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bgpd: use safe functions to work with ecom attrs
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Tons of insane just-so pointer math here where it is not needed. This is
too smart. Use safer methods.

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>
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@qlyoung
qlyoung committed Nov 22, 2019
1 parent 21c64e0 commit 91085f9
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Showing 2 changed files with 103 additions and 118 deletions.
219 changes: 103 additions & 116 deletions bgpd/bgp_ecommunity.c
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Expand Up @@ -77,37 +77,36 @@ static void ecommunity_hash_free(struct ecommunity *ecom)
else return 0. */
int ecommunity_add_val(struct ecommunity *ecom, struct ecommunity_val *eval)
{
uint8_t *p;
int ret;
int c;

/* When this is fist value, just add it. */
/* When this is fist value, just add it. */
if (ecom->val == NULL) {
ecom->size++;
ecom->val = XMALLOC(MTYPE_ECOMMUNITY_VAL, ecom_length(ecom));
ecom->size = 1;
ecom->val = XCALLOC(MTYPE_ECOMMUNITY_VAL, ECOMMUNITY_SIZE);
memcpy(ecom->val, eval->val, ECOMMUNITY_SIZE);
return 1;
}

/* If the value already exists in the structure return 0. */
c = 0;
for (p = ecom->val; c < ecom->size; p += ECOMMUNITY_SIZE, c++) {
ret = memcmp(p, eval->val, ECOMMUNITY_SIZE);
for (uint8_t *p = ecom->val; c < ecom->size;
p += ECOMMUNITY_SIZE, c++) {
int ret = memcmp(p, eval->val, ECOMMUNITY_SIZE);
if (ret == 0)
return 0;
if (ret > 0)
else if (ret > 0)
break;
}

/* Add the value to the structure with numerical sorting. */
ecom->size++;
ecom->val =
XREALLOC(MTYPE_ECOMMUNITY_VAL, ecom->val, ecom_length(ecom));
ecom->val = XREALLOC(MTYPE_ECOMMUNITY_VAL, ecom->val,
ecom->size * ECOMMUNITY_SIZE);

memmove(ecom->val + (c + 1) * ECOMMUNITY_SIZE,
ecom->val + c * ECOMMUNITY_SIZE,
memmove(ecom->val + ((c + 1) * ECOMMUNITY_SIZE),
ecom->val + (c * ECOMMUNITY_SIZE),
(ecom->size - 1 - c) * ECOMMUNITY_SIZE);
memcpy(ecom->val + c * ECOMMUNITY_SIZE, eval->val, ECOMMUNITY_SIZE);
memcpy(ecom->val + (c * ECOMMUNITY_SIZE), eval->val, ECOMMUNITY_SIZE);

return 1;
}
Expand Down Expand Up @@ -556,8 +555,8 @@ struct ecommunity *ecommunity_str2com(const char *str, int type,
return ecom;
}

static int ecommunity_rt_soo_str(char *buf, uint8_t *pnt, int type,
int sub_type, int format)
static int ecommunity_rt_soo_str(char *buf, size_t bufsz, uint8_t *pnt,
int type, int sub_type, int format)
{
int len = 0;
const char *prefix;
Expand Down Expand Up @@ -589,23 +588,25 @@ static int ecommunity_rt_soo_str(char *buf, uint8_t *pnt, int type,
eas.val = (*pnt++ << 8);
eas.val |= (*pnt++);

len = sprintf(buf, "%s%u:%u", prefix, eas.as, eas.val);
len = snprintf(buf, bufsz, "%s%u:%u", prefix, eas.as, eas.val);
} else if (type == ECOMMUNITY_ENCODE_AS) {
eas.as = (*pnt++ << 8);
eas.as |= (*pnt++);
pnt = ptr_get_be32(pnt, &eas.val);

len = sprintf(buf, "%s%u:%u", prefix, eas.as, eas.val);
len = snprintf(buf, bufsz, "%s%u:%u", prefix, eas.as, eas.val);
} else if (type == ECOMMUNITY_ENCODE_IP) {
memcpy(&eip.ip, pnt, 4);
pnt += 4;
eip.val = (*pnt++ << 8);
eip.val |= (*pnt++);

len = sprintf(buf, "%s%s:%u", prefix, inet_ntoa(eip.ip),
eip.val);
len = snprintf(buf, bufsz, "%s%s:%u", prefix, inet_ntoa(eip.ip),
eip.val);
}
(void)pnt; /* consume value */

