex_unlock(&tap_mutex);

return err;
Expand All @@ -401,8 +418,15 @@ int knet_tap_get_mac(const knet_tap_t knet_tap, char **ether_addr)

pthread_mutex_lock(&tap_mutex);

if ((!tap_check(knet_tap)) || (!ether_addr)) {
errno = EINVAL;
err = -1;
goto out_clean;
}

err = tap_get_mac_unsafe(knet_tap, ether_addr);

out_clean:
pthread_mutex_unlock(&tap_mutex);

return err;
Expand All @@ -415,10 +439,10 @@ int knet_tap_set_mac(knet_tap_t knet_tap, const char *ether_addr)

pthread_mutex_lock(&tap_mutex);

if ((!knet_tap) || (!ether_addr)) {
if ((!tap_check(knet_tap)) || (!ether_addr)) {
errno = EINVAL;
err = -1;
goto out;
goto out_clean;
}

memcpy(&oldmac, knet_tap->ifr.ifr_hwaddr.sa_data, ETH_ALEN);
Expand All @@ -428,7 +452,7 @@ int knet_tap_set_mac(knet_tap_t knet_tap, const char *ether_addr)
if (err)
memcpy(knet_tap->ifr.ifr_hwaddr.sa_data, &oldmac, ETH_ALEN);

out:
out_clean:
pthread_mutex_unlock(&tap_mutex);

return err;
Expand All @@ -446,10 +470,10 @@ int knet_tap_set_up(knet_tap_t knet_tap)

pthread_mutex_lock(&tap_mutex);

if (!knet_tap) {
if (!tap_check(knet_tap)) {
errno = EINVAL;
err = -1;
goto out;
goto out_clean;
}

oldflags = knet_tap->ifr.ifr_flags;
Expand All @@ -459,7 +483,7 @@ int knet_tap_set_up(knet_tap_t knet_tap)
if (err)
knet_tap->ifr.ifr_flags = oldflags;

out:
out_clean:
pthread_mutex_unlock(&tap_mutex);

return err;
Expand All @@ -472,10 +496,10 @@ int knet_tap_set_down(knet_tap_t knet_tap)

pthread_mutex_lock(&tap_mutex);

if (!knet_tap) {
if (!tap_check(knet_tap)) {
errno = EINVAL;
err = -1;
goto out;
goto out_clean;
}

oldflags = knet_tap->ifr.ifr_flags;
Expand All @@ -485,7 +509,7 @@ int knet_tap_set_down(knet_tap_t knet_tap)
if (err)
knet_tap->ifr.ifr_flags = oldflags;

out:
out_clean:
pthread_mutex_unlock(&tap_mutex);

return err;
Expand Down Expand Up @@ -520,11 +544,6 @@ static int tap_set_ip(knet_tap_t knet_tap, const char *command,
char *broadcast = NULL;
char cmdline[4096];

if ((!knet_tap) || (!ip_addr) || (!prefix) || (!command)) {
errno = EINVAL;
return -1;
}

if (!strchr(ip_addr, ':')) {
broadcast = tap_get_v4_broadcast(ip_addr, prefix);
if (!broadcast) {
Expand Down Expand Up @@ -584,6 +603,12 @@ int knet_tap_add_ip(knet_tap_t knet_tap, const char *ip_addr, const char *prefix

pthread_mutex_lock(&tap_mutex);

if ((!tap_check(knet_tap)) || (!ip_addr) || (!prefix)) {
errno = EINVAL;
err = -1;
goto out_clean;
}

found = tap_find_ip(knet_tap, ip_addr, prefix, &tap_ip, &tap_ip_prev);
if (found)
goto out_clean;
Expand Down Expand Up @@ -619,6 +644,12 @@ int knet_tap_del_ip(knet_tap_t knet_tap, const char *ip_addr, const char *prefix

pthread_mutex_lock(&tap_mutex);

if ((!tap_check(knet_tap)) || (!ip_addr) || (!prefix)) {
errno = EINVAL;
err = -1;
goto out_clean;
}

found = tap_find_ip(knet_tap, ip_addr, prefix, &tap_ip, &tap_ip_prev);
if (!found)
goto out_clean;
Expand All @@ -642,10 +673,54 @@ int knet_tap_del_ip(knet_tap_t knet_tap, const char *ip_addr, const char *prefix

int knet_tap_get_fd(const knet_tap_t knet_tap)
{
return knet_tap->knet_tap_fd;
int fd;

pthread_mutex_lock(&tap_mutex);

if (!tap_check(knet_tap)) {
errno = EINVAL;
fd = -1;
goto out_clean;
}

fd = knet_tap->knet_tap_fd;

out_clean:
pthread_mutex_unlock(&tap_mutex);

return fd;
}

const char *knet_tap_get_name(const knet_tap_t knet_tap)
{
return knet_tap->ifname;
char *name = NULL;

pthread_mutex_lock(&tap_mutex);

if (!tap_check(knet_tap)) {
errno = EINVAL;
goto out_clean;
}

name = knet_tap->ifname;

out_clean:
pthread_mutex_unlock(&tap_mutex);

return name;
}

int knet_tap_get_ips(const knet_tap_t knet_tap, char **ip_addr_list, int **entries)
{
int err = 0;
/*
int found = 0;
char *ip_list = NULL;
struct tap_ip *tap_ip = knet_tap->tap_ip;
*/
pthread_mutex_lock(&tap_mutex);

pthread_mutex_unlock(&tap_mutex);

return err;
}
4 changes: 2 additions & 2 deletions libtap/libtap.h
View file
Expand Up @@ -4,7 +4,7 @@
typedef struct tap_iface *knet_tap_t;

knet_tap_t knet_tap_open(char *dev, size_t dev_size);
void knet_tap_close(knet_tap_t knet_tap);
int knet_tap_close(knet_tap_t knet_tap);

knet_tap_t knet_tap_find(char *dev, size_t dev_size);

Expand All @@ -25,6 +25,6 @@ int knet_tap_set_down(knet_tap_t knet_tap);

int knet_tap_add_ip(knet_tap_t knet_tap, const char *ip_addr, const char *prefix);
int knet_tap_del_ip(knet_tap_t knet_tap, const char *ip_addr, const char *prefix);
// knet_tap_get_ips(const knet_tap_t knet_tap);
int knet_tap_get_ips(const knet_tap_t knet_tap, char **ip_addr_list, int **entries);

#endif

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