From 4a720425b790e8a638d91c8c1a2e484095ab9906 Mon Sep 17 00:00:00 2001 From: likewise Date: Mon, 27 Jan 2003 13:58:45 +0000 Subject: [PATCH] Rebinding an active pcb did not check the given address/port against other bound pcb's. --- src/core/udp.c | 189 ++++++++++++++++++++++++++++++++++--------------- 1 file changed, 131 insertions(+), 58 deletions(-) diff --git a/src/core/udp.c b/src/core/udp.c index cd2e3ba0..21f33511 100644 --- a/src/core/udp.c +++ b/src/core/udp.c @@ -28,7 +28,7 @@ * * Author: Adam Dunkels * - * $Id: udp.c,v 1.14 2003/01/27 12:35:16 likewise Exp $ + * $Id: udp.c,v 1.15 2003/01/27 13:58:45 likewise Exp $ */ /*-----------------------------------------------------------------------------------*/ @@ -91,24 +91,25 @@ udp_lookup(struct ip_hdr *iphdr, struct netif *inp) struct udp_pcb *pcb; struct udp_hdr *udphdr; u16_t src, dest; - - PERF_START; - - udphdr = (struct udp_hdr *)(u8_t *)iphdr + IPH_HL(iphdr) * 4; + + PERF_START; + + udphdr = (struct udp_hdr *)(u8_t *)iphdr + IPH_HL(iphdr) * 4; src = NTOHS(udphdr->src); dest = NTOHS(udphdr->dest); - - pcb = pcb_cache; + + pcb = pcb_cache; if(pcb != NULL && - pcb->remote_port == src && - pcb->local_port == dest && - (ip_addr_isany(&pcb->remote_ip) || - ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src))) && - (ip_addr_isany(&pcb->local_ip) || - ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest)))) { + pcb->remote_port == src && + pcb->local_port == dest && + (ip_addr_isany(&pcb->remote_ip) || + ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src))) && + (ip_addr_isany(&pcb->local_ip) || + ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest)))) { return 1; - } else { + } + else { for(pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) { if(pcb->remote_port == src && pcb->local_port == dest && @@ -117,8 +118,8 @@ udp_lookup(struct ip_hdr *iphdr, struct netif *inp) (ip_addr_isany(&pcb->local_ip) || ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest)))) { pcb_cache = pcb; - break; - } + break; + } } if(pcb == NULL) { @@ -130,21 +131,32 @@ udp_lookup(struct ip_hdr *iphdr, struct netif *inp) (ip_addr_isany(&pcb->local_ip) || ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest)))) { break; - } + } } } } PERF_STOP("udp_lookup"); - + if(pcb != NULL) { return 1; - } else { + } + else { return 1; } } #endif /* LWIP_DEBUG */ -/*-----------------------------------------------------------------------------------*/ +/** + * Process an incoming UDP datagram. + * + * Given an incoming UDP datagram (as a chain of pbufs) this function + * finds a corresponding UDP PCB and + * + * @param pbuf pbuf to be demultiplexed to a UDP PCB. + * @param netif network interface on which the datagram was received. + * + * @see udp_disconnect() + */ void udp_input(struct pbuf *p, struct netif *inp) { @@ -299,7 +311,20 @@ udp_input(struct pbuf *p, struct netif *inp) PERF_STOP("udp_input"); } -/*-----------------------------------------------------------------------------------*/ +/** + * Send data using UDP. + * + * @param pcb UDP PCB used to send the data. + * @param pbuf chain of pbuf's to be sent. + * + * @return lwIP error code. + * - ERR_OK. Successful. No error occured. + * - ERR_MEM. Out of memory. + * - ERR_USE. The specified ipaddr and port are already bound to by + * another UDP PCB. + * + * @see udp_disconnect() + */ err_t udp_send(struct udp_pcb *pcb, struct pbuf *p) { @@ -309,18 +334,22 @@ udp_send(struct udp_pcb *pcb, struct pbuf *p) err_t err; struct pbuf *hdr; - DEBUGF(UDP_DEBUG, ("udp_send")); /* hdr will point to the UDP header pbuf if an extra header pbuf has to be allocated. */ hdr = NULL; + /* succeeding in adding an UDP header to first given pbuf in chain? */ if(pbuf_header(p, UDP_HLEN)) { + /* allocate header in new pbuf */ hdr = pbuf_alloc(PBUF_IP, UDP_HLEN, PBUF_RAM); + /* new header pbuf could not be allocated? */ if(hdr == NULL) { return ERR_MEM; } + /* chain header in front of given pbuf */ pbuf_chain(hdr, p); + /* have p point to header pbuf */ p = hdr; } DEBUGF(UDP_DEBUG, ("udp_send: got pbuf")); @@ -337,15 +366,18 @@ udp_send(struct udp_pcb *pcb, struct pbuf *p) #endif /* UDP_STATS */ return ERR_RTE; } - + /* using IP_ANY_ADDR? */ if(ip_addr_isany(&pcb->local_ip)) { + /* use network interface IP address as source address */ src_ip = &(netif->ip_addr); } else { + /* use UDP PCB local IP address as source address */ src_ip = &(pcb->local_ip); } DEBUGF(UDP_DEBUG, ("udp_send: sending datagram of length %d\n", p->tot_len)); + /* UDP Lite protocol? */ if(pcb->flags & UDP_FLAGS_UDPLITE) { DEBUGF(UDP_DEBUG, ("udp_send: UDP LITE packet length %u", p->tot_len)); /* set UDP message length in UDP header */ @@ -353,9 +385,9 @@ udp_send(struct udp_pcb *pcb, struct pbuf *p) /* calculate checksum */ udphdr->chksum = inet_chksum_pseudo(p, src_ip, &(pcb->remote_ip), IP_PROTO_UDP, pcb->chksum_len); - if(udphdr->chksum == 0x0000) { - udphdr->chksum = 0xffff; - } + /* chksum zero must become 0xffff, as zero means 'no checksum' */ + if(udphdr->chksum == 0x0000) udphdr->chksum = 0xffff; + /* output to IP */ err = ip_output_if(p, src_ip, &pcb->remote_ip, UDP_TTL, IP_PROTO_UDPLITE, netif); #if LWIP_SNMP > 0 snmp_inc_udpoutdatagrams(); @@ -365,20 +397,19 @@ udp_send(struct udp_pcb *pcb, struct pbuf *p) udphdr->len = htons(p->tot_len); /* calculate checksum */ if((pcb->flags & UDP_FLAGS_NOCHKSUM) == 0) { - udphdr->chksum = inet_chksum_pseudo(p, src_ip, &pcb->remote_ip, - IP_PROTO_UDP, p->tot_len); - if(udphdr->chksum == 0x0000) { - udphdr->chksum = 0xffff; - } + udphdr->chksum = inet_chksum_pseudo(p, src_ip, &pcb->remote_ip, IP_PROTO_UDP, p->tot_len); + /* chksum zero must become 0xffff, as zero means 'no checksum' */ + if(udphdr->chksum == 0x0000) udphdr->chksum = 0xffff; } DEBUGF(UDP_DEBUG, ("udp_send: UDP checksum %x", udphdr->chksum)); #if LWIP_SNMP > 0 snmp_inc_udpoutdatagrams(); #endif DEBUGF(UDP_DEBUG, ("udp_send: ip_output_if(,,,,IP_PROTO_UDP,)")); + /* output to IP */ err = ip_output_if(p, src_ip, &pcb->remote_ip, UDP_TTL, IP_PROTO_UDP, netif); } - + /* dechain and free the header pbuf */ if(hdr != NULL) { pbuf_dechain(hdr); pbuf_free(hdr); @@ -389,32 +420,47 @@ udp_send(struct udp_pcb *pcb, struct pbuf *p) #endif /* UDP_STATS */ return err; } -/*-----------------------------------------------------------------------------------*/ +/** + * Bind an UDP PCB. + * + * @param pcb UDP PCB to be bound with a local address ipaddr and port. + * @param ipaddr local IP address to bind with. Use IP_ADDR_ANY to + * bind to all local interfaces. + * @param port local UDP port to bind with. + * + * @return lwIP error code. + * - ERR_OK. Successful. No error occured. + * - ERR_USE. The specified ipaddr and port are already bound to by + * another UDP PCB. + * + * @see udp_disconnect() + */ err_t udp_bind(struct udp_pcb *pcb, struct ip_addr *ipaddr, u16_t port) { struct udp_pcb *ipcb; u8_t rebind = 0; - + /* Check for double bind and rebind of the same pcb */ for(ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) { + /* is