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Message-Id: <20190504164853.4736-1-mcroce@redhat.com>
Date: Sat, 4 May 2019 18:48:53 +0200
From: Matteo Croce <mcroce@...hat.com>
To: linux-ppp@...r.kernel.org, netdev@...r.kernel.org
Cc: Paul Mackerras <paulus@...abs.org>, Jo-Philipp Wich <jo@...n.io>
Subject: [PATCH pppd v4] pppoe: custom host-uniq tag
Add pppoe 'host-uniq' option to set an arbitrary
host-uniq tag instead of the pppd pid.
Some ISPs use such tag to authenticate the CPE,
so it must be set to a proper value to connect.
Signed-off-by: Matteo Croce <mcroce@...hat.com>
Signed-off-by: Jo-Philipp Wich <jo@...n.io>
---
pppd/plugins/rp-pppoe/common.c | 14 +++----
pppd/plugins/rp-pppoe/discovery.c | 52 ++++++++++---------------
pppd/plugins/rp-pppoe/plugin.c | 15 ++++++-
pppd/plugins/rp-pppoe/pppoe-discovery.c | 41 ++++++++++++-------
pppd/plugins/rp-pppoe/pppoe.h | 30 +++++++++++++-
5 files changed, 96 insertions(+), 56 deletions(-)
diff --git a/pppd/plugins/rp-pppoe/common.c b/pppd/plugins/rp-pppoe/common.c
index 89c633c..8f175ec 100644
--- a/pppd/plugins/rp-pppoe/common.c
+++ b/pppd/plugins/rp-pppoe/common.c
@@ -119,15 +119,11 @@ sendPADT(PPPoEConnection *conn, char const *msg)
conn->session = 0;
/* If we're using Host-Uniq, copy it over */
- if (conn->useHostUniq) {
- PPPoETag hostUniq;
- pid_t pid = getpid();
- hostUniq.type = htons(TAG_HOST_UNIQ);
- hostUniq.length = htons(sizeof(pid));
- memcpy(hostUniq.payload, &pid, sizeof(pid));
- memcpy(cursor, &hostUniq, sizeof(pid) + TAG_HDR_SIZE);
- cursor += sizeof(pid) + TAG_HDR_SIZE;
- plen += sizeof(pid) + TAG_HDR_SIZE;
+ if (conn->hostUniq.length) {
+ int len = ntohs(conn->hostUniq.length);
+ memcpy(cursor, &conn->hostUniq, len + TAG_HDR_SIZE);
+ cursor += len + TAG_HDR_SIZE;
+ plen += len + TAG_HDR_SIZE;
}
/* Copy error message */
diff --git a/pppd/plugins/rp-pppoe/discovery.c b/pppd/plugins/rp-pppoe/discovery.c
index 04877cb..16a59f7 100644
--- a/pppd/plugins/rp-pppoe/discovery.c
+++ b/pppd/plugins/rp-pppoe/discovery.c
@@ -80,14 +80,10 @@ static void
parseForHostUniq(UINT16_t type, UINT16_t len, unsigned char *data,
void *extra)
{
- int *val = (int *) extra;
- if (type == TAG_HOST_UNIQ && len == sizeof(pid_t)) {
- pid_t tmp;
- memcpy(&tmp, data, len);
- if (tmp == getpid()) {
- *val = 1;
- }
- }
+ PPPoETag *tag = extra;
+
+ if (type == TAG_HOST_UNIQ && len == ntohs(tag->length))
+ tag->length = memcmp(data, tag->payload, len);
}
/**********************************************************************
@@ -104,16 +100,16 @@ parseForHostUniq(UINT16_t type, UINT16_t len, unsigned char *data,
static int
packetIsForMe(PPPoEConnection *conn, PPPoEPacket *packet)
{
- int forMe = 0;
+ PPPoETag hostUniq = conn->hostUniq;
