- fix two segfaults (reported by Horst Kronstorfer)
authorBernhard Reutner-Fischer <rep.dot.nop@gmail.com>
Sat, 10 Jun 2006 14:15:03 +0000 (14:15 -0000)
committerBernhard Reutner-Fischer <rep.dot.nop@gmail.com>
Sat, 10 Jun 2006 14:15:03 +0000 (14:15 -0000)
- remove dangling file if get fails (spotted and fixed by Jason Schoon)
- shrink it (Bernhard Fischer)
Thanks, all!
   text    data     bss     dec     hex filename
   2684       0       0    2684     a7c networking/tftp.o.orig
   2748       0       0    2748     abc networking/tftp.o.allfixed
   2666       0       0    2666     a6a networking/tftp.o.+shrink

networking/tftp.c

index 527e3dc1169036afb4d6b7ce1d859dc20623e7e1..e32c5de385b50cee8a8369e93abd55cd8929c6ec 100644 (file)
 
 #include "busybox.h"
 
-//#define CONFIG_FEATURE_TFTP_DEBUG
 
-#define TFTP_BLOCKSIZE_DEFAULT 512 /* according to RFC 1350, don't change */
-#define TFTP_TIMEOUT 5             /* seconds */
+#define TFTP_BLOCKSIZE_DEFAULT 512     /* according to RFC 1350, don't change */
+#define TFTP_TIMEOUT 5 /* seconds */
+#define TFTP_NUM_RETRIES 5 /* number of retries */
 
-/* opcodes we support */
+/* RFC2348 says between 8 and 65464 */
+#define TFTP_OCTECTS_MIN 8
+#define TFTP_OCTECTS_MAX 65464
+
+static const char * const MODE_OCTET = "octet";
+#define MODE_OCTET_LEN 6 /* sizeof(MODE_OCTET)*/
 
+static const char * const OPTION_BLOCKSIZE = "blksize";
+#define OPTION_BLOCKSIZE_LEN 8 /* sizeof(OPTION_BLOCKSIZE) */
+
+/* opcodes we support */
 #define TFTP_RRQ   1
 #define TFTP_WRQ   2
 #define TFTP_DATA  3
@@ -47,7 +56,7 @@
 #define TFTP_ERROR 5
 #define TFTP_OACK  6
 
-static const char * const tftp_bb_error_msg[] = {
+static const char *const tftp_bb_error_msg[] = {
        "Undefined error",
        "File not found",
        "Access violation",
@@ -58,13 +67,10 @@ static const char * const tftp_bb_error_msg[] = {
        "No such user"
 };
 
-#ifdef CONFIG_FEATURE_TFTP_GET
-# define tftp_cmd_get 1
-#else
-# define tftp_cmd_get 0
-#endif
-#ifdef CONFIG_FEATURE_TFTP_PUT
-# define tftp_cmd_put (tftp_cmd_get+1)
+#define tftp_cmd_get ENABLE_FEATURE_TFTP_GET
+
+#if ENABLE_FEATURE_TFTP_PUT
+# define tftp_cmd_put (tftp_cmd_get+ENABLE_FEATURE_TFTP_PUT)
 #else
 # define tftp_cmd_put 0
 #endif
@@ -81,15 +87,15 @@ static int tftp_blocksize_check(int blocksize, int bufsize)
         */
 
        if ((bufsize && (blocksize > bufsize)) ||
-           (blocksize < 8) || (blocksize > 65464)) {
-               bb_error_msg("bad blocksize");
-               return 0;
+               (blocksize < TFTP_OCTECTS_MIN) || (blocksize > TFTP_OCTECTS_MAX)) {
+               bb_error_msg("bad blocksize");
+               return 0;
        }
 
        return blocksize;
 }
 
-static char *tftp_option_get(char *buf, int len, char *option)
+static char *tftp_option_get(char *buf, int len, const char const *option)
 {
        int opt_val = 0;
        int opt_found = 0;
@@ -97,25 +103,24 @@ static char *tftp_option_get(char *buf, int len, char *option)
 
        while (len > 0) {
 
-               /* Make sure the options are terminated correctly */
+               /* Make sure the options are terminated correctly */
 