this UDP PCB already on active list? */ if (pcb == ipcb) { - rebind = 1; - break; - } else - if (ipcb->local_port == port) { - if(ip_addr_isany(&(ipcb->local_ip)) || - ip_addr_isany(ipaddr) || - ip_addr_cmp(&(ipcb->local_ip), ipaddr)) { - /* Port/IP pair already bound */ - return ERR_USE; - } + rebind = 1; + } + /* port matches that of PCB in list? */ + if ((ipcb->local_port == port) && + /* IP address matches, or one is IP_ADDR_ANY? */ + (ip_addr_isany(&(ipcb->local_ip)) || + ip_addr_isany(ipaddr) || + ip_addr_cmp(&(ipcb->local_ip), ipaddr))) { + /* other PCB already binds to this local IP and port */ + return ERR_USE; } } - + /* bind local address */ ip_addr_set(&pcb->local_ip, ipaddr); pcb->local_port = port; - + /* We need to place the PCB on the list if not already there. */ if (rebind == 0) { pcb->next = udp_pcbs; @@ -424,7 +470,17 @@ udp_bind(struct udp_pcb *pcb, struct ip_addr *ipaddr, u16_t port) DEBUGF(UDP_DEBUG, ("udp_bind: bound to port %d\n", port)); return ERR_OK; } -/*-----------------------------------------------------------------------------------*/ +/** + * Connect an UDP PCB. + * + * @param pcb UDP PCB to be connected with remote address ipaddr and port. + * @param ipaddr remote IP address to connect with. + * @param port remote UDP port to connect with. + * + * @return lwIP error code + * + * @see udp_disconnect() + */ err_t udp_connect(struct udp_pcb *pcb, struct ip_addr *ipaddr, u16_t port) { @@ -436,11 +492,11 @@ udp_connect(struct udp_pcb *pcb, struct ip_addr *ipaddr, u16_t port) /* Insert UDP PCB into the list of active UDP PCBs. */ for(ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) { if(pcb == ipcb) { - /* Already on the list, just return. */ + /* already on the list, just return */ return ERR_OK; } } - /* We need to place the PCB on the list. */ + /* PCB not yet on the list, add PCB now */ pcb->next = udp_pcbs; udp_pcbs = pcb; return ERR_OK; @@ -458,37 +514,54 @@ udp_recv(struct udp_pcb *pcb, struct ip_addr *addr, u16_t port), void *recv_arg) { + /* remember recv() callback and user data */ pcb->recv = recv; pcb->recv_arg = recv_arg; } -/*-----------------------------------------------------------------------------------*/ +/** + * Remove an UDP PCB. + * + * @param pcb UDP PCB to be removed. The PCB is removed from the list of + * UDP PCB's and the data structure is freed from memory. + * + * @see udp_new() + */ void udp_remove(struct udp_pcb *pcb) { struct udp_pcb *pcb2; - - if(udp_pcbs == pcb) { + /* pcb to be removed is first in list? */ + if (udp_pcbs == pcb) { + /* make list start at 2nd pcb */ udp_pcbs = udp_pcbs->next; + /* pcb not 1st in list */ } else for(pcb2 = udp_pcbs; pcb2 != NULL; pcb2 = pcb2->next) { + /* find pcb in udp_pcbs list */ if(pcb2->next != NULL && pcb2->next == pcb) { + /* remove pcb from list */ pcb2->next = pcb->next; } } - memp_free(MEMP_UDP_PCB, pcb); } -/*-----------------------------------------------------------------------------------*/ +/** + * Create a UDP PCB. + * + * @return The UDP PCB which was created. NULL if the PCB data structure + * could not be allocated. + * + * @see udp_remove() + */ struct udp_pcb * udp_new(void) { struct udp_pcb *pcb; pcb = memp_malloc(MEMP_UDP_PCB); + /* could allocate UDP PCB? */ if(pcb != NULL) { - pcb->flags = 0; + /* initialize PCB to all zeroes */ memset(pcb, 0, sizeof(struct udp_pcb)); - return pcb; } - return NULL; - + return pcb; } /*-----------------------------------------------------------------------------------*/ #if UDP_DEBUG