/* If packet is not directed to our MAC address, forget it */
if (memcmp(packet->ethHdr.h_dest, conn->myEth, ETH_ALEN)) return 0;
/* If we're not using the Host-Unique tag, then accept the packet */
- if (!conn->useHostUniq) return 1;
+ if (!conn->hostUniq.length) return 1;
- parsePacket(packet, parseForHostUniq, &forMe);
- return forMe;
+ parsePacket(packet, parseForHostUniq, &hostUniq);
+ return !hostUniq.length;
}
/**********************************************************************
@@ -301,16 +297,12 @@ sendPADI(PPPoEConnection *conn)
}
/* If we're using Host-Uniq, copy it over */
- if (conn->useHostUniq) {
- PPPoETag hostUniq;
- pid_t pid = getpid();
- hostUniq.type = htons(TAG_HOST_UNIQ);
- hostUniq.length = htons(sizeof(pid));
- memcpy(hostUniq.payload, &pid, sizeof(pid));
- CHECK_ROOM(cursor, packet.payload, sizeof(pid) + TAG_HDR_SIZE);
- memcpy(cursor, &hostUniq, sizeof(pid) + TAG_HDR_SIZE);
- cursor += sizeof(pid) + TAG_HDR_SIZE;
- plen += sizeof(pid) + TAG_HDR_SIZE;
+ if (conn->hostUniq.length) {
+ int len = ntohs(conn->hostUniq.length);
+ CHECK_ROOM(cursor, packet.payload, len + TAG_HDR_SIZE);
+ memcpy(cursor, &conn->hostUniq, len + TAG_HDR_SIZE);
+ cursor += len + TAG_HDR_SIZE;
+ plen += len + TAG_HDR_SIZE;
}
/* Add our maximum MTU/MRU */
@@ -478,16 +470,12 @@ sendPADR(PPPoEConnection *conn)
cursor += namelen + TAG_HDR_SIZE;
/* If we're using Host-Uniq, copy it over */
- if (conn->useHostUniq) {
- PPPoETag hostUniq;
- pid_t pid = getpid();
- hostUniq.type = htons(TAG_HOST_UNIQ);
- hostUniq.length = htons(sizeof(pid));
- memcpy(hostUniq.payload, &pid, sizeof(pid));
- CHECK_ROOM(cursor, packet.payload, sizeof(pid)+TAG_HDR_SIZE);
- memcpy(cursor, &hostUniq, sizeof(pid) + TAG_HDR_SIZE);
- cursor += sizeof(pid) + TAG_HDR_SIZE;
- plen += sizeof(pid) + TAG_HDR_SIZE;
+ if (conn->hostUniq.length) {
+ int len = ntohs(conn->hostUniq.length);
+ CHECK_ROOM(cursor, packet.payload, len+TAG_HDR_SIZE);
+ memcpy(cursor, &conn->hostUniq, len + TAG_HDR_SIZE);
+ cursor += len + TAG_HDR_SIZE;
+ plen += len + TAG_HDR_SIZE;
}
/* Add our maximum MTU/MRU */
diff --git a/pppd/plugins/rp-pppoe/plugin.c b/pppd/plugins/rp-pppoe/plugin.c
index c89be94..966be15 100644
--- a/pppd/plugins/rp-pppoe/plugin.c
+++ b/pppd/plugins/rp-pppoe/plugin.c
@@ -68,6 +68,7 @@ static char *existingSession = NULL;
static int printACNames = 0;
static char *pppoe_reqd_mac = NULL;
unsigned char pppoe_reqd_mac_addr[6];
+static char *host_uniq;
static int PPPoEDevnameHook(char *cmd, char **argv, int doit);
static option_t Options[] = {
@@ -85,6 +86,8 @@ static option_t Options[] = {
"Be verbose about discovered access concentrators"},
{ "pppoe-mac", o_string, &pppoe_reqd_mac,
"Only connect to specified MAC address" },
+ { "host-uniq", o_string, &host_uniq,