/* consume value */
(void)pnt;

return len;
}
Expand Down Expand Up @@ -640,44 +641,31 @@ char *ecommunity_ecom2str(struct ecommunity *ecom, int format, int filter)
uint8_t *pnt;
uint8_t type = 0;
uint8_t sub_type = 0;
#define ECOMMUNITY_STR_DEFAULT_LEN 64
#define ECOMMUNITY_STRLEN 64
int str_size;
int str_pnt;
char *str_buf;
int len = 0;
int first = 1;

if (ecom->size == 0) {
str_buf = XMALLOC(MTYPE_ECOMMUNITY_STR, 1);
str_buf[0] = '\0';
return str_buf;
}
if (ecom->size == 0)
return XCALLOC(MTYPE_ECOMMUNITY_STR, 1);

/* Prepare buffer. */
str_buf = XMALLOC(MTYPE_ECOMMUNITY_STR, ECOMMUNITY_STR_DEFAULT_LEN + 1);
str_size = ECOMMUNITY_STR_DEFAULT_LEN + 1;
str_buf[0] = '\0';
str_pnt = 0;
/* ecom strlen + space + null term */
str_size = (ecom->size * (ECOMMUNITY_STRLEN + 1)) + 1;
str_buf = XCALLOC(MTYPE_ECOMMUNITY_STR, str_size);

char encbuf[128];

for (i = 0; i < ecom->size; i++) {
int unk_ecom = 0;

/* Make it sure size is enough. */
while (str_pnt + ECOMMUNITY_STR_DEFAULT_LEN >= str_size) {
str_size *= 2;
str_buf = XREALLOC(MTYPE_ECOMMUNITY_STR, str_buf,
str_size);
}
memset(encbuf, 0x00, sizeof(encbuf));

/* Space between each value. */
if (!first) {
str_buf[str_pnt++] = ' ';
len++;
}
if (i > 0)
strlcat(str_buf, " ", str_size);

/* Retrieve value field */
pnt = ecom->val + (i * 8);

/* High-order octet of type. */
/* High-order octet is the type */
type = *pnt++;

if (type == ECOMMUNITY_ENCODE_AS || type == ECOMMUNITY_ENCODE_IP
Expand All @@ -696,135 +684,134 @@ char *ecommunity_ecom2str(struct ecommunity *ecom, int format, int filter)
inet_ntop(AF_INET, ipv4,
ipv4str,
INET_ADDRSTRLEN);
len = sprintf(str_buf + str_pnt,
"NH:%s:%d",
ipv4str, pnt[5]);
snprintf(encbuf, sizeof(encbuf),
"NH:%s:%d", ipv4str, pnt[5]);
} else
unk_ecom = 1;
} else
len = ecommunity_rt_soo_str(str_buf + str_pnt,
pnt, type, sub_type,
format);
} else {
ecommunity_rt_soo_str(encbuf, sizeof(encbuf),
pnt, type, sub_type,
format);
}
} else if (type == ECOMMUNITY_ENCODE_OPAQUE) {
if (filter == ECOMMUNITY_ROUTE_TARGET)
continue;
if (*pnt == ECOMMUNITY_OPAQUE_SUBTYPE_ENCAP) {
uint16_t tunneltype;
memcpy(&tunneltype, pnt + 5, 2);
tunneltype = ntohs(tunneltype);
len = sprintf(str_buf + str_pnt, "ET:%d",
tunneltype);

