net: sctp: check proc_dointvec result in proc_sctp_do_auth

[pandora-kernel.git] / net / sctp / sysctl.c

diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c
index 7e5eb75..12c7e01 100644 (file)
--- a/net/sctp/sysctl.c
+++ b/net/sctp/sysctl.c
@@ -34,6 +34,8 @@
  *    Sridhar Samudrala     <sri@us.ibm.com>
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <net/sctp/structs.h>
 #include <net/sctp/sctp.h>
 #include <linux/sysctl.h>
@@ -46,6 +48,11 @@ static int sack_timer_min = 1;
 static int sack_timer_max = 500;
 static int addr_scope_max = 3; /* check sctp_scope_policy_t in include/net/sctp/constants.h for max entries */
 static int rwnd_scale_max = 16;
+static int rto_alpha_min = 0;
+static int rto_beta_min = 0;
+static int rto_alpha_max = 1000;
+static int rto_beta_max = 1000;
+
 static unsigned long max_autoclose_min = 0;
 static unsigned long max_autoclose_max =
        (MAX_SCHEDULE_TIMEOUT / HZ > UINT_MAX)
@@ -64,6 +71,9 @@ static int proc_sctp_do_rto_min(struct ctl_table *ctl, int write,
 static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write,
                                void __user *buffer, size_t *lenp,
                                loff_t *ppos);
+static int proc_sctp_do_alpha_beta(struct ctl_table *ctl, int write,
+                                  void __user *buffer, size_t *lenp,
+                                  loff_t *ppos);
 static int proc_sctp_do_auth(struct ctl_table *ctl, int write,
                             void __user *buffer, size_t *lenp,
                             loff_t *ppos);
@@ -126,15 +136,19 @@ static struct ctl_table sctp_net_table[] = {
                .procname       = "rto_alpha_exp_divisor",
                .data           = &init_net.sctp.rto_alpha,
                .maxlen         = sizeof(int),
-               .mode           = 0444,
-               .proc_handler   = proc_dointvec,
+               .mode           = 0644,
+               .proc_handler   = proc_sctp_do_alpha_beta,
+               .extra1         = &rto_alpha_min,
+               .extra2         = &rto_alpha_max,
        },
        {
                .procname       = "rto_beta_exp_divisor",
                .data           = &init_net.sctp.rto_beta,
                .maxlen         = sizeof(int),
-               .mode           = 0444,
-               .proc_handler   = proc_dointvec,
+               .mode           = 0644,
+               .proc_handler   = proc_sctp_do_alpha_beta,
+               .extra1         = &rto_beta_min,
+               .extra2         = &rto_beta_max,
        },
        {
                .procname       = "max_burst",
@@ -307,41 +321,40 @@ static int proc_sctp_do_hmac_alg(struct ctl_table *ctl, int write,
                                loff_t *ppos)
 {
        struct net *net = current->nsproxy->net_ns;
-       char tmp[8];
        struct ctl_table tbl;
-       int ret;
-       int changed = 0;
+       bool changed = false;
        char *none = "none";
+       char tmp[8];
+       int ret;
 
        memset(&tbl, 0, sizeof(struct ctl_table));
 
        if (write) {
                tbl.data = tmp;
-               tbl.maxlen = 8;
+               tbl.maxlen = sizeof(tmp);
        } else {
                tbl.data = net->sctp.sctp_hmac_alg ? : none;
                tbl.maxlen = strlen(tbl.data);
        }
-               ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
 
-       if (write) {
+       ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
+       if (write && ret == 0) {
 #ifdef CONFIG_CRYPTO_MD5
                if (!strncmp(tmp, "md5", 3)) {
                        net->sctp.sctp_hmac_alg = "md5";
-                       changed = 1;
+                       changed = true;
                }
 #endif
 #ifdef CONFIG_CRYPTO_SHA1
                if (!strncmp(tmp, "sha1", 4)) {
                        net->sctp.sctp_hmac_alg = "sha1";
-                       changed = 1;
+                       changed = true;
                }
 #endif
                if (!strncmp(tmp, "none", 4)) {
                        net->sctp.sctp_hmac_alg = NULL;
-                       changed = 1;
+                       changed = true;
                }
-
                if (!changed)
                        ret = -EINVAL;
        }
@@ -354,11 +367,10 @@ static int proc_sctp_do_rto_min(struct ctl_table *ctl, int write,
                                loff_t *ppos)
 {
        struct net *net = current->nsproxy->net_ns;
-       int new_value;
-       struct ctl_table tbl;
        unsigned int min = *(unsigned int *) ctl->extra1;
        unsigned int max = *(unsigned int *) ctl->extra2;
-       int ret;
+       struct ctl_table tbl;
+       int ret, new_value;
 
        memset(&tbl, 0, sizeof(struct ctl_table));
        tbl.maxlen = sizeof(unsigned int);
@@ -367,12 +379,15 @@ static int proc_sctp_do_rto_min(struct ctl_table *ctl, int write,
                tbl.data = &new_value;
        else
                tbl.data = &net->sctp.rto_min;
+
        ret = proc_dointvec(&tbl, write, buffer, lenp, ppos);
-       if (write) {
-               if (ret || new_value > max || new_value < min)
+       if (write && ret == 0) {
+               if (new_value > max || new_value < min)
                        return -EINVAL;
+
                net->sctp.rto_min = new_value;
        }
+
        return ret;
 }
 
@@ -381,11 +396,10 @@ static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write,
                                loff_t *ppos)
 {
        struct net *net = current->nsproxy->net_ns;
-       int new_value;
-       struct ctl_table tbl;
        unsigned int min = *(unsigned int *) ctl->extra1;
        unsigned int max = *(unsigned int *) ctl->extra2;
-       int ret;
+       struct ctl_table tbl;
+       int ret, new_value;
 
        memset(&tbl, 0, sizeof(struct ctl_table));
        tbl.maxlen = sizeof(unsigned int);
@@ -394,15 +408,28 @@ static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write,
                tbl.data = &new_value;
        else
                tbl.data = &net->sctp.rto_max;
+
        ret = proc_dointvec(&tbl, write, buffer, lenp, ppos);
-       if (write) {
-               if (ret || new_value > max || new_value < min)
+       if (write && ret == 0) {
+               if (new_value > max || new_value < min)
                        return -EINVAL;
+
                net->sctp.rto_max = new_value;
        }
+
        return ret;
 }
 
+static int proc_sctp_do_alpha_beta(struct ctl_table *ctl, int write,
+                                  void __user *buffer, size_t *lenp,
+                                  loff_t *ppos)
+{
+       pr_warn_once("Changing rto_alpha or rto_beta may lead to "
+                    "suboptimal rtt/srtt estimations!\n");
+
+       return proc_dointvec_minmax(ctl, write, buffer, lenp, ppos);
+}
+
 static int proc_sctp_do_auth(struct ctl_table *ctl, int write,
                             void __user *buffer, size_t *lenp,
                             loff_t *ppos)
@@ -420,8 +447,7 @@ static int proc_sctp_do_auth(struct ctl_table *ctl, int write,
                tbl.data = &net->sctp.auth_enable;
 
        ret = proc_dointvec(&tbl, write, buffer, lenp, ppos);
-
-       if (write) {
+       if (write && ret == 0) {
                struct sock *sk = net->sctp.ctl_sock;
 
                net->sctp.auth_enable = new_value;