-               for (k = 0; k < len; k++) {
-                       if (buf[k] == '\0') {
-                               break;
+               for (k = 0; k < len; k++) {
+                       if (buf[k] == '\0') {
+                               break;
                        }
                }
 
                if (k >= len) {
-                       break;
+                       break;
                }
 
                if (opt_val == 0) {
                        if (strcasecmp(buf, option) == 0) {
-                               opt_found = 1;
+                               opt_found = 1;
                        }
-               }
-               else {
-                       if (opt_found) {
+               } else {
+                       if (opt_found) {
                                return buf;
                        }
                }
@@ -133,38 +138,34 @@ static char *tftp_option_get(char *buf, int len, char *option)
 
 #endif
 
-static inline int tftp(const int cmd, const struct hostent *host,
-       const char *remotefile, int localfd, const unsigned short port, int tftp_bufsize)
+static int tftp(const int cmd, const struct hostent *host,
+                  const char *remotefile, const int localfd,
+                  const unsigned short port, int tftp_bufsize)
 {
-       const int cmd_get = cmd & tftp_cmd_get;
-       const int cmd_put = cmd & tftp_cmd_put;
-       const int bb_tftp_num_retries = 5;
-
+#define cmd_get  cmd & tftp_cmd_get
+#define cmd_put  cmd & tftp_cmd_put
        struct sockaddr_in sa;
        struct sockaddr_in from;
        struct timeval tv;
        socklen_t fromlen;
        fd_set rfds;
-       char *cp;
-       unsigned short tmp;
        int socketfd;
-       int len;
+       int len, itmp;
        int opcode = 0;
        int finished = 0;
-       int timeout = bb_tftp_num_retries;
+       int timeout = TFTP_NUM_RETRIES;
        unsigned short block_nr = 1;
+       unsigned short tmp;
+       char *cp;
 
-#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE
-       int want_option_ack = 0;
-#endif
+       USE_FEATURE_TFTP_BLOCKSIZE(int want_option_ack = 0;)
 
        /* Can't use RESERVE_CONFIG_BUFFER here since the allocation
         * size varies meaning BUFFERS_GO_ON_STACK would fail */
-       char *buf=xmalloc(tftp_bufsize + 4);
-
-       tftp_bufsize += 4;
+       char *buf=xmalloc(tftp_bufsize += 4);
 
-       if ((socketfd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) { /* bb_xsocket? */
+       if ((socketfd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
+               /* need to unlink the localfile, so don't use bb_xsocket here. */
                bb_perror_msg("socket");
                return EXIT_FAILURE;
        }
@@ -180,11 +181,9 @@ static inline int tftp(const int cmd, const struct hostent *host,
                   sizeof(sa.sin_addr));
 
        /* build opcode */
-
        if (cmd_get) {
                opcode = TFTP_RRQ;
        }
-
        if (cmd_put) {
                opcode = TFTP_WRQ;
        }
@@ -194,56 +193,49 @@ static inline int tftp(const int cmd, const struct hostent *host,
                cp = buf;
 
                /* first create the opcode part */
-
                *((unsigned short *) cp) = htons(opcode);
-
                cp += 2;
 
                /* add filename and mode */
-
-               if ((cmd_get && (opcode == TFTP_RRQ)) ||
-                       (cmd_put && (opcode == TFTP_WRQ))) {
+               if (((cmd_get) && (opcode == TFTP_RRQ)) ||
+                       ((cmd_put) && (opcode == TFTP_WRQ)))
+               {
                        int too_long = 0;
 
-                       /* see if the filename fits into buf */
-                       /* and fill in packet                */
-
+                       /* see if the filename fits into buf
+                        * and fill in packet.  */
                        len = strlen(remotefile) + 1;
 
                        if ((cp + len) >= &buf[tftp_bufsize - 1]) {
-                               too_long = 1;
-                       }
-                       else {
-                               safe_strncpy(cp, remotefile, len);
+                               too_long = 1;
+                       } else {
+                               safe_strncpy(cp, remotefile, len);
                                cp += len;
                        }
 
-                       if (too_long || ((&buf[tftp_bufsize - 1] - cp) < 6)) {
-                               bb_error_msg("too long remote-filename");
+                       if (too_long || ((&buf[tftp_bufsize - 1] - cp) < MODE_OCTET_LEN)) {
+                               bb_error_msg("remote filename too long");
                                break;
                        }
 
                        /* add "mode" part of the package */
-
-                       memcpy(cp, "octet", 6);
-                       cp += 6;
+                       memcpy(cp, MODE_OCTET, MODE_OCTET_LEN);
+                       cp += MODE_OCTET_LEN;
 