snprintf(encbuf, sizeof(encbuf), "ET:%d",
tunneltype);
} else if (*pnt == ECOMMUNITY_EVPN_SUBTYPE_DEF_GW) {
len = sprintf(str_buf + str_pnt,
"Default Gateway");
} else
strlcpy(encbuf, "Default Gateway",
sizeof(encbuf));
} else {
unk_ecom = 1;
}
} else if (type == ECOMMUNITY_ENCODE_EVPN) {
if (filter == ECOMMUNITY_ROUTE_TARGET)
continue;
if (*pnt == ECOMMUNITY_EVPN_SUBTYPE_ROUTERMAC) {
struct ethaddr rmac;
pnt++;
memcpy(&rmac, pnt, ETH_ALEN);
len = sprintf(
str_buf + str_pnt,
"Rmac:%02x:%02x:%02x:%02x:%02x:%02x",
(uint8_t)rmac.octet[0],
(uint8_t)rmac.octet[1],
(uint8_t)rmac.octet[2],
(uint8_t)rmac.octet[3],
(uint8_t)rmac.octet[4],
(uint8_t)rmac.octet[5]);

snprintf(encbuf, sizeof(encbuf),
"Rmac:%02x:%02x:%02x:%02x:%02x:%02x",
(uint8_t)rmac.octet[0],
(uint8_t)rmac.octet[1],
(uint8_t)rmac.octet[2],
(uint8_t)rmac.octet[3],
(uint8_t)rmac.octet[4],
(uint8_t)rmac.octet[5]);
} else if (*pnt
== ECOMMUNITY_EVPN_SUBTYPE_MACMOBILITY) {
uint32_t seqnum;
uint8_t flags = *++pnt;

memcpy(&seqnum, pnt + 2, 4);
seqnum = ntohl(seqnum);
if (flags
& ECOMMUNITY_EVPN_SUBTYPE_MACMOBILITY_FLAG_STICKY)
len = sprintf(str_buf + str_pnt,
"MM:%u, sticky MAC",
seqnum);
else
len = sprintf(str_buf + str_pnt,
"MM:%u", seqnum);

snprintf(encbuf, sizeof(encbuf), "MM:%u",
seqnum);

if (CHECK_FLAG(
flags,
ECOMMUNITY_EVPN_SUBTYPE_MACMOBILITY_FLAG_STICKY))
strlcat(encbuf, ", sticky MAC",
sizeof(encbuf));
} else if (*pnt == ECOMMUNITY_EVPN_SUBTYPE_ND) {
uint8_t flags = *++pnt;

if (flags
& ECOMMUNITY_EVPN_SUBTYPE_ND_ROUTER_FLAG)
len = sprintf(str_buf + str_pnt,
"ND:Router Flag");
if (CHECK_FLAG(
flags,
ECOMMUNITY_EVPN_SUBTYPE_ND_ROUTER_FLAG))
strlcpy(encbuf, "ND:Router Flag",
sizeof(encbuf));
} else
unk_ecom = 1;
} else if (type == ECOMMUNITY_ENCODE_REDIRECT_IP_NH) {
sub_type = *pnt++;
if (sub_type == ECOMMUNITY_REDIRECT_IP_NH) {
len = sprintf(
str_buf + str_pnt,
"FS:redirect IP 0x%x", *(pnt+5));
snprintf(encbuf, sizeof(encbuf),
"FS:redirect IP 0x%x", *(pnt + 5));
} else
unk_ecom = 1;
} else if (type == ECOMMUNITY_ENCODE_TRANS_EXP ||
type == ECOMMUNITY_EXTENDED_COMMUNITY_PART_2 ||
type == ECOMMUNITY_EXTENDED_COMMUNITY_PART_3) {
sub_type = *pnt++;
if (sub_type == ECOMMUNITY_REDIRECT_VRF) {
char buf[16];