+ "Set the Host-Uniq to the supplied hex string" },
{ NULL }
};
int (*OldDevnameHook)(char *cmd, char **argv, int doit) = NULL;
@@ -110,7 +113,6 @@ PPPOEInitDevice(void)
conn->ifName = devnam;
conn->discoverySocket = -1;
conn->sessionSocket = -1;
- conn->useHostUniq = 1;
conn->printACNames = printACNames;
conn->discoveryTimeout = PADI_TIMEOUT;
return 1;
@@ -166,6 +168,17 @@ PPPOEConnectDevice(void)
if (lcp_wantoptions[0].mru > ifr.ifr_mtu - TOTAL_OVERHEAD)
lcp_wantoptions[0].mru = ifr.ifr_mtu - TOTAL_OVERHEAD;
+ if (host_uniq) {
+ if (!parseHostUniq(host_uniq, &conn->hostUniq))
+ fatal("Illegal value for host-uniq option");
+ } else {
+ /* if a custom host-uniq is not supplied, use our PID */
+ pid_t pid = getpid();
+ conn->hostUniq.type = htons(TAG_HOST_UNIQ);
+ conn->hostUniq.length = htons(sizeof(pid));
+ memcpy(conn->hostUniq.payload, &pid, sizeof(pid));
+ }
+
conn->acName = acName;
conn->serviceName = pppd_pppoe_service;
strlcpy(ppp_devnam, devnam, sizeof(ppp_devnam));
diff --git a/pppd/plugins/rp-pppoe/pppoe-discovery.c b/pppd/plugins/rp-pppoe/pppoe-discovery.c
index bce71fc..f71aec8 100644
--- a/pppd/plugins/rp-pppoe/pppoe-discovery.c
+++ b/pppd/plugins/rp-pppoe/pppoe-discovery.c
@@ -356,7 +356,7 @@ packetIsForMe(PPPoEConnection *conn, PPPoEPacket *packet)
if (memcmp(packet->ethHdr.h_dest, conn->myEth, ETH_ALEN)) return 0;
/* If we're not using the Host-Unique tag, then accept the packet */
- if (!conn->useHostUniq) return 1;
+ if (!conn->hostUniq.length) return 1;
parsePacket(packet, parseForHostUniq, &forMe);
return forMe;
@@ -494,16 +494,12 @@ sendPADI(PPPoEConnection *conn)
cursor += namelen + TAG_HDR_SIZE;
/* If we're using Host-Uniq, copy it over */
- if (conn->useHostUniq) {
- PPPoETag hostUniq;
- pid_t pid = getpid();
- hostUniq.type = htons(TAG_HOST_UNIQ);
- hostUniq.length = htons(sizeof(pid));
- memcpy(hostUniq.payload, &pid, sizeof(pid));
- CHECK_ROOM(cursor, packet.payload, sizeof(pid) + TAG_HDR_SIZE);
- memcpy(cursor, &hostUniq, sizeof(pid) + TAG_HDR_SIZE);
- cursor += sizeof(pid) + TAG_HDR_SIZE;
- plen += sizeof(pid) + TAG_HDR_SIZE;
+ if (conn->hostUniq.length) {
+ int len = ntohs(conn->hostUniq.length);
+ CHECK_ROOM(cursor, packet.payload, len + TAG_HDR_SIZE);
+ memcpy(cursor, &conn->hostUniq, len + TAG_HDR_SIZE);
+ cursor += len + TAG_HDR_SIZE;
+ plen += len + TAG_HDR_SIZE;
}
packet.length = htons(plen);
@@ -669,7 +665,7 @@ int main(int argc, char *argv[])
conn->discoveryTimeout = PADI_TIMEOUT;
conn->discoveryAttempts = MAX_PADI_ATTEMPTS;
- while ((opt = getopt(argc, argv, "I:D:VUQS:C:t:a:h")) > 0) {
+ while ((opt = getopt(argc, argv, "I:D:VUQS:C:W:t:a:h")) > 0) {
switch(opt) {
case 'S':
conn->serviceName = xstrdup(optarg);
@@ -696,7 +692,25 @@ int main(int argc, char *argv[])
}
break;