 #ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE
 
-                       len = tftp_bufsize - 4; /* data block size */
+                       len = tftp_bufsize - 4; /* data block size */
 
                        if (len != TFTP_BLOCKSIZE_DEFAULT) {
 
-                               if ((&buf[tftp_bufsize - 1] - cp) < 15) {
-                                       bb_error_msg("too long remote-filename");
+                               if ((&buf[tftp_bufsize - 1] - cp) < 15) {
+                                       bb_error_msg("remote filename too long");
                                        break;
                                }
 
                                /* add "blksize" + number of blocks  */
-
-                               memcpy(cp, "blksize", 8);
-                               cp += 8;
-
+                               memcpy(cp, OPTION_BLOCKSIZE, OPTION_BLOCKSIZE_LEN);
+                               cp += OPTION_BLOCKSIZE_LEN;
                                cp += snprintf(cp, 6, "%d", len) + 1;
 
                                want_option_ack = 1;
@@ -253,8 +245,8 @@ static inline int tftp(const int cmd, const struct hostent *host,
 
                /* add ack and data */
 
-               if ((cmd_get && (opcode == TFTP_ACK)) ||
-                       (cmd_put && (opcode == TFTP_DATA))) {
+               if (((cmd_get) && (opcode == TFTP_ACK)) ||
+                       ((cmd_put) && (opcode == TFTP_DATA))) {
 
                        *((unsigned short *) cp) = htons(block_nr);
 
@@ -262,7 +254,7 @@ static inline int tftp(const int cmd, const struct hostent *host,
 
                        block_nr++;
 
-                       if (cmd_put && (opcode == TFTP_DATA)) {
+                       if ((cmd_put) && (opcode == TFTP_DATA)) {
                                len = bb_full_read(localfd, cp, tftp_bufsize - 4);
 
                                if (len < 0) {
@@ -282,7 +274,7 @@ static inline int tftp(const int cmd, const struct hostent *host,
                /* send packet */
 
 
-               timeout = bb_tftp_num_retries;  /* re-initialize */
+               timeout = TFTP_NUM_RETRIES;     /* re-initialize */
                do {
 
                        len = cp - buf;
@@ -290,11 +282,11 @@ static inline int tftp(const int cmd, const struct hostent *host,
 #ifdef CONFIG_FEATURE_TFTP_DEBUG
                        fprintf(stderr, "sending %u bytes\n", len);
                        for (cp = buf; cp < &buf[len]; cp++)
-                               fprintf(stderr, "%02x ", (unsigned char)*cp);
+                               fprintf(stderr, "%02x ", (unsigned char) *cp);
                        fprintf(stderr, "\n");
 #endif
                        if (sendto(socketfd, buf, len, 0,
-                                       (struct sockaddr *) &sa, sizeof(sa)) < 0) {
+                                          (struct sockaddr *) &sa, sizeof(sa)) < 0) {
                                bb_perror_msg("send");
                                len = -1;
                                break;
@@ -316,10 +308,10 @@ static inline int tftp(const int cmd, const struct hostent *host,
                        FD_ZERO(&rfds);
                        FD_SET(socketfd, &rfds);
 
-                       switch (select(socketfd + 1, &rfds, NULL, NULL, &tv)) {
-                       case 1:
+                       itmp = select(socketfd + 1, &rfds, NULL, NULL, &tv);
+                       if (itmp == 1) {
                                len = recvfrom(socketfd, buf, tftp_bufsize, 0,
-                                               (struct sockaddr *) &from, &fromlen);
+                                                          (struct sockaddr *) &from, &fromlen);
 
                                if (len < 0) {
                                        bb_perror_msg("recvfrom");
@@ -337,9 +329,9 @@ static inline int tftp(const int cmd, const struct hostent *host,
 
                                /* fall-through for bad packets! */
                                /* discard the packet - treat as timeout */
-                               timeout = bb_tftp_num_retries;
+                               timeout = TFTP_NUM_RETRIES;
 
-                       case 0:
+                       } else if (itmp == 0) {
                                bb_error_msg("timeout");
 
                                timeout--;
@@ -349,7 +341,7 @@ static inline int tftp(const int cmd, const struct hostent *host,
                                }
                                break;
 
