From 5677aedfb8ca568a5f679035153cca9ef87b2a22 Mon Sep 17 00:00:00 2001 From: John Hodge Date: Fri, 18 May 2012 17:26:04 +0800 Subject: [PATCH] Usermode/DHCPC - Bugfixing and implementing select() timeouts --- Usermode/Applications/dhcpclient_src/main.c | 148 +++++++++++++++--- .../ld-acess.so_src/arch/syscalls.s.h | 1 + Usermode/Libraries/ld-acess.so_src/export.c | 2 + Usermode/include/acess/sys.h | 1 + 4 files changed, 128 insertions(+), 24 deletions(-) diff --git a/Usermode/Applications/dhcpclient_src/main.c b/Usermode/Applications/dhcpclient_src/main.c index 7c0b0726..72957885 100644 --- a/Usermode/Applications/dhcpclient_src/main.c +++ b/Usermode/Applications/dhcpclient_src/main.c @@ -1,4 +1,6 @@ /* + * + * http://www.ietf.org/rfc/rfc2131.txt */ #include #include @@ -63,6 +65,11 @@ typedef struct sInterface int Num; int SocketFD; int IfaceFD; + + uint32_t TransactionID; + char HWAddr[6]; + + int64_t Timeout; } tInterface; // === PROTOTYPES === @@ -72,6 +79,8 @@ int Start_Interface(tInterface *Iface); void Send_DHCPDISCOVER(tInterface *Iface); void Send_DHCPREQUEST(tInterface *Iface, void *OfferBuffer, int TypeOffset); int Handle_Packet(tInterface *Iface); +void Handle_Timeout(tInterface *Iface); +void Update_State(tInterface *Iface, int newState); void SetAddress(tInterface *Iface, void *Addr, void *Mask, void *Router); // === CODE === @@ -96,10 +105,10 @@ int main(int argc, char *argv[]) for( i = ifaces; i; i = i->Next ) { - i->State = STATE_PREINIT; if( Start_Interface(i) < 0 ) { return -1; } + i->State = STATE_PREINIT; // Send request Send_DHCPDISCOVER(i); @@ -110,6 +119,7 @@ int main(int argc, char *argv[]) int maxfd; fd_set fds; tInterface *p; + int64_t timeout = 1000; maxfd = 0; FD_ZERO(&fds); @@ -118,12 +128,15 @@ int main(int argc, char *argv[]) FD_SET(i->SocketFD, &fds); if(maxfd < i->SocketFD) maxfd = i->SocketFD; } - if( select(maxfd+1, &fds, NULL, NULL, NULL) < 0 ) + + if( select(maxfd+1, &fds, NULL, NULL, &timeout) < 0 ) { // TODO: Check error result return -1; } + _SysDebug("select() returned"); + // Check for changes (with magic to allow inline deletion) for( p = (void*)&ifaces, i = ifaces; i; p=i,i = i->Next ) { @@ -138,6 +151,11 @@ int main(int argc, char *argv[]) i = p; } } + + if( _SysTimestamp() > i->Timeout ) + { + Handle_Timeout(i); + } } } return 0; @@ -175,6 +193,20 @@ int Start_Interface(tInterface *Iface) // TODO: Check that the adapter is not in use + // Request MAC address from network adapter + { + char path[] = "/Devices/ip/adapters/ethXXXX"; + sprintf(path, "/Devices/ip/adapters/%s", Iface->Adapter); + fd = open(path, 0); + if(fd == -1) { + _SysDebug("Unable to open adapter %s", path); + return -1; + } + ioctl(fd, 4, Iface->HWAddr); + // TODO: Check if ioctl() failed + close(fd); + } + // Initialise an interface, with a dummy IP address (zero) fd = open("/Devices/ip", 0); if( fd == -1 ) { @@ -215,6 +247,10 @@ int Start_Interface(tInterface *Iface) return 0; } +void Send_DHCPRELEASE(tInterface *Iface) +{ +} + void