case 'U':
- conn->useHostUniq = 1;
+ if(conn->hostUniq.length) {
+ fprintf(stderr, "-U and -W are mutually exclusive\n");
+ exit(EXIT_FAILURE);
+ } else {
+ pid_t pid = getpid();
+ conn->hostUniq.type = htons(TAG_HOST_UNIQ);
+ conn->hostUniq.length = htons(sizeof(pid));
+ memcpy(conn->hostUniq.payload, &pid, sizeof(pid));
+ }
+ break;
+ case 'W':
+ if(conn->hostUniq.length) {
+ fprintf(stderr, "-U and -W are mutually exclusive\n");
+ exit(EXIT_FAILURE);
+ }
+ if (!parseHostUniq(optarg, &conn->hostUniq)) {
+ fprintf(stderr, "Invalid host-uniq argument: %s\n", optarg);
+ exit(EXIT_FAILURE);
+ }
break;
case 'D':
conn->debugFile = fopen(optarg, "w");
@@ -777,6 +791,7 @@ void usage(void)
" -S name -- Set desired service name.\n"
" -C name -- Set desired access concentrator name.\n"
" -U -- Use Host-Unique to allow multiple PPPoE sessions.\n"
+ " -W hexvalue -- Set the Host-Unique to the supplied hex string.\n"
" -h -- Print usage information.\n");
fprintf(stderr, "\nVersion " RP_VERSION "\n");
}
diff --git a/pppd/plugins/rp-pppoe/pppoe.h b/pppd/plugins/rp-pppoe/pppoe.h
index 813dcf3..2ea153f 100644
--- a/pppd/plugins/rp-pppoe/pppoe.h
+++ b/pppd/plugins/rp-pppoe/pppoe.h
@@ -21,6 +21,8 @@
#include <stdio.h> /* For FILE */
#include <sys/types.h> /* For pid_t */
+#include <ctype.h>
+#include <string.h>
/* How do we access raw Ethernet devices? */
#undef USE_LINUX_PACKET
@@ -236,7 +238,7 @@ typedef struct PPPoEConnectionStruct {
char *serviceName; /* Desired service name, if any */
char *acName; /* Desired AC name, if any */
int synchronous; /* Use synchronous PPP */
- int useHostUniq; /* Use Host-Uniq tag */
+ PPPoETag hostUniq; /* Use Host-Uniq tag */
int printACNames; /* Just print AC names */
FILE *debugFile; /* Debug file for dumping packets */
int numPADOs; /* Number of PADO packets received */
@@ -293,6 +295,32 @@ void pppoe_printpkt(PPPoEPacket *packet,
void (*printer)(void *, char *, ...), void *arg);
void pppoe_log_packet(const char *prefix, PPPoEPacket *packet);
+static inline int parseHostUniq(const char *uniq, PPPoETag *tag)
+{
+ unsigned i, len = strlen(uniq);
+
+#define hex(x) \
+ (((x) <= '9') ? ((x) - '0') : \
+ (((x) <= 'F') ? ((x) - 'A' + 10) : \
+ ((x) - 'a' + 10)))
+
+ if (!len || len % 2 || len / 2 > sizeof(tag->payload))
+ return 0;
+
+ for (i = 0; i < len; i += 2) {
+ if (!isxdigit(uniq[i]) || !isxdigit(uniq[i+1]))
+ return 0;
+
+ tag->payload[i / 2] = (char)(hex(uniq[i]) << 4 | hex(uniq[i+1]));
+ }
+
+#undef hex
+
+ tag->type = htons(TAG_HOST_UNIQ);
+ tag->length = htons(len / 2);
+ return 1;
+}
+
#define SET_STRING(var, val) do { if (var) free(var); var = strDup(val); } while(0);
#define CHECK_ROOM(cursor, start, len) \
--
2.21.0
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