-                       default:
+                       } else {
                                bb_perror_msg("select");
                                len = -1;
                        }
@@ -362,7 +354,6 @@ static inline int tftp(const int cmd, const struct hostent *host,
 
                /* process received packet */
 
-
                opcode = ntohs(*((unsigned short *) buf));
                tmp = ntohs(*((unsigned short *) &buf[2]));
 
@@ -377,7 +368,7 @@ static inline int tftp(const int cmd, const struct hostent *host,
                                msg = &buf[4];
                                buf[tftp_bufsize - 1] = '\0';
                        } else if (tmp < (sizeof(tftp_bb_error_msg)
-                                         / sizeof(char *))) {
+                                                         / sizeof(char *))) {
 
                                msg = tftp_bb_error_msg[tmp];
                        }
@@ -388,55 +379,52 @@ static inline int tftp(const int cmd, const struct hostent *host,
 
                        break;
                }
-
 #ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE
                if (want_option_ack) {
 
-                        want_option_ack = 0;
+                       want_option_ack = 0;
 
-                        if (opcode == TFTP_OACK) {
+                       if (opcode == TFTP_OACK) {
 
-                                /* server seems to support options */
+                               /* server seems to support options */
 
-                                char *res;
+                               char *res;
 
-                                res = tftp_option_get(&buf[2], len-2,
-                                                      "blksize");
+                               res = tftp_option_get(&buf[2], len - 2, OPTION_BLOCKSIZE);
 
-                                if (res) {
-                                        int blksize = atoi(res);
+                               if (res) {
+                                       int blksize = atoi(res);
 
-                                        if (tftp_blocksize_check(blksize,
-                                                          tftp_bufsize - 4)) {
+                                       if (tftp_blocksize_check(blksize, tftp_bufsize - 4)) {
 
-                                                if (cmd_put) {
-                                                        opcode = TFTP_DATA;
-                                                }
-                                                else {
-                                                        opcode = TFTP_ACK;
-                                                }
+                                               if (cmd_put) {
+                                                       opcode = TFTP_DATA;
+                                               } else {
+                                                       opcode = TFTP_ACK;
+                                               }
 #ifdef CONFIG_FEATURE_TFTP_DEBUG
-                                                fprintf(stderr, "using blksize %u\n", blksize);
+                                               fprintf(stderr, "using %s %u\n", OPTION_BLOCKSIZE,
+                                                               blksize);
 #endif
-                                                tftp_bufsize = blksize + 4;
-                                                block_nr = 0;
-                                                continue;
-                                        }
-                                }
-                                /* FIXME:
-                                 * we should send ERROR 8 */
-                                bb_error_msg("bad server option");
-                                break;
-                        }
-
-                        bb_error_msg("warning: blksize not supported by server"
-                                  " - reverting to 512");
-
-                        tftp_bufsize = TFTP_BLOCKSIZE_DEFAULT + 4;
+                                               tftp_bufsize = blksize + 4;
+                                               block_nr = 0;
+                                               continue;
+                                       }
+                               }
+                               /* FIXME:
+                                * we should send ERROR 8 */
+                               bb_error_msg("bad server option");
+                               break;
+                       }
+
+                       bb_error_msg("warning: blksize not supported by server"
+                                                " - reverting to 512");
+
+                       tftp_bufsize = TFTP_BLOCKSIZE_DEFAULT + 4;
                }
 #endif
 
-               if (cmd_get && (opcode == TFTP_DATA)) {
+               if ((cmd_get) && (opcode == TFTP_DATA)) {
 
                        if (tmp == block_nr) {
 
@@ -455,7 +443,7 @@ static inline int tftp(const int cmd, const struct hostent *host,
                                continue;
                        }
                        /* in case the last ack disappeared into the ether */
-                       if ( tmp == (block_nr - 1) ) {
+                       if (tmp == (block_nr - 1)) {
                                --block_nr;
                                opcode = TFTP_ACK;
                                continue;
@@ -467,9 +455,9 @@ static inline int tftp(const int cmd, const struct hostent *host,
                        }
                }
 
-               if (cmd_put && (opcode == TFTP_ACK)) {
+               if ((cmd_put) && (opcode == TFTP_ACK)) {
 
-                       if (tmp == (unsigned short)(block_nr - 1)) {
+                       if (tmp == (unsigned short) (block_nr - 1)) {
                                if (finished) {
                                        break;
                                }
@@ -482,7 +470,6 @@ static inline int tftp(const int cmd, const struct hostent *host,
 
