commit 2c060e39201effd50d28a6107135fda9ea2ce908 Author: Yawning Angel yawning@schwanenlied.me Date: Sat Mar 28 15:23:07 2015 +0000

Fix the broken getpeername() implementation.

Signed-off-by: Yawning Angel yawning@schwanenlied.me --- src/lib/getpeername.c | 24 +++++++++--------------- tests/test_getpeername.c | 12 +++++++----- 2 files changed, 16 insertions(+), 20 deletions(-)

diff --git a/src/lib/getpeername.c b/src/lib/getpeername.c index bd93a2b..d8bf701 100644 --- a/src/lib/getpeername.c +++ b/src/lib/getpeername.c @@ -33,6 +33,7 @@ LIBC_GETPEERNAME_RET_TYPE tsocks_getpeername(LIBC_GETPEERNAME_SIG) { int ret = 0; struct connection *conn; + socklen_t sz = 0;

DBG("[getpeername] Requesting address on socket %d", sockfd);

@@ -51,19 +52,9 @@ LIBC_GETPEERNAME_RET_TYPE tsocks_getpeername(LIBC_GETPEERNAME_SIG) }

/* - * Extra check for addrlen since we are about to copy the connection - * content into the given address. - */ - if (*addrlen > sizeof(struct sockaddr)) { - /* Ref to the manpage for the returned value here. */ - errno = EINVAL; - ret = -1; - goto end; - } - - /* - * Copy connected destination address into the given addr with only the - * given len so we don't overflow on purpose. + * Copy the minimum of *addrlen and the size of the actual address + * into the given addr. There are applications that pass in buffers + * that are rather large, which is acceptable behavior. */ switch (conn->dest_addr.domain) { case CONNECTION_DOMAIN_NAME: @@ -73,16 +64,19 @@ LIBC_GETPEERNAME_RET_TYPE tsocks_getpeername(LIBC_GETPEERNAME_SIG) * that has been returned to the application. */ case CONNECTION_DOMAIN_INET: + sz = min(sizeof(conn->dest_addr.u.sin), *addrlen); memcpy(addr, (const struct sockaddr *) &conn->dest_addr.u.sin, - *addrlen); + sz); break; case CONNECTION_DOMAIN_INET6: + sz = min(sizeof(conn->dest_addr.u.sin6), *addrlen); memcpy(addr, (const struct sockaddr *) &conn->dest_addr.u.sin6, - *addrlen); + sz); break; }

/* Success. */ + *addrlen = sz; errno = 0; ret = 0;

diff --git a/tests/test_getpeername.c b/tests/test_getpeername.c index 516596e..df464d2 100644 --- a/tests/test_getpeername.c +++ b/tests/test_getpeername.c @@ -32,6 +32,7 @@ static void test_getpeername(void) char buf[INET_ADDRSTRLEN]; struct sockaddr addr; struct sockaddr_in addrv4; + struct sockaddr_storage ss; socklen_t addrlen; const char *ip = "93.95.227.222";

@@ -68,11 +69,7 @@ static void test_getpeername(void) goto error; }

- /* Very large addrlen. */ - addrlen = -1; - ret = getpeername(inet_sock, &addr, &addrlen); - ok(ret == -1 && errno == EINVAL, "Invalid addrlen"); - + /* Invalid arguments */ addrlen = sizeof(addr); ret = getpeername(inet_sock, NULL, &addrlen); ok(ret == -1 && errno == EFAULT, "Invalid addr ptr"); @@ -90,6 +87,11 @@ static void test_getpeername(void) ok(ret == 0 && strncmp(buf, ip, strlen(ip)) == 0, "Valid returned IP address from getpeername()");

+ /* Large but valid addrlen. */ + addrlen = sizeof(ss); + ret = getpeername(inet_sock, (struct sockaddr *)&ss, &addrlen); + ok(ret == 0 && addrlen == sizeof(addrv4), "Valid returned IP address from getpeername(), large addrlen"); + error: if (inet_sock >= 0) { close(inet_sock);