memset(buf, 0, sizeof(buf));
ecommunity_rt_soo_str(buf, (uint8_t *)pnt,
type &
~ECOMMUNITY_ENCODE_TRANS_EXP,
ECOMMUNITY_ROUTE_TARGET,
ECOMMUNITY_FORMAT_DISPLAY);
len = snprintf(str_buf + str_pnt,
str_size - len,
"FS:redirect VRF %s", buf);
char buf[16] = {};
ecommunity_rt_soo_str(
buf, sizeof(buf), (uint8_t *)pnt,
type & ~ECOMMUNITY_ENCODE_TRANS_EXP,
ECOMMUNITY_ROUTE_TARGET,
ECOMMUNITY_FORMAT_DISPLAY);
snprintf(encbuf, sizeof(encbuf),
"FS:redirect VRF %s", buf);
} else if (type != ECOMMUNITY_ENCODE_TRANS_EXP)
unk_ecom = 1;
else if (sub_type == ECOMMUNITY_TRAFFIC_ACTION) {
char action[64];
char *ptr = action;

if (*(pnt+3) ==
1 << FLOWSPEC_TRAFFIC_ACTION_TERMINAL)
ptr += snprintf(ptr, sizeof(action),
"terminate (apply)");
strlcpy(action, "terminate (apply)",
sizeof(action));
else
ptr += snprintf(ptr, sizeof(action),
"eval stops");
strlcpy(action, "eval stops",
sizeof(action));

if (*(pnt+3) ==
1 << FLOWSPEC_TRAFFIC_ACTION_SAMPLE)
snprintf(ptr, sizeof(action) -
(size_t)(ptr-action),
", sample");
len = snprintf(str_buf + str_pnt,
str_size - len,
"FS:action %s", action);
strlcat(action, ", sample",
sizeof(action));


snprintf(encbuf, sizeof(encbuf), "FS:action %s",
action);
} else if (sub_type == ECOMMUNITY_TRAFFIC_RATE) {
union traffic_rate data;

data.rate_byte[3] = *(pnt+2);
data.rate_byte[2] = *(pnt+3);
data.rate_byte[1] = *(pnt+4);
data.rate_byte[0] = *(pnt+5);
len = sprintf(
str_buf + str_pnt,
"FS:rate %f", data.rate_float);
snprintf(encbuf, sizeof(encbuf), "FS:rate %f",
data.rate_float);
} else if (sub_type == ECOMMUNITY_TRAFFIC_MARKING) {
len = sprintf(
str_buf + str_pnt,
"FS:marking %u", *(pnt+5));
snprintf(encbuf, sizeof(encbuf),
"FS:marking %u", *(pnt + 5));
} else if (*pnt
== ECOMMUNITY_EVPN_SUBTYPE_ES_IMPORT_RT) {
struct ethaddr mac;

memcpy(&mac, pnt, ETH_ALEN);
len = sprintf(
str_buf + str_pnt,

snprintf(
encbuf, sizeof(encbuf),
"ES-Import-Rt:%02x:%02x:%02x:%02x:%02x:%02x",
(uint8_t)mac.octet[0],
(uint8_t)mac.octet[1],
Expand All @@ -840,11 +827,11 @@ char *ecommunity_ecom2str(struct ecommunity *ecom, int format, int filter)
}

if (unk_ecom)
len = sprintf(str_buf + str_pnt, "UNK:%d, %d",
type, sub_type);
snprintf(encbuf, sizeof(encbuf), "UNK:%d, %d", type,
sub_type);

str_pnt += len;
first = 0;
int r = strlcat(str_buf, encbuf, str_size);
assert(r < str_size);
}

return str_buf;
Expand Down
2 changes: 0 additions & 2 deletions bgpd/bgp_ecommunity.h
View file
Expand Up @@ -105,8 +105,6 @@ struct ecommunity_val {
char val[ECOMMUNITY_SIZE];
};

#define ecom_length(X) ((X)->size * ECOMMUNITY_SIZE)

/*
* Encode BGP Route Target AS:nn.
*/
Expand Down

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