 #ifdef CONFIG_FEATURE_CLEAN_UP
        close(socketfd);
-
        free(buf);
 #endif
 
@@ -505,6 +492,7 @@ int tftp_main(int argc, char **argv)
 
 #ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE
        char *sblocksize = NULL;
+
 #define BS "b:"
 #define BS_ARG , &sblocksize
 #else
@@ -533,62 +521,66 @@ int tftp_main(int argc, char **argv)
 #elif defined(CONFIG_FEATURE_TFTP_GET) || defined(CONFIG_FEATURE_TFTP_PUT)
        bb_opt_complementally = GET_COMPL PUT_COMPL;
 #else
-       /* XXX: may be should #error ? */
+#error "Either CONFIG_FEATURE_TFTP_GET or CONFIG_FEATURE_TFTP_PUT must be defined"
 #endif
 
 
        cmd = bb_getopt_ulflags(argc, argv, GET PUT "l:r:" BS,
-                               &localfile, &remotefile BS_ARG);
-#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE
-       if(sblocksize) {
-               blocksize = atoi(sblocksize);
-               if (!tftp_blocksize_check(blocksize, 0)) {
-                       return EXIT_FAILURE;
-               }
-       }
-#endif
+                                                       &localfile, &remotefile BS_ARG);
 
        cmd &= (tftp_cmd_get | tftp_cmd_put);
 #ifdef CONFIG_FEATURE_TFTP_GET
-       if(cmd == tftp_cmd_get)
+       if (cmd == tftp_cmd_get)
                flags = O_WRONLY | O_CREAT | O_TRUNC;
 #endif
 #ifdef CONFIG_FEATURE_TFTP_PUT
-       if(cmd == tftp_cmd_put)
+       if (cmd == tftp_cmd_put)
                flags = O_RDONLY;
 #endif
 
-       if(localfile == NULL)
-           localfile = remotefile;
-       if(remotefile == NULL)
-           remotefile = localfile;
-       /* XXX: I corrected this, but may be wrong too. vodz */
-       if(localfile==NULL || strcmp(localfile, "-") == 0) {
-           fd = fileno((cmd==tftp_cmd_get)? stdout : stdin);
-       } else if (fd==-1) {
-           fd = open(localfile, flags, 0644);
+#ifdef CONFIG_FEATURE_TFTP_BLOCKSIZE
+       if (sblocksize) {
+               blocksize = atoi(sblocksize);
+               if (!tftp_blocksize_check(blocksize, 0)) {
+                       return EXIT_FAILURE;
+               }
+       }
+#endif
+
+       if (localfile == NULL)
+               localfile = remotefile;
+       if (remotefile == NULL)
+               remotefile = localfile;
+       if ((localfile == NULL && remotefile == NULL) || (argv[optind] == NULL))
+               bb_show_usage();
+
+       if (localfile == NULL || strcmp(localfile, "-") == 0) {
+               fd = (cmd == tftp_cmd_get) ? STDOUT_FILENO : STDIN_FILENO;
+       } else {
+               fd = open(localfile, flags, 0644); /* fail below */
        }
        if (fd < 0) {
                bb_perror_msg_and_die("local file");
        }
 
-       /* XXX: argv[optind] and/or argv[optind + 1] may be NULL! */
        host = xgethostbyname(argv[optind]);
        port = bb_lookup_port(argv[optind + 1], "udp", 69);
 
 #ifdef CONFIG_FEATURE_TFTP_DEBUG
        fprintf(stderr, "using server \"%s\", remotefile \"%s\", "
-               "localfile \"%s\".\n",
-               inet_ntoa(*((struct in_addr *) host->h_addr)),
-               remotefile, localfile);
+                       "localfile \"%s\".\n",
+                       inet_ntoa(*((struct in_addr *) host->h_addr)),
+                       remotefile, localfile);
 #endif
 
        result = tftp(cmd, host, remotefile, fd, port, blocksize);
 
 #ifdef CONFIG_FEATURE_CLEAN_UP
        if (!(fd == STDOUT_FILENO || fd == STDIN_FILENO)) {
-           close(fd);
+               close(fd);
        }
 #endif
-       return(result);
+       if (cmd == tftp_cmd_get && result != EXIT_SUCCESS)
+               unlink(localfile);
+       return (result);
 }