Send_DHCPDISCOVER(tInterface *Iface) { uint32_t transaction_id; @@ -222,7 +258,10 @@ void Send_DHCPDISCOVER(tInterface *Iface) char data[8 + sizeof(struct sDHCP_Message) + 3 + 1]; msg = (void*)data + 8; + _SysDebug("DHCPDISCOVER to %s", Iface->Adapter); + transaction_id = rand(); + Iface->TransactionID = transaction_id; msg->op = htonb(1); // BOOTREQUEST msg->htype = htonb(1); // 10mb Ethernet @@ -230,25 +269,13 @@ void Send_DHCPDISCOVER(tInterface *Iface) msg->hops = htonb(0); // Hop count so far msg->xid = htonl(transaction_id); // Transaction ID msg->secs = htons(0); // secs - No time has elapsed - msg->flags = htons(0); // flags - TODO: Check if broadcast bit need be set + msg->flags = htons(0x0000); // flags - Broadcast is unset msg->ciaddr = htonl(0); // ciaddr - Zero, as we don't have one yet msg->yiaddr = htonl(0); // yiaddr - Zero? msg->siaddr = htonl(0); // siaddr - Zero? maybe -1 msg->giaddr = htonl(0); // giaddr - Zero? - // Request MAC address from network adapter - { - char path[] = "/Devices/ip/adapters/ethXXXX"; - sprintf(path, "/Devices/ip/adapters/%s", Iface->Adapter); - int fd = open(path, 0); - if(fd == -1) { - _SysDebug("Unable to open adapter %s", path); - } - else { - ioctl(fd, 4, msg->chaddr); - // TODO: Check if ioctl() failed - close(fd); - } - } + memcpy(msg->chaddr, Iface->HWAddr, 6); + memset(msg->sname, 0, sizeof(msg->sname)); // Nuke the rest memset(msg->file, 0, sizeof(msg->file)); // Nuke the rest msg->dhcp_magic = htonl(DHCP_MAGIC); @@ -265,21 +292,53 @@ void Send_DHCPDISCOVER(tInterface *Iface) data[4] = 255; data[5] = 255; data[6] = 255; data[7] = 255; write(Iface->SocketFD, data, sizeof(data)); - Iface->State = STATE_DISCOVER_SENT; + Update_State(Iface, STATE_DISCOVER_SENT); } void Send_DHCPREQUEST(tInterface *Iface, void *OfferPacket, int TypeOffset) { struct sDHCP_Message *msg; + int i; msg = (void*) ((char*)OfferPacket) + 8; // Reuses old data :) - msg->op = 1; - msg->options[TypeOffset+2] = 3; // DHCPREQUEST - msg->options[TypeOffset+3] = 255; + msg->op = 1; + msg->htype = 1; + msg->hlen = 6; + msg->hops = 0; + msg->xid = msg->xid; + msg->secs = htons(0); // TODO: Maintain times + msg->flags = htons(0); + memcpy(msg->chaddr, Iface->HWAddr, 6); + memset(msg->sname, 0, sizeof(msg->sname)); // Nuke the rest + memset(msg->file, 0, sizeof(msg->file)); // Nuke the rest + + i = 0; + msg->options[i++] = 53; // Message type = DHCPREQUEST + msg->options[i++] = 1; + msg->options[i++] = 3; + msg->options[i++] = 50; // Requested Address + msg->options[i++] = 4; + memcpy(msg->options + i, &msg->yiaddr, 4); i += 4; +// msg->options[i++] = 54; // Server identifier +// msg->options[i++] = 4; +// memcpy(msg->options + i, (char*)OfferPacket + 4, 4); i += 4; + msg->options[i++] = 255; - write(Iface->SocketFD, OfferPacket, 8 + sizeof(*msg) + TypeOffset + 4); - Iface->State = STATE_REQUEST_SENT; + // Clear last because yiaddr is needed in option setup + msg->ciaddr = htonl(0); + msg->yiaddr = htonl(0); + msg->siaddr = htonl(0); + msg->giaddr = htonl(0); + + // HACK + ((uint8_t*)OfferPacket)[4] = 255; + ((uint8_t*)OfferPacket)[5] = 255; + ((uint8_t*)OfferPacket)[6] = 255; + ((uint8_t*)OfferPacket)[7] = 255; + + write(Iface->SocketFD, OfferPacket, 8 + sizeof(*msg) + i); + Update_State(Iface, STATE_REQUEST_SENT); } int Handle_Packet(tInterface *Iface) @@ -314,6 +373,19 @@ int Handle_Packet(tInterface *Iface) return 0; } + + // Check if the packet is related to our requests + if( ntohl(msg->xid) != Iface->TransactionID ) { + _SysDebug("Transaction ID mis-match, ignoring (0x%x != 0x%x)", + ntohl(msg->xid), Iface->TransactionID); + return 0; + } + if( memcmp(msg->chaddr, Iface->HWAddr, 6) != 0 ) { + _SysDebug("Hardware address mis-match, ignoring"); + return 0; + } + + // Parse options i = 0; while( i < len - sizeof(*msg) - 8 && msg->options[i] != 255 ) { @@ -357,13 +429,41 @@ int Handle_Packet(tInterface *Iface) case 4: // DHCPDECLINE - ? break; case 5: // DHCPACK - // TODO: Apply address SetAddress(Iface, &msg->yiaddr, subnet_mask, router); + // Return 1 to remove from list return 1; } return 0; } +void Handle_Timeout(tInterface *Iface) +{ + switch(Iface->State) + { + case STATE_DISCOVER_SENT: + Send_DHCPDISCOVER(Iface); + break; + default: + _SysDebug("Timeout with state = %i", Iface->State); + break; + } +} + +void Update_State(tInterface *Iface, int newState) +{ + if( Iface->State != newState ) + { + Iface->Timeout = _SysTimestamp() + 500; + Iface->State = newState; + } + else + { + // TODO: Exponential backoff + Iface->Timeout = _SysTimestamp() + 3000; + _SysDebug("State %i repeated, timeout is 3000ms now", newState); + } +} + void SetAddress(tInterface *Iface, void *Addr, void *Mask, void *Router) { int mask_bits = 0; diff --git a/Usermode/Libraries/ld-acess.so_src/arch/syscalls.s.h b/Usermode/Libraries/ld-acess.so_src/arch/syscalls.s.h index 88cea59b..cd7b8fea 100644 --- a/Usermode/Libraries/ld-acess.so_src/arch/syscalls.s.h +++ b/Usermode/Libraries/ld-acess.so_src/arch/syscalls.s.h @@ -20,6 +20,7 @@ SYSCALL1(setgid, SYS_SETGID) SYSCALL1(SysSetName, SYS_SETNAME) SYSCALL2(SysGetName, SYS_GETNAME) +SYSCALL0(_SysTimestamp, SYS_GETTIME) SYSCALL1(SysSetPri, SYS_SETPRI) diff --git a/Usermode/Libraries/ld-acess.so_src/export.c b/Usermode/Libraries/ld-acess.so_src/export.c index 41ba01f9..1062d7e4 100644 --- a/Usermode/Libraries/ld-acess.so_src/export.c +++ b/Usermode/Libraries/ld-acess.so_src/export.c @@ -40,6 +40,8 @@ const struct { EXP(SysSetName), //EXP(SysGetName), + EXP(_SysTimestamp), + //EXP(SysSetPri), EXP(SysSendMessage), diff --git a/Usermode/include/acess/sys.h b/Usermode/include/acess/sys.h index cdd01879..e91ffb68 100644 --- a/Usermode/include/acess/sys.h +++ b/Usermode/include/acess/sys.h @@ -53,6 +53,7 @@ extern int getpid(void); extern int _SysSetFaultHandler(int (*Handler)(int)); extern void SysSetName(const char *Name); //extern int SysGetName(const char *Name); +extern int64_t _SysTimestamp(void); // --- Permissions --- extern int getuid(void); -- 2.20.1